ALSA: pcm: Use guard() for PCM stream locks

Define guard() usage for PCM stream locking and use it in appropriate
places.

The pair of snd_pcm_stream_lock() and snd_pcm_stream_unlock() can be
presented with guard(pcm_stream_lock) now.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240227085306.9764-23-tiwai@suse.de

ALSA: hda: Upgrade stream-format infrastructure

Introduce a set of functions that ultimately facilite SDxFMT-related
calculations in atomic manner:

First, introduce snd_pcm_subformat_width() and snd_pcm_hw_params_bits()
helpers that separate the base functionality from the HDAudio-specific
one.

snd_hdac_format_normalize() - format converter. S20_LE, S24_LE and their
unsigned and BE friends are invalid from HDAudio perspective but still
can be specified as function argument due to compatibility reasons.

snd_hdac_stream_format_bits() - obtain just the bits-per-sample value.
Does not ignore subformat and msbits parameters.

snd_hdac_stream_format() and snd_hdac_spdif_stream_format() - obtain the
SDxFMT value given the audio format parameters. The former is stripped
away of spdif-related information. Useful for users that do not care
about them.

Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20231117120610.1755254-5-cezary.rojewski@intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Fix error checks of default read/write copy ops

copy_from/to_iter() returns the actually copied bytes, and the more
correct check should be to compare with the given bytes, instead of
zero-check.

Fixes: cf393babb37a ("ALSA: pcm: Add copy ops with iov_iter")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Closes: https://lore.kernel.org/r/20230902053044.GJ3390869@ZenIV
Link: https://lore.kernel.org/r/20230902061044.19366-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Drop obsoleted PCM copy_user and copy_kernel ops

Finally all users have been converted to the new PCM copy ops, let's
drop the obsoleted copy_kernel and copy_user ops completely.

Link: https://lore.kernel.org/r/20230815190136.8987-26-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Add copy ops with iov_iter

iov_iter is a universal interface to copy the data chunk from/to
user-space and kernel in a unified manner. This API can fit for ALSA
PCM copy ops, too; we had to split to copy_user and copy_kernel in the
past, and those can be unified to a single ops with iov_iter.

This patch adds a new PCM copy ops that passes iov_iter for copying
both kernel and user-space in the same way. This patch touches only
the ALSA PCM core part, and the actual users will be replaced in the
following patches.

The expansion of iov_iter is done in the PCM core right before calling
each copy callback. It's a bit suboptimal, but I took this now as
it's the most straightforward replacement. The more conversion to
iov_iter in the caller side is a TODO for future.

As of now, the old copy_user and copy_kernel ops are still kept.
Once after all users are converted, we'll drop the old copy_user and
copy_kernel ops, too.

Link: https://lore.kernel.org/r/20230815190136.8987-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: use exit controlled loop in snd_pcm_playback_silence()

We already know that `frames` is greater than zero, because we just
checked it. So we don't need to check the loop condition on the first
iteration.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230505155244.2312199-7-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: simplify top-up mode init in snd_pcm_playback_silence()

Inline the remaining call of snd_pcm_playback_hw_avail(). This makes
the top-up branch more congruent with the thresholded one, and allows
simplifying the handling of the corner cases.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230505155244.2312199-6-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: playback silence - move silence variable updates to separate function

The code tracking the added samples in thresholded mode and the code
tracking the just played samples in top-up mode are semantically
identical, so factor it out to a common function to enhance readability.

Co-developed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230505155244.2312199-5-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: playback silence - remove extra code

The removed condition handles de facto only one situation where
runtime->silence_filled variable is equal to runtime->buffer_size,
because this variable cannot go over the buffer size. This case is
implicitly caught by the required comparison of the noise distance
with the threshold.

Suggested-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230505155244.2312199-4-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: fix playback silence - correct incremental silencing

Commit 9a826ddba6e ("[ALSA] pcm core: fix silence_start calculations")
came with exactly the right commit message, but the patch just made
things broken in a different way: We'd fill at a too low address if the
area was already partially zeroed, so we'd under-fill. This affected
both thresholded mode (where it was somewhat less likely) and top-up
mode (where it would be the case consistently).

Co-developed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230505155244.2312199-3-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: fix playback silence - use the actual new_hw_ptr for the threshold mode

The snd_pcm_playback_hw_avail() function uses runtime->status->hw_ptr.
Unfortunately, in case when we call this function from snd_pcm_update_hw_ptr0(),
this variable contains the previous hardware pointer. Use the new_hw_ptr
argument to calculate hw_avail (filled samples by the user space) to
correct the threshold comparison.

The new_hw_ptr argument may also be set to ULONG_MAX which means the
initialization phase. In this case, use runtime->status->hw_ptr.

Suggested-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230505155244.2312199-2-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Revert "ALSA: pcm: rewrite snd_pcm_playback_silence()"

This reverts commit 9f656705c5faa18afb26d922cfc64f9fd103c38d.

There was a regression (in the top-up mode). Unfortunately, the patch
provided from the author of this commit is not easy to review.

Keep the updated and new comments in headers.
Also add a new comment that documents the missed API constraint which
led to the regression.

Reported-by: Jeff Chua <jeff.chua.linux@gmail.com>
Link: https://lore.kernel.org/r/CAAJw_ZsbTVd3Es373x_wTNDF7RknGhCD0r+NKUSwAO7HpLAkYA@mail.gmail.com
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230505155244.2312199-1-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: rewrite snd_pcm_playback_silence()

The auto-silencer supports two modes: "thresholded" to fill up "just
enough", and "top-up" to fill up "as much as possible". The two modes
used rather distinct code paths, which this patch unifies. The only
remaining distinction is how much we actually want to fill.

This fixes a bug in thresholded mode, where we failed to use new_hw_ptr,
resulting in under-fill.

Top-up mode is now more well-behaved and much easier to understand in
corner cases.

This also updates comments in the proximity of silencing-related data
structures.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230420113324.877164-1-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: fix wait_time calculations

... in wait_for_avail() and snd_pcm_drain().

t was calculated in seconds, so it would be pretty much always zero, to
be subsequently de-facto ignored due to being max(t, 10)'d. And then it
(i.e., 10) would be treated as secs, which doesn't seem right.

However, fixing it to properly calculate msecs would potentially cause
timeouts when using twice the period size for the default timeout (which
seems reasonable to me), so instead use the buffer size plus 10 percent
to be on the safe side ... but that still seems insufficient, presumably
because the hardware typically needs a moment to fire up. To compensate
for this, we up the minimal timeout to 100ms, which is still two orders
of magnitude less than the bogus minimum.

substream->wait_time was also misinterpreted as jiffies, despite being
documented as being in msecs. Only the soc/sof driver sets it - to 500,
which looks very much like msecs were intended.

Speaking of which, shouldn't snd_pcm_drain() also use substream->
wait_time?

As a drive-by, make the debug messages on timeout less confusing.

Signed-off-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230405201219.2197774-1-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: usb-audio: Fix recursive locking at XRUN during syncing

The recent support of low latency playback in USB-audio driver made
the snd_usb_queue_pending_output_urbs() function to be called via PCM
ack ops. In the new code path, the function is performed already in
the PCM stream lock. The problem is that, when an XRUN is detected,
the function calls snd_pcm_xrun() to notify, but snd_pcm_xrun() is
supposed to be called only outside the stream lock. As a result, it
leads to a deadlock of PCM stream locking.

For avoiding such a recursive locking, this patch adds an additional
check to the code paths in PCM core that call the ack callback; now it
checks the error code from the callback, and if it's -EPIPE, the XRUN
is handled in the PCM core side gracefully. Along with it, the
USB-audio driver code is changed to follow that, i.e. -EPIPE is
returned instead of the explicit snd_pcm_xrun() call when the function
is performed already in the stream lock.

Fixes: d5f871f89e21 ("ALSA: usb-audio: Improved lowlatency playback support")
Reported-and-tested-by: John Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20230317195128.3911155-1-john@metanate.com
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Reviewed-by; Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230320142838.494-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Avoid reference to status->state

In the PCM core and driver code, there are lots place referring to the
current PCM state via runtime->status->state. This patch introduced a
local PCM state in runtime itself and replaces those references with
runtime->state. It has improvements in two aspects:

- The reduction of a indirect access leads to more code optimization

- It avoids a possible (unexpected) modification of the state via mmap
of the status record

The status->state is updated together with runtime->state, so that
user-space can still read the current state via mmap like before,
too.

This patch touches only the ALSA core code. The changes in each
driver will follow in later patches.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220926135558.26580-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Use deferred fasync helper

For avoiding the potential deadlock via kill_fasync() call, use the
new fasync helpers to defer the invocation from timer API. Note that
it's merely a workaround.

Reported-by: syzbot+8285e973a41b5aa68902@syzkaller.appspotmail.com
Reported-by: syzbot+669c9abf11a6a011dd09@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20220728125945.29533-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock

syzbot caught a potential deadlock between the PCM
runtime->buffer_mutex and the mm->mmap_lock. It was brought by the
recent fix to cover the racy read/write and other ioctls, and in that
commit, I overlooked a (hopefully only) corner case that may take the
revert lock, namely, the OSS mmap. The OSS mmap operation
exceptionally allows to re-configure the parameters inside the OSS
mmap syscall, where mm->mmap_mutex is already held. Meanwhile, the
copy_from/to_user calls at read/write operations also take the
mm->mmap_lock internally, hence it may lead to a AB/BA deadlock.

A similar problem was already seen in the past and we fixed it with a
refcount (in commit b248371628aa). The former fix covered only the
call paths with OSS read/write and OSS ioctls, while we need to cover
the concurrent access via both ALSA and OSS APIs now.

This patch addresses the problem above by replacing the buffer_mutex
lock in the read/write operations with a refcount similar as we've
used for OSS. The new field, runtime->buffer_accessing, keeps the
number of concurrent read/write operations. Unlike the former
buffer_mutex protection, this protects only around the
copy_from/to_user() calls; the other codes are basically protected by
the PCM stream lock. The refcount can be a negative, meaning blocked
by the ioctls. If a negative value is seen, the read/write aborts
with -EBUSY. In the ioctl side, OTOH, they check this refcount, too,
and set to a negative value for blocking unless it's already being
accessed.

Reported-by: syzbot+6e5c88838328e99c7e1c@syzkaller.appspotmail.com
Fixes: dca947d4d26d ("ALSA: pcm: Fix races among concurrent read/write and buffer changes")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/000000000000381a0d05db622a81@google.com
Link: https://lore.kernel.org/r/20220330120903.4738-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Fix races among concurrent read/write and buffer changes

In the current PCM design, the read/write syscalls (as well as the
equivalent ioctls) are allowed before the PCM stream is running, that
is, at PCM PREPARED state. Meanwhile, we also allow to re-issue
hw_params and hw_free ioctl calls at the PREPARED state that may
change or free the buffers, too. The problem is that there is no
protection against those mix-ups.

