ALSA: aloop: Replace with DEFINE_SIMPLE_DEV_PM_OPS()

Use the new DEFINE_SIMPLE_DEV_PM_OPS() instead of SIMPLE_DEV_PM_OPS()
for code-simplification. We need no longer CONFIG_PM_SLEEP ifdefs.
Just a cleanup, no functional changes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240207155140.18238-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Introduce a function to get if access is interleaved mode

There's a use case that playback stream of a loopback cable works on
RW_INTERLEAVED mode while capture stream works on MMAP_INTERLEAVED mode:

aplay -Dhw:Loopback,0,0 S32_48K_2ch.wav;
arecord -Dplughw:Loopback,1,0 -fS32_LE -r16000 -c2 cap.wav;

The plug plugin handles only slave PCM support MMAP mode. Not only plug
plugin but also other plugins like direct plugins(dmix/dsnoop/dshare)
work on MMAP access mode. In this case capture stream is the slave
PCM works on MMAP_INTERLEAVED mode. However loopback_check_format()
rejects this access setting and return:

arecord: pcm_read:2240: read error: Input/output error

To fix it a function called is_access_interleaved() is introduced to
get if access is interleaved mode. If both access of capture stream and
playback stream is interleaved mode loopback_check_format() will allow
this kind of access setting.

Fixes: 462494565c27 ("ALSA: aloop: Add support for the non-interleaved access mode")
Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
Link: https://lore.kernel.org/r/20240111025219.2678764-1-chancel.liu@nxp.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Add control element for getting the access mode

Add new control element 'PCM Slave Access Mode' which shows the access
mode (interleaved/non-interleaved) for the PCM playing device. Add
corresponding control change notification calls.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230927113555.14877-2-ivan.orlov0322@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Add support for the non-interleaved access mode

The current version of the loopback driver supports interleaved access
mode only. This patch introduces support for the non-interleaved
access mode.

When in the interleaved mode, the 'copy_play_buf' function copies data
from the playback to the capture buffer using one memcpy call. This call
copies samples for multiple, interleaved channels.

In the non-interleaved mode we have multiple channel buffers, so we have
to perform multiple memcpy calls to copy samples channel after channel.

Add new function called 'copy_play_buf_part_n', which copies a part of
each channel buffer from playback to capture. Modify the 'copy_play_buf'
to use the corresponding memory copy function(just memcpy /
copy_play_buf_part_n) depending on the access mode.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230927113555.14877-1-ivan.orlov0322@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Replace runtime->status->state reference to runtime->state

The recent change in ALSA core allows drivers to get the current PCM
state directly from runtime object. Replace the calls accordingly.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220926135558.26580-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Fix random zeros in capture data when using jiffies timer

In loopback_jiffies_timer_pos_update(), we are getting jiffies twice.
First time for playback, second time for capture. Jiffies can be updated
between these two calls and if the capture jiffies is larger, extra zeros
will be filled in the capture buffer.

Change to get jiffies once and use it for both playback and capture.

Signed-off-by: Pattara Teerapong <pteerapong@chromium.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220901144036.4049060-1-pteerapong@chromium.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Allocate resources with device-managed APIs

Use the new snd_devm_card_new() for the card object allocation, and
clean up the superfluous remove callback.

Link: https://lore.kernel.org/r/20210715075941.23332-78-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Fix initialization of controls

Add a control to the card before copying the id so that the numid field
is initialized in the copy. Otherwise the numid field of active_id,
format_id, rate_id and channels_id will be the same (0) and
snd_ctl_notify() will not queue the events properly.

Signed-off-by: Jonas Holmberg <jonashg@axis.com>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210407075428.2666787-1-jonashg@axis.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

module: remove never implemented MODULE_SUPPORTED_DEVICE

MODULE_SUPPORTED_DEVICE was added in pre-git era and never was
implemented. We can safely remove it, because the kernel has grown
to have many more reliable mechanisms to determine if device is
supported or not.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ALSA: aloop: Use DIV_ROUND_UP() instead of open-coding it

Use DIV_ROUND_UP() instead of open-coding it. This documents intent
and makes it more clear what is going on for the casual reviewer.

Generated using the following the Coccinelle semantic patch.

// <smpl>
@@
expression x, y;
@@
-(((x) + (y) - 1) / (y))
+DIV_ROUND_UP(x, y)
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20201223172229.781-2-lars@metafoo.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Constify ops structs

The only usage of the ops field in the loopback_cable struct is to call
its members, the field it self is never changed. Make it a pointer to
const. This allows us to constify two static loopback_ops structs to
allow the compiler to put them in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20201120231046.76758-1-rikard.falkeborn@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Replace tasklet with work

The tasklet is an old API that should be deprecated, usually can be
converted to another decent API. In aloop driver, a tasklet is still
used for offloading the timer event task. It can be achieved
gracefully with a work queued, too.

