kernel_optimize_test/sound
Takashi Iwai 1a462be52f ALSA: hda: Manage concurrent reg access more properly
In the commit 8e85def572 ("ALSA: hda: enable regmap internal
locking"), we re-enabled the regmap lock due to the reported
regression that showed the possible concurrent accesses.  It was a
temporary workaround, and there are still a few opened races even
after the revert.  In this patch, we cover those still opened windows
with a proper mutex lock and disable the regmap internal lock again.

First off, the patch introduces a new snd_hdac_device.regmap_lock
mutex that is applied for each snd_hdac_regmap_*() call, including
read, write and update helpers.  The mutex is applied carefully so
that it won't block the self-power-up procedure in the helper
function.  Also, this assures the protection for the accesses without
regmap, too.

The snd_hdac_regmap_update_raw() is refactored to use the standard
regmap_update_bits_check() function instead of the open-code.  The
non-regmap case is still open-coded but it's an easy part.  The all
read and write operations are in the single mutex protection, so it's
now race-free.

In addition, a couple of new helper functions are added:
snd_hdac_regmap_update_raw_once() and snd_hdac_regmap_sync().  Both
are called from HD-audio legacy driver.  The former is to initialize
the given verb bits but only once when it's not initialized yet.  Due
to this condition, the function invokes regcache_cache_only(), and
it's now performed inside the regmap_lock (formerly it was racy) too.
The latter function is for simply invoking regcache_sync() inside the
regmap_lock, which is called from the codec resume call path.
Along with that, the HD-audio codec driver code is slightly modified /
simplified to adapt those new functions.

And finally, snd_hdac_regmap_read_raw(), *_write_raw(), etc are
rewritten with the helper macro.  It's just for simplification because
the code logic is identical among all those functions.

Tested-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20200109090104.26073-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-01-13 13:40:41 +01:00
..
ac97 ALSA: ac97: Constify snd_ac97_bus_ops definitions 2020-01-03 09:24:11 +01:00
aoa ALSA: aoa: More constifications 2020-01-05 16:14:27 +01:00
arm ALSA: arm: More constification 2020-01-05 16:15:07 +01:00
atmel ALSA: atmel: Constify snd_ac97_bus_ops definitions 2020-01-03 09:24:12 +01:00
core ALSA: timer: fix nsec/sec initialization confusion 2020-01-12 09:08:22 +01:00
drivers ALSA: serial-u16550: More constification 2020-01-05 16:15:08 +01:00
firewire ALSA: dice: add support for Alesis MasterControl 2020-01-13 10:44:30 +01:00
hda ALSA: hda: Manage concurrent reg access more properly 2020-01-13 13:40:41 +01:00
i2c ALSA: i2c: Constify snd_kcontrol_new items 2020-01-03 09:24:24 +01:00
isa ALSA: sc6000: More constification 2020-01-05 16:15:05 +01:00
mips ALSA: mips: Constify snd_device_ops definitions 2020-01-03 09:24:02 +01:00
oss compat_ioctl: remove translation for sound ioctls 2019-10-23 17:23:45 +02:00
parisc ALSA: parisc: Constify snd_kcontrol_new items 2020-01-03 09:24:35 +01:00
pci ALSA: hda: Manage concurrent reg access more properly 2020-01-13 13:40:41 +01:00
pcmcia ALSA: pdaudiocf: More constification 2020-01-05 16:15:13 +01:00
ppc ALSA: ppc: More constifications 2020-01-05 16:14:43 +01:00
sh ALSA: sh: Fix compile warning wrt const 2020-01-05 16:15:14 +01:00
soc Merge branch 'for-linus' into for-next 2020-01-11 09:03:40 +01:00
sparc ALSA: sparc: More constifications 2020-01-05 16:14:56 +01:00
spi ALSA: spi: More constification 2020-01-05 16:15:13 +01:00
synth ALSA: emux: More constifications 2020-01-05 16:14:46 +01:00
usb ALSA: usb-audio: Add boot quirk for MOTU M Series 2020-01-13 10:47:56 +01:00
x86 ALSA: x86: Drop superfluous ioctl PCM ops 2019-12-11 07:25:34 +01:00
xen ALSA: xen: Drop superfluous ioctl PCM ops 2019-12-11 07:25:35 +01:00
ac97_bus.c ALSA: ac97: Treat snd_ac97_bus_ops as const 2020-01-03 09:24:08 +01:00
Kconfig
last.c
Makefile
sound_core.c