This patch applies the previously introduced runtime->buffer_mutex to
the read/write operations so that the concurrent hw_params or hw_free
call can no longer interfere during the operation. The mutex is
unlocked before scheduling, so we don't take it too long.

Cc: <stable@vger.kernel.org>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220322170720.3529-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: introduce INFO_NO_REWINDS flag

When the hardware can only deal with a monotonically increasing
appl_ptr, this flag can be set.

In case the application requests a rewind, be it with a
snd_pcm_rewind() or with a direct change of a mmap'ed pointer followed
by a SNDRV_PCM_IOCTL_SYNC_PTR, this patch checks if a rewind
occurred and returns an error.

Credits to Takashi Iwai for identifying the path with SYNC_PTR and
suggesting the pointer checks.

Suggested-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20211119230852.206310-3-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

ALSA: pcm: unconditionally check if appl_ptr is in 0..boundary range

In some cases, the appl_ptr passed by userspace is not checked before
being used. This patch adds an unconditional check and returns an
error code should the appl_ptr exceed the ALSA 'boundary'.

Suggested-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20211119230852.206310-2-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

ALSA: memalloc: Support for non-contiguous page allocation

This patch adds the support for allocation of non-contiguous DMA pages
in the common memalloc helper. It's another SG-buffer type, but
unlike the existing one, this is directional and requires the explicit
sync / invalidation of dirty pages on non-coherent architectures.

For this enhancement, the following points are changed:
- snd_dma_device stores the DMA direction.
- snd_dma_device stores need_sync flag indicating whether the explicit
sync is required or not.
- A new variant of helper functions, snd_dma_alloc_dir_pages() and
*_all() are introduced; the old snd_dma_alloc_pages() and *_all()
kept as just wrappers with DMA_BIDIRECTIONAL.
- A new helper snd_dma_buffer_sync() is introduced; this gets called
in the appropriate places.
- A new allocation type, SNDRV_DMA_TYPE_NONCONTIG, is introduced.

When the driver allocates pages with this new type, and it may require
the SNDRV_PCM_INFO_EXPLICIT_SYNC flag set to the PCM hardware.info for
taking the full control of PCM applptr and hwptr changes (that implies
disabling the mmap of control/status data). When the buffer
allocation is managed by snd_pcm_set_managed_buffer(), this flag is
automatically set depending on the result of dma_need_sync()
internally. Otherwise, if the buffer is managed manually, the driver
has to set the flag explicitly, too.

The explicit sync between CPU and device for non-coherent memory is
performed at the points before and after read/write transfer as well
as the applptr/hwptr syncptr ioctl. In the case of mmap mode,
user-space is supposed to call the syncptr ioctl with the hwptr flag
to update and fetch the status at first; this corresponds to CPU-sync.
Then user-space advances the applptr via syncptr ioctl again with
applptr flag, and this corresponds to the device sync with flushing.

Other than the DMA direction and the explicit sync, the usage of this
new buffer type is almost equivalent with the existing
SNDRV_DMA_TYPE_DEV_SG; you can get the page and the address via
snd_sgbuf_get_page() and snd_sgbuf_get_addr(), also calculate the
continuous pages via snd_sgbuf_get_chunk_size().

For those SG-page handling, the non-contig type shares the same ops
with the vmalloc handler. As we do always vmap the SG pages at first,
the actual address can be deduced from the vmapped address easily
without iterating the SG-list.

Link: https://lore.kernel.org/r/20211017074859.24112-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: fix divide error in snd_pcm_lib_ioctl

Syzkaller reported a divide error in snd_pcm_lib_ioctl. fifo_size
is of type snd_pcm_uframes_t(unsigned long). If frame_size
is 0x100000000, the error occurs.

Fixes: a9960e6a293e ("ALSA: pcm: fix fifo_size frame calculation")
Signed-off-by: Zubin Mithra <zsm@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210827153735.789452-1-zsm@chromium.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: add snd_pcm_period_elapsed() variant without acquiring lock of PCM substream

Current implementation of ALSA PCM core has a kernel API,
snd_pcm_period_elapsed(), for drivers to queue event to awaken processes
from waiting for available frames. The function voluntarily acquires lock
of PCM substream, therefore it is not called in process context for any
PCM operation since the lock is already acquired.

It is convenient for packet-oriented driver, at least for drivers to audio
and music unit in IEEE 1394 bus. The drivers are allowed by Linux
FireWire subsystem to process isochronous packets queued till recent
isochronous cycle in process context in any time.

This commit adds snd_pcm_period_elapsed() variant,
snd_pcm_period_elapsed_without_lock(), for drivers to queue the event in
the process context.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210610031733.56297-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: use krealloc_array()

Use the helper that checks for overflows internally instead of manually
calculating the size of the new array.

Link: https://lkml.kernel.org/r/20201109110654.12547-4-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christian Knig <christian.koenig@amd.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: David Rientjes <rientjes@google.com>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: "Michael S . Tsirkin" <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ALSA: fix kernel-doc markups

Kernel-doc markups should use this format:
identifier - description

There is a common comment marked, instead, with kernel-doc
notation.

Some identifiers have different names between their prototypes
and the kernel-doc markup.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/535182d6f55d7a7de293dda9676df68f5f60afc6.1603469755.git.mchehab+huawei@kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: fix incorrect hw_base increase

There is a corner case that ALSA keeps increasing the hw_ptr but DMA
already stop working/updating the position for a long time.

In following log we can see the position returned from DMA driver does
not move at all but the hw_ptr got increased at some point of time so
snd_pcm_avail() will return a large number which seems to be a buffer
underrun event from user space program point of view. The program
thinks there is space in the buffer and fill more data.

[ 418.510086] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 4096 avail 12368
[ 418.510149] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 6910 avail 9554
...
[ 418.681052] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 15102 avail 1362
[ 418.681130] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 16464 avail 0
[ 418.726515] sound pcmC0D5p: pos 96 hw_ptr 16464 appl_ptr 16464 avail 16368

This is because the hw_base will be increased by runtime->buffer_size
frames unconditionally if the hw_ptr is not updated for over half of
buffer time. As the hw_base increases, so does the hw_ptr increased
by the same number.

The avail value returned from snd_pcm_avail() could exceed the limit
(buffer_size) easily becase the hw_ptr itself got increased by same
buffer_size samples when the corner case happens. In following log,
the buffer_size is 16368 samples but the avail is 21810 samples so
CRAS server complains about it.

[ 418.851755] sound pcmC0D5p: pos 96 hw_ptr 16464 appl_ptr 27390 avail 5442
[ 418.926491] sound pcmC0D5p: pos 96 hw_ptr 32832 appl_ptr 27390 avail 21810

cras_server[1907]: pcm_avail returned frames larger than buf_size:
sof-glkda7219max: :0,5: 21810 > 16368

By updating runtime->hw_ptr_jiffies each time the HWSYNC is called,
the hw_base will keep the same when buffer stall happens at long as
the interval between each HWSYNC call is shorter than half of buffer
time.

Following is a log captured by a patched kernel. The hw_base/hw_ptr
value is fixed in this corner case and user space program should be
aware of the buffer stall and handle it.

[ 293.525543] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 4096 avail 12368
[ 293.525606] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 6880 avail 9584
[ 293.525975] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 10976 avail 5488
[ 293.611178] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 15072 avail 1392
[ 293.696429] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 16464 avail 0
...
[ 381.139517] sound pcmC0D5p: pos 96 hw_ptr 96 appl_ptr 16464 avail 0

Signed-off-by: Brent Lu <brent.lu@intel.com>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1589776238-23877-1-git-send-email-brent.lu@intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: More constifications

Apply const prefix to more possible places: the string tables for PCM
format and co, the table for the PCM type helpers, etc.

Just for minor optimization and no functional changes.

Link: https://lore.kernel.org/r/20200105144823.29547-6-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: control: Add verification for kctl accesses

The current implementation of ALSA control API fully relies on the
callbacks of each driver, and there is no verification of the values
passed via API. This patch is an attempt to improve the situation
slightly by adding the validation code for the values stored via info
and get callbacks.

The patch adds a new kconfig, CONFIG_SND_CTL_VALIDATION. It depends
on CONFIG_SND_DEBUG and off as default since the validation would
require a slight overhead including the additional call of info
callback at each get callback invocation.

When this config is enabled, the values stored by each info callback
invocation are verified, namely:
- Whether the info type is valid
- Whether the number of enum items is non-zero
- Whether the given info count is within the allowed boundary

Similarly, the values stored at each get callback are verified as
well:
- Whether the values are within the given range
- Whether the values are aligned with the given step
- Whether any further changes are seen in the data array over the
given info count

The last point helps identifying a possibly invalid data type access,
typically a case where the info callback declares the type being
SNDRV_CTL_ELEM_TYPE_ENUMERATED while the get/put callbacks store
the values in value.integer.value[] array.

When a validation fails, the ALSA core logs an error message including
the device and the control ID, and the API call also returns an
error. So, with the new validation turned on, the driver behavior
difference may be visible on user-space, too -- it's intentional,
though, so that we can catch an error more clearly.

The patch also introduces a new ctl access type,
SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK. A driver may pass this flag with
other access bits to indicate that the ctl element won't be verified.
It's useful when a driver code is specially written to access the data
greater than info->count size by some reason. For example, this flag
is actually set now in HD-audio HDMI codec driver which needs to clear
the data array in the case of the disconnected monitor.

Also, the PCM channel-map helper code is slightly modified to avoid
the false-positive hit by this validation code, too.

Link: https://lore.kernel.org/r/20200104083556.27789-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: control: remove useless assignment in .info callback of PCM chmap element

Control elements for PCM chmap return information to userspace abount
the maximum number of available PCM channels as the number of values
in the element.

In current implementation the number is once initialized to zero, then
assigned to. This is useless and this commit fixes it.

Fixes: 2d3391ec0ecc ("ALSA: PCM: channel mapping API implementation")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20191214131351.28950-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: add new 32-bit layout for snd_pcm_mmap_status/control

The snd_pcm_mmap_status and snd_pcm_mmap_control interfaces are one of the
trickiest areas to get right when moving to 64-bit time_t in user space.

The snd_pcm_mmap_status structure layout is incompatible with user space
that uses a 64-bit time_t, so we need a new layout for it. Since the
SNDRV_PCM_IOCTL_SYNC_PTR ioctl combines it with snd_pcm_mmap_control
into snd_pcm_sync_ptr, we need to change those two as well.

Both structures are also exported via an mmap() operation on certain
architectures, and this suffers from incompatibility between 32-bit
and 64-bit user space. As we have to change both structures anyway,
this is a good opportunity to fix the mmap() problem as well, so let's
standardize on the existing 64-bit layout of the structure where possible.

The downside is that we lose mmap() support for existing 32-bit x86 and
powerpc applications, adding that would introduce very noticeable runtime
overhead and complexity. My assumption here is that not too many people
will miss the removed feature, given that:

- Almost all x86 and powerpc users these days are on 64-bit kernels,
the majority of today's 32-bit users are on architectures that never
supported mmap (ARM, MIPS, ...).
- It never worked in compat mode (it was intentionally disabled there)
- The application already needs to work with a fallback to
SNDRV_PCM_IOCTL_SYNC_PTR, which will keep working with both the old
and new structure layout.

