Currently the selected timer backend is referred at any moment from
the running PCM callbacks.  When the backend is switched, it's
possible to lead to inconsistency from the running backend.  This was
pointed by syzkaller fuzzer, and the commit [7ee96216: ALSA:
dummy: Disable switching timer backend via sysfs] disabled the dynamic
switching for avoiding the crash.

This patch improves the handling of timer backend switching.  It keeps
the reference to the selected backend during the whole operation of an
opened stream so that it won't be changed by other streams.

Together with this change, the hrtimer parameter is reenabled as
writable now.

NOTE: this patch also turned out to fix the still remaining race.
Namely, ops was still replaced dynamically at dummy_pcm_open:

  static int dummy_pcm_open(struct snd_pcm_substream *substream)
  {
  ....
          dummy->timer_ops = &dummy_systimer_ops;
          if (hrtimer)
                  dummy->timer_ops = &dummy_hrtimer_ops;

Since dummy->timer_ops is common among all streams, and when the
replacement happens during accesses of other streams, it may lead to a
crash.  This was actually triggered by syzkaller fuzzer and KASAN.

This patch rewrites the code not to use the ops shared by all streams
any longer, too.

BugLink: http://lkml.kernel.org/r/CACT4Y+aZ+xisrpuM6cOXbL21DuM0yVxPYXf4cD4Md9uw0C3dBQ@mail.gmail.comReported-by: NDmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

ALSA dummy driver can switch the timer backend between system timer
and hrtimer via its hrtimer module option.  This can be also switched
dynamically via sysfs, but it may lead to a memory corruption when
switching is done while a PCM stream is running; the stream instance
for the newly switched timer method tries to access the memory that
was allocated by another timer method although the sizes differ.

As the simplest fix, this patch just disables the switch via sysfs by
dropping the writable bit.

BugLink: http://lkml.kernel.org/r/CACT4Y+ZGEeEBntHW5WHn2GoeE0G_kRrCmUh6=dWyy-wfzvuJLg@mail.gmail.comReported-by: NDmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The dummy_timer_ops structures are never modified, so declare them as
const.

Done with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Although there shouldn't be a problem in practice (the compiler should
handle well), it's better to follow to the new Kconfig.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Add missing prefix to make some local data static.

Spotted by sparse:
  sound/drivers/dummy.c:159:20: warning: symbol 'model_emu10k1' was not declared. Should it be static?
  sound/drivers/dummy.c:165:20: warning: symbol 'model_rme9652' was not declared. Should it be static?
  ....
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Use setup_timer and mod_timer instead of structure assignments as it
is the preferred way to setup and set the timer.
Signed-off-by: NRoman Kollar <rkollar@mail.muni.cz>
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Also remove superfluous snd_card_set_dev() calls.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The usage of strict_strto*() is not preferred, because
strict_strto*() is obsolete. Thus, kstrto*() should be
used.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

A few calls are still left in parport drivers after this commit, which
I'm not quite sure yet.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

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

To make the testing of deactivated mixer controls easier (and for people
with common hardware, possible), add a control that deactivates some
other controls.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>

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: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

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

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

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

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: NPaul Gortmaker <paul.gortmaker@windriver.com>

This is a cleanup for the dummy driver. The model kernel module parameter
is introduced to select the soundcard emulation.
Signed-off-by: NJaroslav Kysela <perex@perex.cz>

Now up to 128 substreams are supported.
Reported-by: NAdrian Bridgett <adrian@smop.co.uk>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In pcm.c, if the NULL test on pcm is needed, then the dereference should be
after the NULL test.

In dummy.c and ali5451.c, the context of the calls to
snd_card_dummy_new_mixer and snd_ali_free_voice show that dummy and pvoice,
respectively cannot be NULL.

