linux/sound
Takashi Iwai fc4f000bf8 ALSA: hda - Fix unexpected resume through regmap code path
HD-audio driver has a mechanism to trigger the runtime resume
automatically at accessing the verbs.  This auto-resume, however,
causes the mutex deadlock when invoked from the regmap handler since
the regmap keeps the mutex while auto-resuming.  For avoiding that,
there is some tricky check in the HDA regmap handler to return -EAGAIN
error to back-off when the codec is powered down.  Then the caller of
regmap r/w will retry after properly turning on the codec power.

This works in most cases, but there seems a slight race between the
codec power check and the actual on-demand auto-resume trigger.  This
resulted in the lockdep splat, eventually leading to a real deadlock.

This patch tries to address the race window by getting the runtime PM
refcount at the check time using pm_runtime_get_if_in_use().  With
this call, we can keep the power on only when the codec has been
already turned on, and back off if not.

For keeping the code consistency, the code touching the runtime PM is
stored in hdac_device.c although it's used only locally in
hdac_regmap.c.

Reported-by: Jiri Slaby <jslaby@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-03-08 10:49:02 +01:00
..
aoa ALSA: aoa-soundbus: Switch to dev_pm_ops 2015-08-05 16:47:47 +02:00
arm ASoC: pxa: pxa-pcm-lib: switch over to snd-soc-dmaengine-pcm 2015-09-30 23:21:16 +01:00
atmel ALSA: sound/atmel/ac97c.c: remove unused variable 2015-05-20 06:18:25 +02:00
core ALSA: seq: oss: Don't drain at closing a client 2016-03-01 20:26:40 +01:00
drivers ALSA: dummy: Implement timer backend switching more safely 2016-02-08 08:15:35 +01:00
firewire ALSA: firewire-digi00x: Drop bogus const type qualifier on dot_scrt() 2016-02-09 12:16:52 +01:00
hda ALSA: hda - Fix unexpected resume through regmap code path 2016-03-08 10:49:02 +01:00
i2c ALSA: i2c: constify snd_i2c_ops structures 2015-11-30 11:40:08 +01:00
isa ALSA: Add missing dependency on CONFIG_SND_TIMER 2016-01-27 07:10:38 +01:00
mips ALSA: mips: let SND_SGI_O2 select SND_PCM 2015-06-15 13:21:58 +02:00
oss sound/oss: remove VIRT_TO_BUS dependency 2015-12-09 14:40:51 +01:00
parisc
pci ALSA: hda - hdmi defer to register acomp eld notifier 2016-03-04 08:40:24 +01:00
pcmcia
ppc ALSA: ppc: Add missing inclusion of linux/module.h 2015-08-25 14:13:36 +02:00
sh
soc Merge remote-tracking branches 'asoc/fix/wm8985', 'asoc/fix/wm8994', 'asoc/fix/wm8996', 'asoc/fix/wm9081' and 'asoc/fix/wm9713' into asoc-linus 2016-03-05 21:27:13 +09:00
sparc ALSA: Add missing dependency on CONFIG_SND_TIMER 2016-01-27 07:10:38 +01:00
spi ALSA: at73c213: manage SSC clock 2016-01-20 09:59:27 +01:00
synth ALSA: emux: constify nrpn_conv_table structures 2016-01-06 10:19:49 +01:00
usb ALSA: usb-audio: Add a quirk for Plantronics DA45 2016-03-01 14:40:52 +01:00
ac97_bus.c ASoC: Updates for v4.3 2015-08-31 16:25:22 +02:00
Kconfig
last.c
Makefile
sound_core.c sound: fix check for error condition of register_chrdev() 2015-11-07 11:14:30 +01:00
sound_firmware.c sound: sound_firmware: Fix invalid use of vfs_read() 2015-05-26 13:48:58 +02:00