Both the ioctl() and mmap() based interfaces are changed at the same
time, as they are based on the same structures. Unlike other interfaces,
we change the uapi header to export both the traditional structure and
a version that is portable between 32-bit and 64-bit user space code
and that corresponds to the existing 64-bit layout. We further check the
__USE_TIME_BITS64 macro that will be defined by future C library versions
whenever we use the new time_t definition, so any existing user space
source code will not see any changes until it gets rebuilt against a new
C library. However, the new structures are all visible in addition to the
old ones, allowing applications to explicitly request the new structures.

In order to detect the difference between the old snd_pcm_mmap_status and
the new __snd_pcm_mmap_status64 structure from the ioctl command number,
we rely on one quirk in the structure definition: snd_pcm_mmap_status
must be aligned to alignof(time_t), which leads the compiler to insert
four bytes of padding in struct snd_pcm_sync_ptr after 'flags' and a
corresponding change in the size of snd_pcm_sync_ptr itself. On x86-32
(and only there), the compiler doesn't use 64-bit alignment in structure,
so I'm adding an explicit pad in the structure that has no effect on the
existing 64-bit architectures but ensures that the layout matches for x86.

The snd_pcm_uframes_t type compatibility requires another hack: we can't
easily make that 64 bit wide, so I leave the type as 'unsigned long',
but add padding before and after it, to ensure that the data is properly
aligned to the respective 64-bit field in the in-kernel structure.

For the SNDRV_PCM_MMAP_OFFSET_STATUS/CONTROL constants that are used
as the virtual file offset in the mmap() function, we also have to
introduce new constants that depend on hte __USE_TIME_BITS64 macro:
The existing macros are renamed to SNDRV_PCM_MMAP_OFFSET_STATUS_OLD
and SNDRV_PCM_MMAP_OFFSET_CONTROL_OLD, they continue to work fine on
64-bit architectures, but stop working on native 32-bit user space.
The replacement _NEW constants are now used by default for user space
built with __USE_TIME_BITS64, those now work on all new kernels for x86,
ppc and alpha (32 and 64 bit, native and compat). It might be a good idea
for a future alsa-lib to support both the _OLD and _NEW macros and use
the corresponding structures directly. Unmodified alsa-lib source code
will retain the current behavior, so it will no longer be able to use
mmap() for the status/control structures on 32-bit systems, until either
the C library gets updated to 64-bit time_t or alsa-lib gets updated to
support both mmap() layouts.

Co-developed-with: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

ALSA: Replace timespec with timespec64

Since timespec is not year 2038 safe on 32bit system, and we need to
convert all timespec variables to timespec64 type for sound subsystem.

This patch is used to do preparation for following patches, that will
convert all structures defined in uapi/sound/asound.h to use 64-bit
time_t.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

ALSA: pcm: Fix stream lock usage in snd_pcm_period_elapsed()

If the nullity check for `substream->runtime` is outside of the lock
region, it is possible to have a null runtime in the critical section
if snd_pcm_detach_substream is called right before the lock.

Signed-off-by: paulhsia <paulhsia@chromium.org>
Link: https://lore.kernel.org/r/20191112171715.128727-2-paulhsia@chromium.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ALSA: pcm: Comment why read blocks when PCM is not running

This avoids bringing back the problem introduced by
62ba568f7aef ("ALSA: pcm: Return 0 when size <
start_threshold in capture") and fixed in 00a399cad1a0
("ALSA: pcm: Revert capture stream behavior change in
blocking mode"), which prevented the user from starting
capture from another thread.

Signed-off-by: Ricardo Biehl Pasquali <pasqualirb@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Revert capture stream behavior change in blocking mode

In the commit 62ba568f7aef ("ALSA: pcm: Return 0 when size <
start_threshold in capture"), we changed the behavior of
__snd_pcm_lib_xfer() to return immediately with 0 when a capture
stream has a high start_threshold. This was intended to be a
correction of the behavior consistency and looked harmless, but this
was the culprit of the recent breakage reported by syzkaller, which
was fixed by the commit e190161f96b8 ("ALSA: pcm: Fix tight loop of
OSS capture stream").

At the time for the OSS fix, I didn't touch the behavior for ALSA
native API, as assuming that this behavior actually is good. But this
turned out to be also broken actually for a similar deployment,
e.g. one thread goes to a write loop in blocking mode while another
thread controls the start/stop of the stream manually.

Overall, the original commit is harmful, and it brings less merit to
keep that behavior. Let's revert it.

Fixes: 62ba568f7aef ("ALSA: pcm: Return 0 when size < start_threshold in capture")
Fixes: e190161f96b8 ("ALSA: pcm: Fix tight loop of OSS capture stream")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Fix tight loop of OSS capture stream

When the trigger=off is passed for a PCM OSS stream, it sets the
start_threshold of the given substream to the boundary size, so that
it won't be automatically started. This can be problematic for a
capture stream, unfortunately, as detected by syzkaller. The scenario
is like the following:

- In __snd_pcm_lib_xfer() that is invoked from snd_pcm_oss_read()
loop, we have a check whether the stream was already started or the
stream can be auto-started.
- The function at this check returns 0 with trigger=off since we
explicitly disable the auto-start.
- The loop continues and repeats calling __snd_pcm_lib_xfer() tightly,
which may lead to an RCU stall.

This patch fixes the bug by simply allowing the wait for non-started
stream in the case of OSS capture. For native usages, it's supposed
to be done by the caller side (which is user-space), hence it returns
zero like before.

(In theory, __snd_pcm_lib_xfer() could wait even for the native API
usage cases, too; but I'd like to stay in a safer side for not
breaking the existing stuff for now.)

Reported-by: syzbot+fbe0496f92a0ce7b786c@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Use the common error path in __snd_pcm_lib_xfer()

An open-coded error path in __snd_pcm_lib_xfer() can be replaced with
the simple goto to the common error path. This also makes the error
handling more consistent, i.e. when some samples have been already
processed, return that size instead of the error code.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Update hardware pointer before start capture

This ensures the transfer loop won't waste a run to read
the few frames (if any) between start and hw_ptr update.
It will wait for the next interrupt with wait_for_avail().

Signed-off-by: Ricardo Biehl Pasquali <pasqualirb@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Return 0 when size < start_threshold in capture

In __snd_pcm_lib_xfer(), when capture, if state is PREPARED
and size is less than start_threshold nothing can be done.
As there is no error, 0 is returned.

Signed-off-by: Ricardo Biehl Pasquali <pasqualirb@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Fix snd_interval_refine first/last with open min/max

Without this commit the following intervals [x y), (x y) were be
replaced to (y-1 y) by snd_interval_refine_last(). This was also done
if y-1 is part of the previous interval.
With this changes it will be replaced with [y-1 y) in case of y-1 is
part of the previous interval. A similar behavior will be used for
snd_interval_refine_first().

This commit adapts the changes for alsa-lib of commit
9bb985c ("pcm: snd_interval_refine_first/last: exclude value only if
also excluded before")

Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Allow drivers to set R/W wait time.

Currently ALSA core blocks userspace for about 10 seconds for PCM R/W IO.
This needs to be configurable for modern hardware like DSPs where no
pointer update in milliseconds can indicate terminal DSP errors.

Add a substream variable to set the wait time in ms. This allows userspace
and drivers to recover more quickly from terminal DSP errors.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: trace XRUN event at injection, too

The PCM xrun injection triggers directly snd_pcm_stop() without the
standard xrun handler, hence it's not recorded on the event buffer.
Ditto for snd_pcm_stop_xrun() call and SNDRV_PCM_IOCTL_XRUN ioctl.
They are inconvenient from the debugging POV.

Let's make them to trigger XRUN via the standard helper more
consistently.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Clean up with snd_pcm_avail() and snd_pcm_hw_avail() helpers

Introduce two new direction-neutral helpers to calculate the avail and
hw_avail values, and clean up the code with them.

The two separated forward and rewind functions are gathered to the
unified functions.

No functional change but only code reductions.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Use krealloc() for resizing the rules array

Just a minor simplification. Change from kcalloc() shouldn't matter
as each array element is fully initialized.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Remove yet superfluous WARN_ON()

muldiv32() contains a snd_BUG_ON() (which is morphed as WARN_ON() with
debug option) for checking the case of 0 / 0. This would be helpful
if this happens only as a logical error; however, since the hw refine
is performed with any data set provided by user, the inconsistent
values that can trigger such a condition might be passed easily.
Actually, syzbot caught this by passing some zero'ed old hw_params
ioctl.

So, having snd_BUG_ON() there is simply superfluous and rather
harmful to give unnecessary confusions. Let's get rid of it.

Reported-by: syzbot+7e6ee55011deeebce15d@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Set config update bits only when really changed

The PCM config space refine codes touch the parameter rmask and cmask
bits when the given config parameter is changed. But in most places
it checks only whether the changed value is non-zero or not, and they
don't consider whether a negative error value is returned. This will
lead to the incorrect update bits set upon the error path.

Fix the codes to check properly the return code whether it's really
updated or an error.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Remove incorrect snd_BUG_ON() usages

syzkaller triggered kernel warnings through PCM OSS emulation at
closing a stream:
WARNING: CPU: 0 PID: 3502 at sound/core/pcm_lib.c:1635
snd_pcm_hw_param_first+0x289/0x690 sound/core/pcm_lib.c:1635
Call Trace:
....
snd_pcm_hw_param_near.constprop.27+0x78d/0x9a0 sound/core/oss/pcm_oss.c:457
snd_pcm_oss_change_params+0x17d3/0x3720 sound/core/oss/pcm_oss.c:969
snd_pcm_oss_make_ready+0xaa/0x130 sound/core/oss/pcm_oss.c:1128
snd_pcm_oss_sync+0x257/0x830 sound/core/oss/pcm_oss.c:1638
snd_pcm_oss_release+0x20b/0x280 sound/core/oss/pcm_oss.c:2431
__fput+0x327/0x7e0 fs/file_table.c:210
....

This happens while it tries to open and set up the aloop device
concurrently. The warning above (invoked from snd_BUG_ON() macro) is
to detect the unexpected logical error where snd_pcm_hw_refine() call
shouldn't fail. The theory is true for the case where the hw_params
config rules are static. But for an aloop device, the hw_params rule
condition does vary dynamically depending on the connected target;
when another device is opened and changes the parameters, the device
connected in another side is also affected, and it caused the error
from snd_pcm_hw_refine().

That is, the simplest "solution" for this is to remove the incorrect
assumption of static rules, and treat such an error as a normal error
path. As there are a couple of other places using snd_BUG_ON()
incorrectly, this patch removes these spurious snd_BUG_ON() calls.