This patch replaces the tasklet usage in aloop driver with a simple
work.

Link: https://lore.kernel.org/r/20200903104131.21097-6-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Fix PCM format assignment

Fix sparse warnings about PCM format assignment regarding the strong
typed snd_pcm_format_t:
sound/drivers/aloop.c:352:45: warning: restricted snd_pcm_format_t degrades to integer
sound/drivers/aloop.c:355:39: warning: incorrect type in assignment (different base types)
sound/drivers/aloop.c:355:39: expected unsigned int format
sound/drivers/aloop.c:355:39: got restricted snd_pcm_format_t [usertype] format
sound/drivers/aloop.c:1435:34: warning: incorrect type in assignment (different base types)
sound/drivers/aloop.c:1435:34: expected long max
sound/drivers/aloop.c:1435:34: got restricted snd_pcm_format_t [usertype]
sound/drivers/aloop.c:1565:39: warning: incorrect type in assignment (different base types)
sound/drivers/aloop.c:1565:39: expected unsigned int format
sound/drivers/aloop.c:1565:39: got restricted snd_pcm_format_t [usertype]

Some code in this driver assigns an integer value to snd_pcm_format_t
via control API, and they need to be with the explicit cast.

No functional changes, just sparse warning fixes.

Link: https://lore.kernel.org/r/20200206163945.6797-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: drivers: Constify snd_kcontrol_new items

Most of snd_kcontrol_new definitions are read-only and passed as-is.
Let's declare them as const for further optimization.
Constify snd_kcontrol_new items

There should be no functional changes by this patch.

Link: https://lore.kernel.org/r/20200103081714.9560-34-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.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: drivers: Drop superfluous ioctl PCM ops

PCM core deals the empty ioctl field now as default(*).
Let's kill the redundant lines.

(*) commit fc033cbf6fb7 ("ALSA: pcm: Allow NULL ioctl ops")

Link: https://lore.kernel.org/r/20191210061145.24641-5-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Use managed buffer allocation

Clean up the driver with the new managed buffer allocation API.
The hw_params callback became superfluous and got dropped.

Link: https://lore.kernel.org/r/20191209094943.14984-5-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Avoid pointer dereference before null-check

Static analysis tools (cppcheck and PVS Studio) report an error
in loopback_snd_timer_period_elapsed() regarding dpcm_play pointer
dereference earlier than its null-check. And although this is a result
of a formal check, and the pointer correctness is also protected
by having a corresponding bit set in the "running" mask, re-ordering
of the lines can imake the code even formally correct and eliminate
those static analysis error reports.

Fixes: 26c53379f98d ("ALSA: aloop: Support selection of snd_timer instead of jiffies")
Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Link: https://lore.kernel.org/r/20191127110622.26105-1-andrew_gabbasov@mentor.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Avoid unexpected timer event callback tasklets

loopback_snd_timer_close_cable() function waits until all
scheduled tasklets are completed, but the timer is closed after that
and can generate more event callbacks, scheduling new tasklets,
that will not be synchronized with cable closing.
Move tasklet_kill() call to be executed after snd_timer_close()
call to avoid such case.

Fixes: 26c53379f98d ("ALSA: aloop: Support selection of snd_timer instead of jiffies")
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Link: https://lore.kernel.org/r/20191122175218.17187-2-andrew_gabbasov@mentor.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Remove redundant locking in timer open function

loopback_parse_timer_id() uses snd_card_ref(), that can lock on mutex,
also snd_timer_instance_new() uses non-atomic allocation, that can sleep.
So, both functions can not be called from loopback_snd_timer_open()
with cable->lock spinlock locked.

Moreover, most part of loopback_snd_timer_open() function body works
when the opposite stream of the same cable does not yet exist, and
the current stream is not yet completely open and can't be running,
so existing locking of loopback->cable_lock mutex is enough to protect
from conflicts with simultaneous opening or closing.
Locking of cable->lock spinlock is not needed in this case.

Fixes: 26c53379f98d ("ALSA: aloop: Support selection of snd_timer instead of jiffies")
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Link: https://lore.kernel.org/r/20191122175218.17187-1-andrew_gabbasov@mentor.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Support runtime change of snd_timer via info interface

Show and change sound card timer source with read-write info
file in proc filesystem. Initial string can still be set as
module parameter.