A simplified version of the semantic match that detects this problem is as
follows (http://coccinelle.lip6.fr/):

// <smpl>
@match exists@
expression x, E;
identifier fld;
@@

* x->fld
  ... when != \(x = E\|&x\)
* x == NULL
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Increase the limit of PCM substreams to 128.  The default value is
unchanged; only the max accept value is increased.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Added the debug proc file to see or change the snd_pcm_hardware fields
to emulate.  The parameters can be changed by writing to a proc file like:

    # echo periods_min 4 > /proc/asound/card1/dummy_pcm
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Instead of allocating the real buffers, use a fake buffer and ignore
read/write in the dummy driver so that we can save the resources.
For mmap, a single page (unique to the direction, though) is reused
to all buffers.

When the app requires to read/write the real buffers, pass fake_buffer=0
module option at loading time.  This will get back to the old behavior.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Fix the expire-time calculation in the systimer mode when the buffer
size isn't aligned to the period size.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In the system-timer mode, snd-dummy driver issues each tick to update
the position.  This is highly inefficient and even inaccurate if the
timer can't be triggered at each tick.

Now rewritten to wake up only at the period boundary.  The position
is calculated from the current jiffies.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Allow snd-dummy driver to use high-res timer as its timing source
instead of the system timer.  The new module option "hrtimer" is added
to turn on/off the high-res timer support.  It can be switched even
dynamically via sysfs.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Convert from snd_card_new() to the new snd_card_create() function
in other sound subdirectories.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Fixed typos in disabled codes via #if 0.
Signed-off-by: NMariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

checkpatch.pl does not like assignment in if condition
Signed-off-by: NJaroslav Kysela <perex@perex.cz>

The dummy driver uses runtime->private_free but still frees
its pcm structures on error paths.

This is esoteric because the error paths in question are
unreachable. Thus the bug is only a problem when someone
copies this code into other drivers.
Signed-off-by: NDaniel R Thompson <daniel.thompson@st.com>
Signed-off-by: NJaroslav Kysela <perex@perex.cz>

Kill snd_assert() in other places, either removed or replaced with
if () with snd_BUG_ON().
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@perex.cz>

bps is unsigned, a negative snd_pcm_format_width() return value is not noticed
Signed-off-by: NRoel Kluin <12o3l@tiscali.nl>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

when the time interval for a period is smaller than kernel HZ, then
snd-aloop and snd-dummy cannot call snd_pcm_period_elapsed as fast enough
annymore. this happens for example with games. but the app still needs to
see, that the buffer actually did go further, which is provided by these
patches.

Signed-off-by: Ahmet İnan <ainan <at> mathematik.uni-freiburg.de>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Signed-off-by: Ahmet İnan <ainan <at> mathematik.uni-freiburg.de>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

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

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

Clean up codes using the new common snd_ctl_boolean_*_info() callbacks.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@suse.cz>

Something about __init_or_module isn't working as expected (?).
CONFIG_HOTPLUG=y
CONFIG_MODULES=n
Fix shared init/exit code helper:
WARNING: sound/built-in.o(.exit.text+0x243): Section mismatch: reference to .init.text: (between 'alsa_card_mpu401_exit' and 'ac97_bus_exit')
WARNING: sound/built-in.o(.exit.text+0x21b): Section mismatch: reference to .init.text: (between 'alsa_card_dummy_exit' and 'alsa_card_serial_exit')
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@suse.cz>

Fix __devinit and __devexit issues with sound drivers.
Resolves MODPOST warnings similar to:
WARNING: sound/drivers/snd-dummy.o - Section mismatch: reference to .init.text:snd_dummy_probe from .data.rel.local between 'snd_dummy_driver' (at offset 0x0) and 'snd_dummy_controls'
WARNING: sound/drivers/snd-mtpav.o - Section mismatch: reference to .init.text:snd_mtpav_probe from .data.rel.local between 'snd_mtpav_driver' (at offset 0x0) and 'snd_mtpav_input'
WARNING: sound/drivers/snd-virmidi.o - Section mismatch: reference to .init.text:snd_virmidi_probe from .data.rel.local after 'snd_virmidi_driver' (at offset 0x0)
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@suse.cz>

Mark TLV data as 'const'
Signed-of-by: NPhilipp Matthias Hahn <pmhahn@pmhahn.de>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@suse.cz>