Reported-by: syzbot+6f11c7e2a1b91d466432@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: update tstamp only if audio_tstamp changed

commit 3179f6200188 ("ALSA: core: add .get_time_info") had a side effect
of changing the behaviour of the PCM runtime tstamp. Prior to this
change tstamp was not updated by snd_pcm_update_hw_ptr0() unless the
hw_ptr had moved, after this change tstamp was always updated.

For an application using alsa-lib, doing snd_pcm_readi() followed by
snd_pcm_status() to estimate the age of the read samples by subtracting
status->avail * [sample rate] from status->tstamp this change degraded
the accuracy of the estimate on devices where the pcm hw does not
provide a granular hw_ptr, e.g., devices using
soc-generic-dmaengine-pcm.c and a dma-engine with residue_granularity
DMA_RESIDUE_GRANULARITY_DESCRIPTOR. The accuracy of the estimate
depended on the latency between the PCM hw completing a period and the
driver called snd_pcm_period_elapsed() to notify ALSA core, typically
determined by interrupt handling latency. After the change the accuracy
of the estimate depended on the latency between the PCM hw completing a
period and the application calling snd_pcm_status(), determined by the
scheduling of the application process. The maximum error of the
estimate is one period length in both cases, but the error average and
variance is smaller when it depends on interrupt latency.

Instead of always updating tstamp, update it only if audio_tstamp
changed.

Fixes: 3179f6200188 ("ALSA: core: add .get_time_info")
Suggested-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Henrik Eriksson <henrik.eriksson@axis.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sched/wait: Rename wait_queue_t => wait_queue_entry_t

Rename:

wait_queue_t => wait_queue_entry_t

'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
which had to carry the name.

Start sorting this out by renaming it to 'wait_queue_entry_t'.

This also allows the real structure name 'struct __wait_queue' to
lose its double underscore and become 'struct wait_queue_entry',
which is the more canonical nomenclature for such data types.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

ALSA: pcm: Fix possible inconsistent appl_ptr update via mmap

The ALSA PCM core refers to the appl_ptr value stored on the mmapped
page that is shared between kernel and user-space. Although the
reference is performed in the PCM stream lock, it doesn't guarantee
the atomic access when the value gets updated concurrently from the
user-space on another CPU.

In most of codes, this is no big problem, but still there are a few
places that may result in slight inconsistencies because they access
runtime->control->appl_ptr multiple times; that is, the second read
might be a different value from the first value. It can be even
backward or jumping, as we have no control for it. Hence, the
calculation may give an unexpected value. Luckily, there is no
security vulnerability by that, as far as I've checked. But still we
should address it.

This patch tries to reduce such possible cases. The fix is simple --
we just read once, store it to a local variable and use it for the
rest calculations. The READ_ONCE() macro is used for it in order to
avoid the ill-effect by possible compiler optimizations.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Follow standard EXPORT_SYMBOL() declarations

Just a tidy up to follow the standard EXPORT_SYMBOL*() declarations
in order to improve grep-ability.

- Remove superfluous blank line before EXPORT_SYMBOL*() lines

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Don't treat NULL chmap as a fatal error

The standard PCM chmap helper callbacks treat the NULL info->chmap as
a fatal error and spews the kernel warning with stack trace when
CONFIG_SND_DEBUG is on. This was OK, originally it was supposed to be
always static and non-NULL. But, as the recent addition of Intel LPE
audio driver shows, the chmap content may vary dynamically, and it can
be even NULL when disconnected. The user still sees the kernel
warning unnecessarily.

For clearing such a confusion, this patch simply removes the
snd_BUG_ON() in each place, just returns an error without warning.

Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: remove SNDRV_PCM_IOCTL1_INFO internal command

Drivers can implement 'struct snd_pcm_ops.ioctl' to handle some requests
from ALSA PCM core. These requests are internal purpose in kernel land.
Usually common set of operations are used for it.

SNDRV_PCM_IOCTL1_INFO is one of the requests. According to code comment,
it has been obsoleted in the old days.

We can see old releases in ftp.alsa-project.org. The command was firstly
introduced in v0.5.0 release as SND_PCM_IOCTL1_INFO, to allow drivers to
fill data of 'struct snd_pcm_channel_info' type. In v0.9.0 release,
this was obsoleted by the other commands for ioctl(2) such as
SNDRV_PCM_IOCTL_CHANNEL_INFO.

This commit removes the long-abandoned command, bye.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Skip ack callback without actual appl_ptr update

We call ack callback whenever appl_ptr gets updated via
pcm_lib_apply_appl_ptr(). There are various code paths to call this
function. A part of them are for read/write/forward/rewind, where the
appl_ptr is always changed and thus the call of ack is mandatory.
OTOH, another part of code paths are from the explicit user call,
e.g. via SYNC_PTR ioctl. There, we may receive the same appl_ptr
value, and in such a case, calling ack is obviously superfluous.

This patch adds the check of the given appl_ptr value, and returns
immediately if it's no real update.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: add 'applptr' event of tracepoint

In design of ALSA PCM core, status and control data for runtime of ALSA
PCM substream are shared between kernel/user spaces by page frame
mapping with read-only attribute. Both of hardware-side and
application-side position on PCM buffer are maintained as a part of
the status data. In a view of ALSA PCM application, these two positions
can be updated by executing ioctl(2) with some commands.

There's an event of tracepoint for hardware-side position; 'hwptr'.
On the other hand, no events for application-side position. This commit
adds a new event for this purpose; 'applptr'. When the application-side
position is changed in kernel space, this event is probed with useful
information for developers.

I note that the event is not probed for all of ALSA PCM applications, When
applications are written by read/write programming scenario, the event is
surely probed. The applications execute ioctl(2) with
SNDRV_PCM_IOCTL_[READ|WRITE][N/I]_FRAMES to read/write any PCM frame, then
ALSA PCM core updates the application-side position in kernel land.
However, when applications are written by mmap programming scenario, if
maintaining the application side position in kernel space accurately,
applications should voluntarily execute ioctl(2) with
SNDRV_PCM_IOCTL_SYNC_PTR to commit the number of handled PCM frames. If
not voluntarily, the application-side position is not changed, thus the
added event is not probed.

There's a loophole, using architectures to which ALSA PCM core judges
non cache coherent. In this case, the status and control data is not mapped
into processe's VMA for any applications. Userland library, alsa-lib, is
programmed for this case. It executes ioctl(2) with
SNDRV_PCM_IOCTL_SYNC_PTR command every time to requiring the status and
control data.

ARM is such an architecture. Below is an example with serial sound interface
(ssi) on i.mx6 quad core SoC. I use v4.1 kernel released by fsl-community
with patches from VIA Tech. Inc. for VAB820, and my backport patches for
relevant features for this patchset. I use Ubuntu 17.04 from
ports.ubuntu.com as user land for armhf architecture.

$ aplay -v -M -D hw:imx6vab820sgtl5,0 /dev/urandom -f S16_LE -r 48000 --period-size=128 --buffer-size=256
Playing raw data '/dev/urandom' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono
Hardware PCM card 0 'imx6-vab820-sgtl5000' device 0 subdevice 0
Its setup is:
stream : PLAYBACK
access : MMAP_INTERLEAVED
format : S16_LE
subformat : STD
channels : 1
rate : 48000
exact rate : 48000 (48000/1)
msbits : 16
buffer_size : 256
period_size : 128
period_time : 2666
tstamp_mode : NONE
tstamp_type : MONOTONIC
period_step : 1
avail_min : 128
period_event : 0
start_threshold : 256
stop_threshold : 256
silence_threshold: 0
silence_size : 0
boundary : 1073741824
appl_ptr : 0
hw_ptr : 0
mmap_area[0] = 0x76f98000,0,16 (16)

$ trace-cmd record -e snd_pcm:hwptr -e snd_pcm:applptr
$ trace-cmd report
...
60.208495: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=0, period=128, buf=256
60.208633: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=0, period=128, buf=256
60.210022: hwptr: pcmC0D0p/sub0: IRQ: pos=128, old=1536, base=1536, period=128, buf=256
60.210202: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256
60.210344: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1664, base=1536, period=128, buf=256
60.210348: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256
60.210486: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256
60.210626: applptr: pcmC0D0p/sub0: prev=1792, curr=1920, avail=0, period=128, buf=256
60.211002: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256
60.211142: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1664, base=1536, period=128, buf=256
60.211146: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256
60.211287: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256
60.212690: hwptr: pcmC0D0p/sub0: IRQ: pos=0, old=1664, base=1536, period=128, buf=256
60.212866: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256
60.212999: hwptr: pcmC0D0p/sub0: POS: pos=0, old=1792, base=1792, period=128, buf=256
60.213003: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256
60.213135: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256
60.213276: applptr: pcmC0D0p/sub0: prev=1920, curr=2048, avail=0, period=128, buf=256
60.213654: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256
60.213796: hwptr: pcmC0D0p/sub0: POS: pos=0, old=1792, base=1792, period=128, buf=256
60.213800: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256
60.213937: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256
60.215356: hwptr: pcmC0D0p/sub0: IRQ: pos=128, old=1792, base=1792, period=128, buf=256
60.215542: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256
60.215679: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1920, base=1792, period=128, buf=256
60.215683: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256
60.215813: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256
60.215947: applptr: pcmC0D0p/sub0: prev=2048, curr=2176, avail=0, period=128, buf=256
...

We can surely see 'applptr' event is probed even if the application run
for mmap programming scenario ('-M' option and 'hw' plugin). Below is a
result of strace:

02:44:15.886382 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.887203 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}])
02:44:15.887471 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.887637 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.887805 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.887969 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.888132 read(3, "..."..., 256) = 256
02:44:15.889040 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.889221 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.889431 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.889606 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}])
02:44:15.889833 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.889998 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.890164 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.891048 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.891228 read(3, "..."..., 256) = 256
02:44:15.891497 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.891661 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.891829 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.891991 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}])
02:44:15.893007 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0

We can see 7 calls of ioctl(2) with SNDRV_PCM_IOCTL_SYNC_PTR per loop with
call of poll(2). 128 PCM frames are transferred per loop of one poll(2),
because the PCM substream is configured with S16_LE format and 1 channel
(2 byte * 1 * 128 = 256 bytes). This equals to the size of period of PCM
buffer. Comparing to the probed data, one of the 7 calls of ioctl(2) is
actually used to commit the number of copied PCM frames to kernel space.
The other calls are just used to check runtime status of PCM substream;
e.g. XRUN.

The tracepoint event is useful to investigate this case. I note that below
modules are related to the above sample.

* snd-soc-dummy.ko
* snd-soc-imx-sgtl5000.ko
* snd-soc-fsl-ssi.ko
* snd-soc-imx-pcm-dma.ko
* snd-soc-sgtl5000.ko

My additional note is lock acquisition. The event is probed under acquiring
PCM stream lock. This means that calculation in the event is free from
any hardware events.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: unify codes to operate application-side position on PCM buffer

In a series of recent work, ALSA PCM core got some arrangements to handle
application-side position on PCM buffer. However, relevant codes still
disperse to two translation units

This commit unifies these codes into a helper function.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: localize snd_pcm_hw_params_choose()

As of v4.12, snd_pcm_hw_params_choose() is just called in a process
context of ioctl(2) with SNDRV_PCM_IOCTL_HW_PARAMS. The function locates
in a different file, which has no tracepoints.