The timer source string value can be changed at any time,
but it is latched by PCM substream open callback (the first one
for a particular cable). At this point it is actually used, that
is the string is parsed, and the timer is looked up and opened.

The timer source is set for a loopback card (the same as initial
setting by module parameter), but every cable uses the value,
current at the moment of open.

Setting the value to empty string switches the timer to jiffies.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Link: https://lore.kernel.org/r/20191120174955.6410-8-andrew_gabbasov@mentor.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Support selection of snd_timer instead of jiffies

to do synchronous audio forwarding between hardware sound card and aloop
devices. Such an audio route could look like the following:
Sound card -> Loopback application -> ALSA loop device -> arecord

In this case the loopback device should use the sound timer of the sound
card. Without this patch the loopback application has to implement an
adaptive sample rate converter to align the different clocks of the
different ALSA devices.

The used timer can be selected by referring to a sound card, its device
and subdevice, when loading the module:
$ modprobe snd_aloop enable=1 timer_source=[<card>[.<dev>[.<subdev>]]]
<card> is the name (id) of the sound card or a card number.
<dev> and <subdev> are device and subdevice numbers (defaults are 0).
Empty string as a value of timer_source= parameter enables previous
functionality (using jiffies timer).

Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Link: https://lore.kernel.org/r/20191120174955.6410-7-andrew_gabbasov@mentor.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Move CABLE_VALID_BOTH to the top of file

so all functions can use the same.

Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Link: https://lore.kernel.org/r/20191120174955.6410-6-andrew_gabbasov@mentor.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Rename all jiffies timer specific functions

This commit does not change the behaviour. It only separates the jiffies
timer specific implementation from the generic part.

Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Link: https://lore.kernel.org/r/20191120174955.6410-5-andrew_gabbasov@mentor.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Use callback functions for timer specific implementations

This commit only refactors the implementation. It does not change the
behaviour.
It is required to support other timers (e.g sound timer).

Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Link: https://lore.kernel.org/r/20191120174955.6410-4-andrew_gabbasov@mentor.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Support return of error code for timer start and stop

This is required for additional timer implementations which could detect
errors and want to throw them.

Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Link: https://lore.kernel.org/r/20191120174955.6410-3-andrew_gabbasov@mentor.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Describe units of variables

Describe the unit of the variables used to calculate the hw pointer
depending on jiffies ticks.

Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Link: https://lore.kernel.org/r/20191120174955.6410-2-andrew_gabbasov@mentor.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Convert to the common vmalloc memalloc

The recent change (*) in the ALSA memalloc core allows us to drop the
special vmalloc-specific allocation and page handling. This patch
coverts to the common code.
(*) 1fe7f397cfe2: ALSA: memalloc: Add vmalloc buffer allocation
support
7e8edae39fd1: ALSA: pcm: Handle special page
mapping in the default mmap handler

Link: https://lore.kernel.org/r/20191105151856.10785-10-tiwai@suse.de
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: aloop: Support S24 sample formats

Currently snd_aloop supports only S16 and S32 audio sample formats. With
this patch the S24 formats are also supported.

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

ALSA: drivers: Clean up with new procfs helpers

Simplify the proc fs creation code with new helper functions,
snd_card_ro_proc_new() and snd_card_rw_proc_new().
Just a code refactoring and no functional changes.

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

ALSA: drivers: Remove superfluous snd_pcm_suspend*() calls

The call of snd_pcm_suspend_all() & co became superfluous since we
call it in the PCM PM ops. Let's remove them.

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

ALSA: pcm: Nuke snd_pcm_lib_mmap_vmalloc()

snd_pcm_lib_mmap_vmalloc() was supposed to be implemented with
somewhat special for vmalloc handling, but in the end, this turned to
just the default handler, i.e. NULL. As the situation has never
changed over decades, let's rip it off.

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

ALSA: aloop: Reduced duplicated PCM ops definition

The PCM ops defined for playback and capture are identical. Just use
the single one for both.

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

ALSA: aloop: Add missing cable lock to ctl API callbacks

Some control API callbacks in aloop driver are too lazy to take the
loopback->cable_lock and it results in possible races of cable access
while it's being freed. It eventually lead to a UAF, as reported by
fuzzer recently.

This patch covers such control API callbacks and add the proper mutex
locks.

Reported-by: DaeRyong Jeong <threeearcat@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Mark paused device as inactive

Show paused ALSA aloop device as inactive, i.e. the control
"PCM Slave Active" set as false. Notification sent upon state change.

