ALSA: oss: Use DIV_ROUND_CLOSEST() instead of open-coding it

Use DIV_ROUND_CLOSEST() 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) / 2)) / (y)
+DIV_ROUND_CLOSEST(x, y)
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20201223172229.781-13-lars@metafoo.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: core: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200211193910.GA4596@embeddedor
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: pcm: oss: Use struct_size() helper

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace the following form:

sizeof(struct rate_priv) + src_format->channels * sizeof(struct rate_channel)

with:

struct_size(data, channels, src_format->channels)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

ALSA: fix excessive background noise introduced by OSS emulation rate shrink

Incorrect variable was used to get the next sample which caused S2
to be stuck with the same value resulting in loud background noise.

Signed-off-by: Steve Chen <schen at mvista.com>
Cc: <stable@kernel.org>
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] 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] Changed Jaroslav Kysela's e-mail from perex@suse.cz to perex@perex.cz


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

[ALSA] Remove ifdefs from OSS PCM emulation codes

Fix Makefile to compile files conditionally to CONFIG_SND_PCM_OSS_PLUGINS,
and remove unneeded ifdefs in these files.

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

[ALSA] Clean up pcm-oss plugins

Modules: ALSA<-OSS emulation

Clean up pcm-oss plugin codes.
Removed dead codes, and simplified route/rate plugins.

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

[ALSA] PCM midlevel & PCM OSS - make procfs & OSS plugin code optional

Modules: ALSA Core,PCM Midlevel,ALSA<-OSS emulation,USB generic driver

1) The verbose procfs code for the PCM midlevel and usb audio
can be removed now (more patches will follow).
CONFIG_SND_VERBOSE_PROCFS
2) The PCM OSS plugin system can be also compiled optionaly.
CONFIG_SND_PCM_OSS_PLUGINS

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

[ALSA] Remove xxx_t typedefs: PCM OSS-emulation

Modules: ALSA<-OSS emulation

Remove xxx_t typedefs from the core PCM OSS-emulation codes.

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

[ALSA] Use standard bitmap functions

Modules: ALSA<-OSS emulation

Use standard bitmap functions instead of in-house ones.

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!