This commit moves the function to a file with the tracepoints for later
commit.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Direct in-kernel read/write support

Now all materials are ready, let's allow the direct in-kernel
read/write, i.e. a kernel-space buffer is passed for read or write,
instead of the normal user-space buffer. This feature is used by OSS
layer and UAC1 driver, for example.

The __snd_pcm_lib_xfer() takes in_kernel argument that indicates the
in-kernel buffer copy. When this flag is set, another transfer code
is used. It's either via copy_kernel PCM ops or the normal memcpy(),
depending on the driver setup.

As external API, snd_pcm_kernel_read(), *_write() and other variants
are provided.

That's all. This support is really simple because of the code
refactoring until now.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Simplify snd_pcm_playback_silence()

Use the existing silence helper codes for simplification.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Unify read/write loop

Both __snd_pcm_lib_read() and __snd_pcm_write() functions have almost
the same code to loop over samples. For simplification, this patch
unifies both as the single helper, __snd_pcm_lib_xfer().

Other than that, there should be no functional change by this patch.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: More unification of PCM transfer codes

This patch proceeds more abstraction of PCM read/write loop codes.

For both interleaved and non-interleaved transfers, the same copy or
silence transfer code (which is defined as pcm_transfer_f) is used
now. This became possible since we switched to byte size to copy_*
and fill_silence ops argument instead of frames.

And, for both read and write, we can use the same copy function (which
is defined as pcm_copy_f), just depending on whether interleaved or
non-interleaved mode.

The transfer function is determined at the beginning of the loop,
depending on whether the driver gives the specific copy ops or it's
the standard read/write.

Another bonus by this change is that we now guarantee the silencing
behavior when NULL buffer is passed to write helpers. It'll simplify
some codes later.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Call directly the common read/write helpers

Make snd_pcm_lib_read() and *_write() static inline functions that
call the common helper functions directly. This reduces a slight
amount of codes, and at the same time, it's a preparation for the
further cleanups / fixes.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Shuffle codes

Just shuffle the codes, without any change otherwise.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Check PCM state by a common helper function

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Drop the old copy and silence ops

Now that all users of old copy and silence ops have been converted to
the new PCM ops, the old stuff can be retired and go away.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Introduce copy_user, copy_kernel and fill_silence ops

For supporting the explicit in-kernel copy of PCM buffer data, and
also for further code refactoring, three new PCM ops, copy_user,
copy_kernel and fill_silence, are introduced. The old copy and
silence ops will be deprecated and removed later once when all callers
are converted.

The copy_kernel ops is the new one, and it's supposed to transfer the
PCM data from the given kernel buffer to the hardware ring-buffer (or
vice-versa depending on the stream direction), while the copy_user ops
is equivalent with the former copy ops, to transfer the data from the
user-space buffer.

The major difference of the new copy_* and fill_silence ops from the
previous ops is that the new ops take bytes instead of frames for size
and position arguments. It has two merits: first, it allows the
callback implementation often simpler (just call directly memcpy() &
co), and second, it may unify the implementations of both interleaved
and non-interleaved cases, as we'll see in the later patch.

As of this stage, copy_kernel ops isn't referred yet, but only
copy_user is used.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: add local header file for snd-pcm module

Several files are used to construct PCM core module, a.k.a snd-pcm.
Although available APIs are described in 'include/sound/pcm.h', some of
them are not exported as symbols in kernel space. Such APIs are just for
module local usage.

This commit adds module local header file and move some function prototypes
into it so that scopes of them are controlled properly and developers
get no confusion from unavailable symbols.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: constify function local and read-only table

In a function snd_pcm_hw_params_choose(), target parameters are arranged
into a table. Though each entry of this table is read-only, they don't
have const qualifier.

This commit adds the qualifier.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: use helper function to refer parameter as read-only

ALSA pcm core has hw_param_interval_c() to pick up parameter with const
qualifier for safe programming.

This commit applies it to the cases.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>

Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

ALSA: pcm: Bail out when chmap is already present

When snd_pcm_add_chmap_ctls() is called to the PCM stream to which a
chmap has been already assigned, it returns as an error due to the
conflicting snd_ctl_add() result. However, this also clears the
already assigned chmap_kctl field via pcm_chmap_ctl_private_free(),
and becomes inconsistent in the later operation.

This patch adds the check of the conflicting chmap kctl before
actually trying to allocate / assign. The check failure is treated as
a kernel warning, as the double call of snd_pcm_add_chmap_ctls() is
basically a driver bug and having the stack trace would help
developers to figure out the bad code path.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm : Call kill_fasync() in stream lock

Currently kill_fasync() is called outside the stream lock in
snd_pcm_period_elapsed(). This is potentially racy, since the stream
may get released even during the irq handler is running. Although
snd_pcm_release_substream() calls snd_pcm_drop(), this doesn't
guarantee that the irq handler finishes, thus the kill_fasync() call
outside the stream spin lock may be invoked after the substream is
detached, as recently reported by KASAN.

As a quick workaround, move kill_fasync() call inside the stream
lock. The fasync is rarely used interface, so this shouldn't have a
big impact from the performance POV.

Ideally, we should implement some sync mechanism for the proper finish
of stream and irq handler. But this oneliner should suffice for most
cases, so far.

Reported-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Avoid "BUG:" string for warnings again

The commit [d507941beb1e: ALSA: pcm: Correct PCM BUG error message]
made the warning prefix back to "BUG:" due to its previous wrong
prefix. But a kernel message containing "BUG:" seems taken as an Oops
message wrongly by some brain-dead daemons, and it annoys users in the
end. Instead of teaching daemons, change the string again to a more
reasonable one.

Fixes: 507941beb1e ('ALSA: pcm: Correct PCM BUG error message')
Cc: <stable@vger.kernel.org> # v3.19+
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Constify ratden/ratnum constraints

The ALSA core does not modify the constraints provided by a driver. Most
constraint helper functions already take a const pointer to the constraint
description, the exception at the moment being the ratden and ratnum
constraints. Make those const as well, this allows a driver to declare them
as const.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Remove transfer_ack_{begin,end} callbacks from struct snd_pcm_runtime

While there is nothing wrong with the transfer_ack_begin and
transfer_ack_end callbacks per-se, the last documented user was part of the
alsa-driver 0.5.12a package, which was released 14 years ago and even
predates the upstream integration of the ALSA core and has subsequently
been superseded by newer alsa-driver releases.

This seems to indicate that there is no need for having these callbacks and
they are just cruft that can be removed.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: timer: add config item to export PCM timer disabling for expert

PCM timer is not always used. For embedded device, we need an interface
to disable it when it is not needed, to shrink the kernel size and
memory footprint, here add CONFIG_SND_PCM_TIMER for it.

When both CONFIG_SND_PCM_TIMER and CONFIG_SND_TIMER is unselected,
about 25KB saving bonus we can get.

Please be noted that when disabled, those stubs who using pcm timer
(e.g. dmix, dsnoop & co) may work incorrectlly.

Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jie Yang <yang.jie@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Modify double acknowledged interrupts check condition

Currently in snd_pcm_update_hw_ptr0 during interrupt,
we consider there were double acknowledged interrupts when:
1. HW reported pointer is smaller than expected, and
2. Time from last update time (hdelta) is over half a buffer time.

However, when HW reported pointer is only a few bytes smaller than
expected, and when hdelta is just a little larger than half a buffer time
(e.g. ping-pong buffer), it wrongly treats this IRQ as double acknowledged.

The condition #2 uses jiffies, but jiffies is not high resolution
since it is integer. We should consider jiffies inaccuracy.

Signed-off-by: Koro Chen <koro.chen@mediatek.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: core: add .get_time_info

Introduce more generic .get_time_info to retrieve
system timestamp and audio timestamp in single routine.
Backwards compatibility is preserved with same functionality
as with .wall_clock method (to be removed in following commits
to avoid breaking git bisect)

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Add snd_interval_ranges() and snd_pcm_hw_constraint_ranges()

Add helper functions to allow drivers to specify several disjoint
ranges for a variable. In particular, there is a codec (PCM512x) that
has a hole in its supported range of rates, due to PLL and divider
restrictions.

This is like snd_pcm_hw_constraint_list(), but for ranges instead of
points.

Signed-off-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

ALSA: Add support for wildcard msbits constraints

Currently the msbits constraints requires to specify a specific sample
format width for which the constraint should be applied. But often the
number of most significant bits is not sample format specific, but rather a
absolute limit. E.g. the PCM interface might accept 32-bit and 24-bit
samples, but the DAC has a 16-bit resolution and throws away the LSBs. In
this case for both 32-bit and 24-bit format msbits should be set to 16. This
patch extends snd_pcm_hw_constraint_msbits() so that a wildcard constraint
can be setup that is applied for all formats with a sample width larger than
the specified msbits. Choosing the wildcard constraint is done by setting
the sample width parameter of the function to 0.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Fix handling of multiple msbits constraints on the same runtime

If the sound card is made up of discrete components, each with their own
driver (e.g. like in the ASoC case), we might end up with multiple msbits
constraint rules installed. Currently this will result in msbits being set
to whatever the last rule set it to.

This patch updates the behavior of the rule to choose the minimum (other
than zero) of all the installed rules.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Replace PCM hwptr tracking with tracepoints

ALSA PCM core has a mechanism tracking the PCM hwptr updates for
analyzing XRUNs. But its log is limited (up to 10) and its log output
is a kernel message, which is hard to handle.

In this patch, the hwptr logging is moved to the tracing
infrastructure instead of its own. Not only the hwptr updates but
also XRUN and hwptr errors are recorded on the trace log, so that user
can see such events at the exact timing.

The new "snd_pcm" entry will appear in the tracing events:
# ls -F /sys/kernel/debug/tracing/events/snd_pcm
enable filter hw_ptr_error/ hwptr/ xrun/

The hwptr is for the regular hwptr update events. An event trace
looks like:

aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384

"POS" shows the hwptr update by the explicit position update call and
"IRQ" means the hwptr update by the interrupt,
i.e. snd_pcm_period_elapsed() call. The "pos" is the passed
ring-buffer offset by the caller, "old" is the previous hwptr, "base"
is the hwptr base position, "period" and "buf" are period- and
buffer-size of the target PCM substream.
(Note that the hwptr position displayed here isn't the ring-buffer
offset. It increments up to the PCM position boundary.)

The XRUN event appears similarly, but without "pos" field.
The hwptr error events appear with the PCM identifier and its reason
string, such as "Lost interrupt?".

The XRUN and hwptr error reports on kernel message are still left, can
be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5
and 6 bits of xrun_debug proc are dropped by this patch. Also, along
with the change, the message strings have been reformatted to be a bit
more consistent.

