forked from luck/tmp_suning_uos_patched
ea9d0d771f
DPCM can update the FE/BE connection states totally asynchronously from the FE's PCM state. Most of FE/BE state changes are protected by mutex, so that they won't race, but there are still some actions that are uncovered. For example, suppose to switch a BE while a FE's stream is running. This would call soc_dpcm_runtime_update(), which sets FE's runtime_update flag, then sets up and starts BEs, and clears FE's runtime_update flag again. When a device emits XRUN during this operation, the PCM core triggers snd_pcm_stop(XRUN). Since the trigger action is an atomic ops, this isn't blocked by the mutex, thus it kicks off DPCM's trigger action. It eventually updates and clears FE's runtime_update flag while soc_dpcm_runtime_update() is running concurrently, and it results in confusion. Usually, for avoiding such a race, we take a lock. There is a PCM stream lock for that purpose. However, as already mentioned, the trigger action is atomic, and we can't take the lock for the whole soc_dpcm_runtime_update() or other operations that include the lengthy jobs like hw_params or prepare. This patch provides an alternative solution. This adds a way to defer the conflicting trigger callback to be executed at the end of FE/BE state changes. For doing it, two things are introduced: - Each runtime_update state change of FEs is protected via PCM stream lock. - The FE's trigger callback checks the runtime_update flag. If it's not set, the trigger action is executed there. If set, mark the pending trigger action and returns immediately. - At the exit of runtime_update state change, it checks whether the pending trigger is present. If yes, it executes the trigger action at this point. Reported-and-tested-by: Qiao Zhou <zhouqiao@marvell.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org |
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.. | ||
ac97_codec.h | ||
aci.h | ||
ad1816a.h | ||
ad1843.h | ||
adau1373.h | ||
aess.h | ||
ak4xxx-adda.h | ||
ak4113.h | ||
ak4114.h | ||
ak4117.h | ||
ak4531_codec.h | ||
ak4641.h | ||
alc5623.h | ||
asequencer.h | ||
asound.h | ||
asoundef.h | ||
atmel-abdac.h | ||
atmel-ac97c.h | ||
compress_driver.h | ||
control.h | ||
core.h | ||
cs42l52.h | ||
cs42l56.h | ||
cs42l73.h | ||
cs4231-regs.h | ||
cs4271.h | ||
cs8403.h | ||
cs8427.h | ||
da7213.h | ||
da9055.h | ||
designware_i2s.h | ||
dmaengine_pcm.h | ||
emu10k1_synth.h | ||
emu10k1.h | ||
emu8000_reg.h | ||
emu8000.h | ||
emux_legacy.h | ||
emux_synth.h | ||
es1688.h | ||
gus.h | ||
hda_hwdep.h | ||
hda_verbs.h | ||
hwdep.h | ||
i2c.h | ||
info.h | ||
initval.h | ||
jack.h | ||
l3.h | ||
max9768.h | ||
max98088.h | ||
max98090.h | ||
max98095.h | ||
memalloc.h | ||
minors.h | ||
mixer_oss.h | ||
mpu401.h | ||
omap-pcm.h | ||
opl3.h | ||
opl4.h | ||
pcm_oss.h | ||
pcm_params.h | ||
pcm-indirect.h | ||
pcm.h | ||
pt2258.h | ||
pxa2xx-lib.h | ||
rawmidi.h | ||
rcar_snd.h | ||
rt286.h | ||
rt5640.h | ||
rt5645.h | ||
rt5651.h | ||
rt5670.h | ||
rt5677.h | ||
s3c24xx_uda134x.h | ||
sb16_csp.h | ||
sb.h | ||
seq_device.h | ||
seq_kernel.h | ||
seq_midi_emul.h | ||
seq_midi_event.h | ||
seq_oss_legacy.h | ||
seq_oss.h | ||
seq_virmidi.h | ||
sh_dac_audio.h | ||
sh_fsi.h | ||
simple_card.h | ||
snd_wavefront.h | ||
soc-dai.h | ||
soc-dapm.h | ||
soc-dpcm.h | ||
soc.h | ||
soundfont.h | ||
spear_dma.h | ||
spear_spdif.h | ||
sta32x.h | ||
sta350.h | ||
tas2552-plat.h | ||
tas5086.h | ||
tea6330t.h | ||
timer.h | ||
tlv320aic3x.h | ||
tlv320aic32x4.h | ||
tlv320dac33-plat.h | ||
tlv.h | ||
tpa6130a2-plat.h | ||
uda134x.h | ||
uda1380.h | ||
util_mem.h | ||
vx_core.h | ||
wavefront.h | ||
wm0010.h | ||
wm1250-ev1.h | ||
wm2000.h | ||
wm2200.h | ||
wm5100.h | ||
wm8903.h | ||
wm8904.h | ||
wm8955.h | ||
wm8960.h | ||
wm8962.h | ||
wm8993.h | ||
wm8996.h | ||
wm9081.h | ||
wm9090.h | ||
wss.h |