This makes it possible for client capturing from aloop device to know if
data is expected. Without it the client expects data even if playback
is paused.

Signed-off-by: Robert Rosengren <robert.rosengren@axis.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Fix access to not-yet-ready substream via cable

In loopback_open() and loopback_close(), we assign and release the
substream object to the corresponding cable in a racy way. It's
neither locked nor done in the right position. The open callback
assigns the substream before its preparation finishes, hence the other
side of the cable may pick it up, which may lead to the invalid memory
access.

This patch addresses these: move the assignment to the end of the open
callback, and wrap with cable->lock for avoiding concurrent accesses.

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

ALSA: aloop: Sync stale timer before release

The aloop driver tries to stop the pending timer via timer_del() in
the trigger callback and in the close callback. The former is
correct, as it's an atomic operation, while the latter expects that
the timer gets really removed and proceeds the resource releases after
that. But timer_del() doesn't synchronize, hence the running timer
may still access the released resources.

A similar situation can be also seen in the prepare callback after
trigger(STOP) where the prepare tries to re-initialize the things
while a timer is still running.

The problems like the above are seen indirectly in some syzkaller
reports (although it's not 100% clear whether this is the only cause,
as the race condition is quite narrow and not always easy to
trigger).

For addressing these issues, this patch adds the explicit alls of
timer_del_sync() in some places, so that the pending timer is properly
killed / synced.

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

ALSA: aloop: Fix racy hw constraints adjustment

The aloop driver tries to update the hw constraints of the connected
target on the cable of the opened PCM substream. This is done by
adding the extra hw constraints rules referring to the substream
runtime->hw fields, while the other substream may update the runtime
hw of another side on the fly.

This is, however, racy and may result in the inconsistent values when
both PCM streams perform the prepare concurrently. One of the reason
is that it overwrites the other's runtime->hw field; which is not only
racy but also broken when it's called before the open of another side
finishes. And, since the reference to runtime->hw isn't protected,
the concurrent write may give the partial value update and become
inconsistent.

This patch is an attempt to fix and clean up:
- The prepare doesn't change the runtime->hw of other side any longer,
but only update the cable->hw that is referred commonly.
- The extra rules refer to the loopback_pcm object instead of the
runtime->hw. The actual hw is deduced from cable->hw.
- The extra rules take the cable_lock to protect against the race.

Fixes: b1c73fc8e697 ("ALSA: snd-aloop: Fix hw_params restrictions and checking")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Fix inconsistent format due to incomplete rule

The extra hw constraint rule for the formats the aloop driver
introduced has a slight flaw, where it doesn't return a positive value
when the mask got changed. It came from the fact that it's basically
a copy&paste from snd_hw_constraint_mask64(). The original code is
supposed to be a single-shot and it modifies the mask bits only once
and never after, while what we need for aloop is the dynamic hw rule
that limits the mask bits.

This difference results in the inconsistent state, as the hw_refine
doesn't apply the dependencies fully. The worse and surprisingly
result is that it causes a crash in OSS emulation when multiple
full-duplex reads/writes are performed concurrently (I leave why it
triggers Oops to readers as a homework).

For fixing this, replace a few open-codes with the standard
snd_mask_*() macros.

Reported-by: syzbot+3902b5220e8ca27889ca@syzkaller.appspotmail.com
Fixes: b1c73fc8e697 ("ALSA: snd-aloop: Fix hw_params restrictions and checking")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Release cable upon open error path

The aloop runtime object and its assignment in the cable are left even
when opening a substream fails. This doesn't mean any memory leak,
but it still keeps the invalid pointer that may be referred by the
another side of the cable spontaneously, which is a potential Oops
cause.

Clean up the cable assignment and the empty cable upon the error path
properly.

Fixes: 597603d615d2 ("ALSA: introduce the snd-aloop module for the PCM loopback")
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: drivers: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: drivers: constify snd_pcm_ops structures

snd_pcm_ops are not supposed to change at runtime. All functions
working with snd_pcm_ops provided by <sound/pcm.h> work with
const snd_pcm_ops. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: drivers: make snd_pcm_hardware const

Make these const as they are only used in a copy operation.
Done using Coccinelle.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Drop unnecessary ifdef CONFIG_PROC_FS

Since the compiler can optimize away the unused code, we can reduce
the messy ifdef.

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

ALSA: aloop: Use setup_timer() and mod_timer()

No functional change, refactoring with the standard helpers.

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

ALSA: drivers: drop owner assignment from platform_drivers

A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

ALSA: drivers: Convert to snd_card_new() with a device pointer

Also remove superfluous snd_card_set_dev() calls.