Last but not least, the hwptr reporting is enabled only when
CONFIG_SND_PCM_XRUN_DEBUG is set.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Correct PCM BUG error message

While converting to dev_*(), the message showing the invalid PCM
position was wrongly tagged as if an XRUN although it's actually a
BUG. This patch corrects the message again.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: fix fifo_size frame calculation

The calculated frame size was wrong because snd_pcm_format_physical_width()
actually returns the number of bits, not bytes.

Use snd_pcm_format_size() instead, which not only returns bytes, but also
simplifies the calculation.

Fixes: 8bea869c5e56 ("ALSA: PCM midlevel: improve fifo_size handling")
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: snd_interval_step: fix changes of open intervals

Changing an interval boundary to a multiple of the step size makes that
boundary exact.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: snd_interval_step: drop the min parameter

The min parameter was not used by any caller. And if it were used,
underflows in the calculations could lead to incorrect results.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: 'BUG:' message unnecessarily triggers kerneloops

BugLink: http://bugs.launchpad.net/bugs/1305480

The kerneloops-daemon scans dmesg for common crash signatures, among
which is 'BUG:'. The message emitted by the PCM library is really a
warning, so the most expedient thing to do seems to be to change the
string.

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Export snd_pcm_constraint_mask64()

Allow modules to use it, fixing a build failure when the newly added
ADAU1977 driver is built as a module.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Mark Brown <broonie@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Use standard printk helpers

Use dev_err() & co as much as possible. If not available (no device
assigned at the calling point), use pr_xxx() helpers instead.

For simplicity, introduce new helpers for pcm stream, pcm_err(), etc.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Add SNDRV_PCM_STATE_PAUSED case in wait_for_avail function

When the process is sleeping at the SNDRV_PCM_STATE_PAUSED
state from the wait_for_avail function, the sleep process will be woken by
timeout(10 seconds). Even if the sleep process wake up by timeout, by this
patch, the process will continue with sleep and wait for the other state.

Signed-off-by: JongHo Kim <furmuwon@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Use snd_printd_ratelimit()

The use of snd_printd_ratelimit() supresses superfluous output from
printk_ratelimit() when CONFIG_SND_DEBUG is not defined. For example,

[ 43.753692] snd_pcm_update_hw_ptr0: 26 callbacks suppressed
[ 48.822131] snd_pcm_update_hw_ptr0: 25 callbacks suppressed
[ 53.894953] snd_pcm_update_hw_ptr0: 25 callbacks suppressed
[ 58.997761] snd_pcm_update_hw_ptr0: 25 callbacks suppressed
[ 64.100952] snd_pcm_update_hw_ptr0: 25 callbacks suppressed

fills the log even when no debug output is actually produced.

Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Constify the snd_pcm_substream struct ops field

The ops field of the snd_pcm_substream struct is never modified inside the ALSA
core. Making it const allows drivers to declare their snd_pcm_ops struct as
const.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: add/change some comments describing function return values

script/kernel-doc reports the following type of warnings (when run in verbose
mode):

Warning(sound/core/init.c:152): No description found for return value of
'snd_card_create'

To fix that:
- add missing descriptions of function return values
- use "Return:" sections to describe those return values

Along the way:
- complete some descriptions
- fix some typos

Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: core: add hooks for audio timestamps

ALSA did not provide any direct means to infer the audio time for A/V
sync and system/audio time correlations (eg. PulseAudio).
Applications had to track the number of samples read/written and
add/subtract the number of samples queued in the ring buffer. This
accounting led to small errors, typically several samples, due to the
two-step process. Computing the audio time in the kernel is more
direct, as all the information is available in the same routines.

Also add new .audio_wallclock routine to enable fine-grain synchronization
between monotonic system time and audio hardware time.
Using the wallclock, if supported in hardware, allows for a
much better sub-microsecond precision and a common drift tracking for
all devices sharing the same wall clock (master clock).

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: core: keep track of boundary wrap-around

Keep track of boundary crossing when hw_ptr
exceeds boundary limit and wraps-around. This
will help keep track of total number
of frames played/received at the kernel level

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Fix leftover chmap UNKNOWN -> MONO conversions

A few files have been slipped from the previous commit to add MONO
channel type.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Use UNKNOWN chmap for mono streams

In general, mono streams have no dedicated speaker assignment, thus
they should be rather marked as UNKNOWN position.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Remove VOLATILE flag from chmap ctls

The VOLATILE flag was added to control elements by
snd_pcm_add_chmap_ctls() just because I didn't want to have a
side-effect of "alsactl restore". But now the set operation doesn't
allow to change the value unless the PCM stream is in PREAPRED state,
there is no reason to keep this flag. Let's rip it off.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: PCM: channel mapping API implementation

This patch implements the basic data types for the standard channel
mapping API handling.

- The definitions of the channel positions and the new TLV types are
added in sound/asound.h and sound/tlv.h, so that they can be
referred from user-space.

- Introduced a new helper function snd_pcm_add_chmap_ctls() to create
control elements representing the channel maps for each PCM
(sub)stream.

- Some standard pre-defined channel maps are provided for
convenience.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Make constraints lists const

They aren't modified by the core so the drivers can declare them const.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: core: group read of pointer, tstamp and jiffies

Group read of hw_ptr, tstamp and jiffies in a sequence
for better correlation. Previous code took timestamp at the
end, which could introduce delays between audio time and
system time.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Optimize the call of snd_pcm_update_hw_ptr() in read/write loop

In the PCM read/write loop, the driver calls snd_pcm_update_hw_ptr()
at each time at the beginning of the loop. Russell King reported that
this hogs CPU significantly.

The current code assumes that the pointer callback is very fast and
cheap, also not too much fine grained. It's not true in all cases.
When the pointer advances short samples while the read/write copy has
been performed, the driver updates the hw_ptr and gets avail > 0
again. Then it tries to read/write these small chunks. This repeats
until the avail really gets to zero.

For avoiding this situation, a simple workaround is to call
snd_pcm_update_hw_ptr() only once at starting the loop, assuming that
the read/write copy is performed fast enough. If the available count
becomes short, it goes to snd_pcm_wait_avail() anyway, and this
processes right.

Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: Constify the list in snd_pcm_hw_constraint_list

Allows the constraint lists to be declared const by drivers which seems
reasonable; there's plenty of other constification we could do if we were
being complete but this was easy and quick.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound: Add export.h for THIS_MODULE/EXPORT_SYMBOL where needed

These aren't modules, but they do make use of these macros, so
they will need export.h to get that definition. Previously,
they got it via the implicit module.h inclusion.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

ALSA: pcm: add snd_pcm_hw_rule_noresample()

Add a helper function to allow drivers to disable hardware resampling
when the application has specified the SNDRV_PCM_HW_PARAMS_NORESAMPLE
flag.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - fix race condition in wait_for_avail()

wait_for_avail() in pcm_lib.c has a race in it (observed in practice by an
Intel validation group).

The function is supposed to return once space in the buffer has become
available, or if some timeout happens. The entity that creates space (irq
handler of sound driver and some such) will do a wake up on a waitqueue
that this function registers for.

However there are two races in the existing code

1) If space became available between the caller noticing there was no
space and this function actually sleeping, the wakeup is missed and the
timeout condition will happen instead

2) If a wakeup happened but not sufficient space became available, the
code will loop again and wait for more space. However, if the second
wake comes in prior to hitting the schedule_timeout_interruptible(), it
will be missed, and potentially you'll wait out until the timeout
happens.

The fix consists of using more careful setting of the current state (so
that if a wakeup happens in the main loop window, the schedule_timeout()
falls through) and by checking for available space prior to going into the
schedule_timeout() loop, but after being on the waitqueue and having the
state set to interruptible.

[tiwai: the following changes have been added to Arjan's original patch:
- merged akpm's fix for waitqueue adding order into a single patch
- reduction of duplicated code of avail check
]

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Make snd_pcm_debug_name usable outside pcm_lib

Formatting a PCM name is useful for module debug too.
Add snd_prefix when making function public.

[minor coding-style fixes by tiwai]

Signed-off-by: Eliot Blennerhassett <eblennerhassett@audioscience.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: PCM - Don't check DMA time-out too shortly

When the PCM period size is set larger than 10 seconds, currently the
PCM core may abort the operation with DMA-error due to the fixed timeout
for 10 seconds. A similar problem is seen in the drain operation that
has a fixed timeout of 10 seconds, too.

This patch fixes the timeout length depending on the period size and
rate, also including the consideration of no_period_wakeup flag.

Reported-by: Raymond Yau <superquad.vortex2@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: sound, core, pcm_lib: fix xrun_log

The xrun_log function was augmented with the in_interrupt parameter whereas the
empty macro definition used when xrun logging is disabled was not.

Add a third parameter to the empty macro definition so as to not cause compiler
errors when xrun logging (CONFIG_SND_PCM_XRUN_DEBUG) is disabled.

Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: sound, core, pcm_lib: xrun_log: log also in_interrupt

When debugging pcm drivers I found the "period" or "hw" prefix printed
by either XRUN_DEBUG_PERIODUPDATE or XRUN_DEBUG_PERIODUPDATE events,
respectively to be very useful is observing the interplay between
interrupt-context updates and syscall-context updates.

Similarly, when debugging overruns with XRUN_DEBUG_LOG it is useful to
see the context of the last 10 positions.

Add an in_interrupt member to hwptr_log_entry which stores the value of
the in_interrupt parameter of snd_pcm_update_hw_ptr0 when the log entry
is created. Print a "[Q]" prefix when dumping the log entries if
in_interrupt was true.

Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: fix infinite loop in snd_pcm_update_hw_ptr0()

When period interrupts are disabled, snd_pcm_update_hw_ptr0() compares
the current time against the time estimated for the current hardware
pointer to detect xruns. The somewhat fuzzy threshold in the while loop
makes it possible that hdelta becomes negative; the comparison being
done with unsigned types then makes the loop go through the entire 263
negative range, and, depending on the value, never reach an unsigned
value that is small enough to stop the loop. Doing this with interrupts
disabled results in the machine locking up.

To prevent this, ensure that the loop condition uses signed types for
both operands so that the comparison is correctly done.

Many thanks to Kelly Anderson for debugging this.

Reported-by: Nix <nix@esperi.org.uk>
Reported-by: "Christopher K." <c.krooss@googlemail.com>
Reported-and-tested-by: Kelly Anderson <kelly@silka.with-linux.com>
Signed-off-by: Kelly Anderson <kelly@silka.with-linux.com>
[cl: remove unneeded casts; use a temp variable]
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: 2.6.38 <stable@kernel.org>

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: remember to always call va_end() on stuff that we va_start()

The Coverity checker spotted that we do not always remember to call
va_end() on 'args' in failure paths in snd_pcm_hw_rule_add().
Here's a patch to fix that up (compile tested only) - it also removes
some annoying trailing whitespace that caught my eye while I was in the
area..

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: optimize xrun detection in no-period-wakeup mode

Add a lightweight condition on top of the xrun checking so that we can
avoid the division when the application is calling the update function
often enough.

Suggested-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: detect xruns in no-period-wakeup mode

When period wakeups are disabled, successive calls to the pointer update
function do not have a maximum allowed distance, so xruns cannot be
detected with the pointer value only.

To detect xruns, compare the actually elapsed time with the time that
should have theoretically elapsed since the last update. When the
hardware pointer has wrapped around due to an xrun, the actually elapsed
time will be too big by about hw_ptr_buffer_jiffies.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: support for period wakeup disabling

This patch allows to disable period interrupts which are
not needed when the application relies on a system timer
to wake-up and refill the ring buffer. The behavior of
the driver is left unchanged, and interrupts are only
disabled if the application requests this configuration.
The behavior in case of underruns is slightly different,
instead of being detected during the period interrupts the
underruns are detected when the application calls
snd_pcm_update_avail, which in turns forces a refresh of the
hw pointer and shows the buffer is empty.

More specifically this patch makes a lot of sense when
PulseAudio relies on timer-based scheduling to access audio
devices such as HDAudio or Intel SST. Disabling interrupts
removes two unwanted wake-ups due to period elapsed events
in low-power playback modes. It also simplifies PulseAudio
voice modules used for speech calls.

To quote Lennart "This patch looks very interesting and
desirable. This is something have long been waiting for."

Support for this in hardware drivers is optional.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@intel.com>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: sound/core/pcm_lib.c: Remove unnecessary semicolons

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm midlevel code - add time check for double interrupt acknowledge

The current code in pcm_lib.c do all checks using only the position
in the ring buffer. Unfortunately, where the interrupts gets delayed or
merged into one, we need another timing source to check when the
buffer size boundary overlaps to avoid the wrong updating of the
ring buffer pointers.

This code uses jiffies to check the right time window without any
performance impact.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: pcm midlevel code - add time check for double interrupt acknowledge

The current code in pcm_lib.c do all checks using only the position
in the ring buffer. Unfortunately, where the interrupts gets delayed or
merged into one, we need another timing source to check when the
buffer size boundary overlaps to avoid the wrong updating of the
ring buffer pointers.

This code uses jiffies to check the right time window without any
performance impact.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm core - add a safe check to the silence filling function

In situation when appl_ptr is far greater then hw_ptr, the hw_avail value
can be greater than buffer_size. Check for this.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: pcm_lib: avoid timing jitter in snd_pcm_read/write()

When using poll() to wait for the next period -- or avail_min samples --
one gets a consistent delay for each system call that is usually just a
little short of the selected period time. However, When using
snd_pcm_read/write(), one gets a jittery delay that alternates between
less than a millisecond and approximately two period times. This is
caused by snd_pcm_lib_{read,write}1() transferring any available samples
to the user's buffer and adjusting the application pointer prior to
sleeping to the end of the current period. When the next period
interrupt occurs, there is then less than avail_min samples remaining to
be transferred in the period, so we end up sleeping until a second
period occurs.

This is solved by using runtime->twake as the number of samples needed
for a wakeup in addition to selecting the proper wait queue to wake in
snd_pcm_update_state(). This requires twake to be non-zero when used
by snd_pcm_lib_{read,write}1() even if avail_min is zero.

Signed-off-by: Dave Dillow <dave@thedillows.org>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: pcm: fix delta calculation at boundary wraparound

In the cleanup of the hw_ptr update functions in 2.6.33, the calculation
of the delta value was changed to use the modulo operator to protect
against a negative difference due to the pointer wrapping around at the
boundary.

However, the ptr variables are unsigned, so a negative difference would
result in the two complement's value which has no relation to the actual
difference relative to the boundary; the result is typically some value
near LONG_MAX-boundary. Furthermore, even if the modulo operation would
be done with signed types, the result of a negative dividend could be
negative.

The invalid delta value is then caught by the following checks, but this
means that the pointer update is ignored.

To fix this, use a range check as in the other pointer calculations.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: fix the fix of the runtime->boundary calculation

Commit 7910b4a1db63fefc3d291853d33c34c5b6352e8e in 2.6.34 changed the
runtime->boundary calculation to make this value a multiple of both the
buffer_size and the period_size, because the latter is assumed by the
runtime->hw_ptr_interrupt calculation.

However, due to the lack of a ioctl that could read the software
parameters before they are set, the kernel requires that alsa-lib
calculates the boundary value, too. The changed algorithm leads to
a different boundary value used by alsa-lib, which makes, e.g., mplayer
fail to play a 44.1 kHz file because the silence_size parameter is now
invalid; bug report:
<https://bugtrack.alsa-project.org/alsa-bug/view.php?id=5015>.

This patch reverts the change to the boundary calculation, and instead
fixes the hw_ptr_interrupt calculation to be period-aligned regardless
of the boundary value.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm_lib - fix xrun functionality

The commit 4d96eb255c53ab5e39b37fd4d484ea3dc39ab456 broke the interrupt
time xrun functionality (stream stop etc.) if the CONFIG_SND_PCM_XRUN_DEBUG
is not set. This is because the xrun() is null defined without it.

Fix this by letting the function xrun() to be always defined as it was
before.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm_lib - return back hw_ptr_interrupt

Clemens Ladisch noted for hw_ptr_removal in "cleanup & merge hw_ptr
update functions" commit:

"It is possible for the status/delay ioctls to be called when the sound
card's pointer register alreay shows a position at the beginning of the
new period, but immediately before the interrupt is actually executed.
(This happens regularly on a SMP machine with mplayer.) When that
happens, the code thinks that the position must be at least one period
ahead of the current position and drops an entire buffer of data."

Return back the hw_ptr_interrupt variable. The last interrupt pointer
is always computed from the latest hw_ptr instead of tracking it
separately (in this case all hw_ptr checks and modifications might
influence also hw_ptr_interrupt and it is difficult to keep it
consistent).

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: pcm_core: Fix wake_up() optimization

This change fixes the "ALSA: pcm_lib - optimize wake_up() calls for PCM I/O"
commit. New sleeping queue is introduced to separate user space and kernel
space wake_ups. runtime->nowake is renamed to twake (transfer wake).

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: pcm_lib - fix wrong delta print for jiffies check

The previous jiffies delta was 0 in all cases. Use hw_ptr variable to
store and print original value.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: pcm_lib: fix "something must be really wrong" condition

When runtime->periods == 1 or when pointer crosses end of ring buffer,
the delta might be greater than buffer_size.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: pcm_lib - optimize wake_up() calls for PCM I/O

As noted by pl bossart <bossart.nospam@gmail.com>, the PCM I/O routines
(snd_pcm_lib_write1, snd_pcm_lib_read1) should block wake_up() calls
until all samples are not processed.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: pcm_lib - cleanup & merge hw_ptr update functions

Do general cleanup in snd_pcm_update_hw_ptr*() routines and merge them.
The main change is hw_ptr_interrupt variable removal to simplify code
logic. This variable can be computed directly from hw_ptr.

Ensure that updated hw_ptr is not lower than previous one (it was possible
with old code in some obscure situations when interrupt was delayed or
the lowlevel driver returns wrong ring buffer position value).

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: pcm_lib - add possibility to log last 10 DMA ring buffer positions

In some debug cases, it might be usefull to see previous ring buffer
positions to determine position problems from the lowlevel drivers.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: pcm_lib.c - convert second xrun_debug() parameter to use defines

To increase code readability, convert send xrun_debug() argument to
use defines.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: refine rate selection in snd_interval_ratnum()

Refine the rate selection by choosing the rate
closer to the requested one in case of selecting
single frequency. Previously, the higher rate was
always selected.

Also, fix problem with the best_diff unsigned int
value wrapping (turning negative).

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: fix incorrect rounding direction in snd_interval_ratnum()

The direction of rounding is incorrect in the snd_interval_ratnum()
It was detected with following parameters (sb8 driver playing
8kHz stereo file):
- num is always 1000000
- requested frequency rate is from 7999 to 7999 (single frequency)

The first loop calculates div_down(num, freq->min) which is 125.
Thus, a frequency range's minimum value is 1000000 / 125 = 8000 Hz.
The second loop calculates div_up(num, freq->max) which is 126
The frequency range's maximum value is 1000000 / 126 = 7936 Hz.
The range maximum is lower than the range minimum so the function
fails due to empty result range.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound: pcm_lib: fix unsorted list constraint handling

snd_interval_list() expected a sorted list but did not document this, so
there are drivers that give it an unsorted list. To fix this, change
the algorithm to work with any list.

This fixes the "Slave PCM not usable" error with USB devices that have
multiple alternate settings with sample rates in decreasing order, such
as the Philips Askey VC010 WebCam.

http://bugzilla.kernel.org/show_bug.cgi?id=14028

Reported-and-tested-by: Andrzej <adkadk@gmail.com>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Fix drain behavior in non-blocking mode

The current PCM core has the following problems regarding PCM draining
in non-blocking mode:

- the current f_flags isn't checked in snd_pcm_drain(), thus changing
the mode dynamically via snd_pcm_nonblock() after open doesn't work.
- calling drain in non-blocking mode just return -EAGAIN error, but
doesn't provide any way to sync with draining.

This patch fixes these issues.
- check file->f_flags in snd_pcm_drain() properly
- when O_NONBLOCK is set, PCM core sets the stream(s) to DRAIN state
but quits ioctl immediately without waiting the whole drain; the
caller can sync the drain manually via poll()

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Fix hwptr buffer-size overlap bug

The fix 79452f0a28aa5a40522c487b42a5fc423647ad98 introduced another
bug due to the missing offset for the overlapped hwptr.
When the hwptr goes back to zero, the delta value has to be corrected
with the buffer size. Otherwise this causes looping sounds.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Fix warnings in debug loggings

Add proper cast.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Add logging of hwptr updates and interrupt updates

Added the logging functionality to xrun_debug to record the hwptr
updates via snd_pcm_update_hw_ptr() and snd_pcm_update_hwptr_interrupt(),
corresponding to 16 and 8, respectively.

For example,
# echo 9 > /proc/asound/card0/pcm0p/xrun_debug
will record the position and other parameters at each period interrupt
together with the normal XRUN debugging.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Fix regressions with VMware

VMware tends to report PCM positions and period updates at utterly
wrong timing. This screws up the recent PCM core code that tries
to correct the position based on the irq timing.

Now, when a backward irq position is detected, skip the update
instead of rebasing. (This is almost the old behavior before
2.6.30.)