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

ALSA: aloop: Remove redundant platform_set_drvdata()

Commit 0998d06310 (device-core: Ensure drvdata = NULL when no
driver is bound) removes the need to set driver data field to
NULL.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm_format_to_bits strong-typed conversion

Add a function to handle conversion from snd_pcm_format_t
to bitwise with proper typing.

Change such conversions to use this function and silence sparse
warnings.

Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop: Fix Oops while PM resume

snd-aloop driver has no proper PM implementation, thus the PM resume
may trigger Oops due to leftover timer instance. This patch adds the
missing suspend/resume implementation.

Reported-and-tested-by: El boulangero <elboulangero@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: drivers: remove __dev* attributes

CONFIG_HOTPLUG is going away as an option. As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop - Close races at restarting the stream

There are small races opened in the check of running bit and the timer
lock. Instead of adding yet more flag, just protect the whole racy
codes with the existing cable->lock. As a bonus, we can get rid of
timer_lock now.

Reported-and-tested-by: Omair Mohammed Abdullah <omair.m.abdullah@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: aloop - add locking to timer access

When the loopback timer handler is running, calling del_timer() (for STOP
trigger) will not wait for the handler to complete before deactivating the
timer. The timer gets rescheduled in the handler as usual. Then a subsequent
START trigger will try to start the timer using add_timer() with a timer pending
leading to a kernel panic.

Serialize the calls to add_timer() and del_timer() using a spin lock to avoid
this.

Signed-off-by: Omair Mohammed Abdullah <omair.m.abdullah@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: platform: Check CONFIG_PM_SLEEP instead of CONFIG_PM

When CONFIG_PM is set but CONFIG_PM_SLEEP is unset,
SIMPLE_DEV_PM_OPS() ignores the given functions, and this leads to
compile warnings.

For avoiding this, simply check CONFIG_PM_SLEEP instead of CONFIG_PM.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: convert PM ops of platform_driver to new pm ops

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

ALSA: Add missing .owner=THIS_MODULE to platform_driver definitions

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

ALSA: snd-aloop - improve the sample copy accurracy

Maintain both streams (playback, capture) synchronized. Previous code
didn't take in account the small byte count drifts caused by the irq
position rounding.

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

ALSA: module_param: make bool parameters really bool

module_param(bool) used to counter-intuitively take an int. In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

It's time to remove the int/unsigned int option. For this version
it'll simply give a warning, but it'll break next kernel version.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound: fix drivers needing module.h not moduleparam.h

The implicit presence of module.h lured several users into
incorrectly thinking that they only needed/used modparam.h
but once we clean up the module.h presence, these will show
up as build failures, so fix 'em now.

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

ALSA: aloop - Use vmalloc buffer

snd-aloop driver is virtual and has no need for allocating contiguous
pages. It'll be more system-friendly to use vmalloc buffers.

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

ALSA: aloop - Fix possible IRQ lock inversion

loopback_pos_update() can be called in the timer callback, thus the lock
held should be irq-safe. Otherwise you'll get AB/BA deadlock together
with substream->self_group.lock.

Reported-and-tested-by: Knut Petersen <Knut_Petersen@t-online.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: snd-aloop - add pause support

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

ALSA: snd-aloop - fix locking issues (running flag updates)

On SMP machines, the cable->running update must be atomic, otherwise
stream is not started correctly sometimes.

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

ALSA: snd-aloop: add cable#0 and cable#1 files to proc card tree

Show some useful runtime information using procfs.

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

ALSA: snd-aloop - fix issue in the timer start function

In some circumstances (the rate shift value was changed), the irq_pos
value may be higher than the fraction value in the timer start function.
Check for it.

Also, to avoid value overflow, decrease maximum period size.

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

ALSA: snd-aloop: Fix hw_params restrictions and checking

This patch fixes the hw_params restrictions when first (or playback) stream
sets the final hardware parameters. Also, fix the hw_params checking
in the trigger callback.

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

ALSA: snd-aloop - fix "PCM Slave Active" element read value

Simple coding fix.

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

ALSA: snd-aloop - fix capture buffer silence

In a special case, some old samples are left in the capture ring buffer.
Fix it.

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

ALSA: snd-aloop - fix the "PCM Playback Channels" kcontrol

Obvious copy-and-paste error.

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

ALSA: introduce the snd-aloop module for the PCM loopback

The snd-aloop module allows redirecting of the PCM playback in the
kernel back to the user space using the standard ALSA PCM capture API.

The module also allows time synchronization with another timing source
and notifications of playback stream parameter changes.

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