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - A helper function to compose PCM stream name for debug prints

Use a common helper function for the PCM stream name displayed in
XRUN and buffer-pointer debug prints.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Fix update of runtime->hw_ptr_interrupt

The commit 13f040f9e55d41e92e485389123654971e03b819 made another
regression, the missing update of runtime->hw_ptr_interrupt.
Since this field is only checked in snd_pcmupdate__hw_ptr_interrupt(),
not in snd_pcm_update_hw_ptr(), it must be updated before the hw_ptr
change check.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Fix a typo in hw_ptr update check

Fix a typo in the commit 13f040f9e55d41e92e485389123654971e03b819
ALSA: PCM midlevel: Do not update hw_ptr_jiffies when hw_ptr is not changed
which causes obvious problems with PA.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Clean up 64bit division functions

Replace the house-made div64_32() with the standard div_u64*() functions.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: PCM midlevel: lower jiffies check margin using runtime->delay value

When hardware has large FIFO, it is necessary to lower jiffies margin
by count of queued samples.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: PCM midlevel: Do not update hw_ptr_jiffies when hw_ptr is not changed

Some hardware might have bigger FIFOs and DMA pointer value will be updated
in large chunks. Do not update hw_ptr_jiffies and position timestamp when
hw_ptr value was not changed.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: PCM midlevel: introduce mask for xrun_debug() macro

For debugging purposes, it is better to separate actions.

Bit-values:

1: show bad PCM ring buffer pointer
2: show also stack (to debug kernel latency issues)
4: check pointer against system jiffies

Example:

5: show bad PCM ring buffer pointer and do jiffies check

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: PCM midlevel: improve fifo_size handling

Move the fifo_size assignment to hw->ioctl callback to allow lowlevel
drivers overwrite the default behaviour.

fifo_size is in frames not bytes as specified in asound.h and alsa-lib's
documentation, but most hardware have fixed byte based FIFOs. Introduce
internal SNDRV_PCM_INFO_FIFO_IN_FRAMES.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Enable PCM hw_ptr_jiffies check only in xrun_debug mode

The PCM hw_ptr jiffies check results sometimes in problems when a
hardware doesn't give smooth hw_ptr updates. So far, au88x0 and some
other drivers appear not working due to this strict check.
However, this check is a nice debug tool, and the capability should be
still kept.

Hence, we disable this check now as default unless the user enables it
by setting the xrun_debug mode to the specific stream via a proc file.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Fix invalid jiffies check after pause

The hw_ptr_jiffies has to be reset properly to avoid the invalid
check of jiffies delta in snd_pcm_update_hw_ptr*() functions.
Especailly this patch fixes the bogus jiffies check after the puase
and resume.

This patch is a modified version of the original patch by Jaroslav.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm core - Avoid jiffies check for devices with BATCH flag

The hardware devices with SNDRV_PCM_INFO_BATCH flag can't give the
precise current position. And such hardwares have often big FIFO
in addition to the ring buffer, and it screws up the jiffies check
in pcm_lib.c.

This patch adds a simple check of info flag so that the driver skips
the jiffies check in snd_pcm_period_elapsed() when BATCH flag is set.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] pcm-midlevel: Add more strict buffer position checks based on jiffies

Some drivers like Intel8x0 or Intel HDA are broken for some hardware variants.
This patch adds more strict buffer position checks based on jiffies when
internal hw_ptr is updated. Enable xrun_debug to see mangling of wrong
positions.

As a side effect, the hw_ptr interrupt update routine might do slightly better
job when many interrupts are lost.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

ALSA: pcm - Safer boundary checks

Make the boundary checks a bit safer.
These caese are rare or theoretically won't happen, but nothing
bad to keep the checks safer...

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Fix delta calculation at boundary overlap

When the hw_ptr_interrupt reaches the boundary, it must check whether
the hw_base was already lapped and corret the delta value appropriately.

Also, rebasing the hw_ptr needs a correction because buffer_size isn't
always aligned to period_size.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Reset invalid position even without debug option

Always reset the invalind hw_ptr position returned by the pointer
callback. The behavior should be consitent independently from the
debug option.

Also, add the printk_ratelimit() check to avoid flooding debug
prints.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - avoid unnecessary inline

Remove unnecessary explicit inlininig of internal functions.
Let compiler optimize.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm - Fix a typo in error messages

Fix a typo in error messages; forgotten after a copy&paste error.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Rewrite hw_ptr updaters

Clean up and improve snd_pcm_update_hw_ptr*() functions.

snd_pcm_update_hw_ptr() tries to detect the unexpected hwptr jumps
more strictly to avoid the position mess-up, which often results in
the bad quality I/O with pulseaudio.

The hw-ptr skip error messages are printed when xrun proc is set to
non-zero.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: kernel docs: fix sound/core/ kernel-doc

Add kernel-doc function short descriptions to sound/core functions that
are missing this short description. Mostly this involves moving some of
the function description onto the @funcname line.

Also correct a few variable names and fix other kernel-doc notation.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: Kill snd_assert() in sound/core/*

Kill snd_assert() in sound/core/*, either removed or replaced with
if () with snd_BUG_ON().

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] PCM interface - rename SNDRV_PCM_TSTAMP_MMAP to SNDRV_PCM_TSTAMP_ENABLE

Change semantics for SNDRV_PCM_TSTAMP_MMAP. Doing timestamping only in
the interrupt handler might cause that hw_ptr is not related to actual
timestamp. With this change, grab timestamp at every hw_ptr update to
have always valid timestamp + ring buffer position pair.
With this change, SNDRV_PCM_TSTAMP_MMAP was renamed to
SNDRV_PCM_TSTAMP_ENABLE. It's no regression (I think).

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] Remove sound/driver.h

This header file exists only for some hacks to adapt alsa-driver
tree. It's useless for building in the kernel. Let's move a few
lines in it to sound/core.h and remove it.
With this patch, sound/driver.h isn't removed but has just a single
compile warning to include it. This should be really killed in
future.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] Remove PCM sleep_min and tick

The 'tick' in PCM is set (again) via sw_params. And, nobody uses
this feature at all except for a command line option of aplay.
(This is literally 'nobody', as I checked alsa-lib API calls in all
programs in major distros.)
Above all, if we need finer wake-ups for the position update, it's
basically an issue that the driver should solve, not tuned by each
application.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] PCM - clean up snd_pcm_lib_read/write

Introduce a common helper function for snd_pcm_lib_read and snd_pcm_lib_write
for cleaning up the code.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] Remove PCM xfer_align sw params

The xfer_align sw_params parameter has never been used in a sane manner,
and no one understands what this does exactly. The current
implementation looks also buggy because it allows write of shorter size
than xfer_align. So, if you do partial writes, the write isn't actually
aligned at all.
Removing this parameter will make some pcm_lib_* code more readable
(and less buggy).

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] Fix PCM write blocking

The snd_pcm_lib_write1() may block in some weird condition:
- the stream isn't started
- avail_min is big (e.g. period size)
- partial write up to buffer_size - avail_min
The patch fixes this invalid blocking problem.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] pcm_lib: fix sparse warning about different signedness

pcm_lib: fix sparse warning about different signedness

Signed-off-by: Marcin Ślusarz <marcin.slusarz@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] pcm_lib: fix sparse warning about shadowing 'n' symbol

pcm_lib: fix sparse warning about shadowing 'n' symbol

Signed-off-by: Marcin Ślusarz <marcin.slusarz@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] Use posix clock monotonic for PCM and timer timestamps

We need an accurate and continuous (monotonic) time sources to do
accurate synchronization among more timing sources. This patch allows
to enable monotonic timestamps for ALSA PCM devices and enables monotonic
timestamps for ALSA timer devices.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] Fix PCM MMAP time-stamp mode

When MMAP time-stamp mode is given, it's supposed to update the time-stamp
only at period boundary. However, it currently updates at each status call
so this is just useless. The patch fixes this misbehavior.
Also it fixes the wrong check of tstamp_mode (don't use bit-and for enum).

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] Changed Jaroslav Kysela's e-mail from perex@suse.cz to perex@perex.cz


Signed-off-by: Jaroslav Kysela <perex@perex.cz>

[ALSA] Fix possible invalid memory access in PCM core

snd_internval_list() may access invalid memory in the case count = 0
is given. It shouldn't be passed, but it'd better to make the code
a bit more robust.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

[ALSA] pcm core: fix silence_start calculations

The case where silence_size < boundary was broken because different
parts of the snd_pcm_playback_silence() function disagreed about whether
silence_start should point to the start or to the end of the buffer part
to be silenced.
This patch changes the code to always use to the start, which also
simplifies several calculations.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

[ALSA] Add O_APPEND flag support to PCM

Added O_APPEND flag support to PCM to enable shared substreams
among multiple processes. This mechanism is used by dmix and
dsnoop plugins.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] Clean up ugly hacks in pcm_lib.c

Clean up ugly hacks for sync with alsa-lib code in pcm_lib.c.
Also, optimize snd_pcm_hw_params_choose() with a loop.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] Move OSS-specific hw_params helper to snd-pcm-oss module

Move EXPORT_SYMBOL()s to places adjacent to functions/variables.
Also move OSS-specific hw_params helper functions to pcm_oss.c.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] PCM core - introduce CONFIG_SND_PCM_XRUN_DEBUG

This patch makes the XRUN (overrun/underrun) notification code optional.

Signed-off-by: Jaroslav Kysela <perex@suse.cz>

[ALSA] Clean up PCM codes (take 2)

- Clean up initialization and destruction of substream instance
Now snd_pcm_open_substream() alone does most initialization jobs.
Add pcm_release callback for cleaning up at snd_pcm_release_substream()
- Tidy up PCM oss code

Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] pcm - Fix wrong asserts

Modules: PCM Midlevel

Fixed wrong or supreflous snd_assert()'s.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] Remove xxx_t typedefs: PCM

Modules: PCM Midlevel

Remove xxx_t typedefs from the core PCM codes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] Use getnstimeofday()

Modules: Documentation,PCM Midlevel,Timer Midlevel,ALSA Core

Use the standard getnstimeofday() function instead of ALSA's own one.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] Remove snd_runtime_check() macro

Remove snd_runtime_check() macro.
This macro worsens the readability of codes. They should be either
normal if() or removable asserts.

Also, the assert displays stack-dump, instead of only the last caller
pointer.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] Fix DocBook warnings

PCM Midlevel,RawMidi Midlevel
Fix DocBook warnings.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] make local objects static

Memalloc module,PCM Midlevel,Timer Midlevel,GUS Library,AC97 Codec
ALI5451 driver,RME9652 driver
Make some functions/variables that are used in only one file static.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

[ALSA] ALSA's struct _snd_pcm_substream: Obsolete open_flag

PCM Midlevel,ALSA<-OSS emulation,USB USX2Y
This patch removes open_flag from struct _snd_pcm_substream.
All of its uses are substituted by querying struct _snd_pcm_substream's
member ffile instead.

Signed-off-by: Karsten Wiese <annabellesgarden@yahoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] Make docproc happy

PCM Midlevel
Make docproc happy by moving '#if 0' before comments.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

[ALSA] sound/core/: possible cleanups

PCM Midlevel,ALSA Core,Timer Midlevel,ALSA sequencer,Virtual Midi
This patch contains the following possible cleanups:
- make needlessly global code static
- #if 0 the following unused global functions
- remove the following unneeded EXPORT_SYMBOL's

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!