On Mon, 28 Mar 2022 11:14:11 +0200, Mohan Kumar wrote: > > There is a corner case with unsol event handling during codec runtime > suspending state. When the codec runtime suspend call initiated, the > codec->in_pm atomic variable would be 0, currently the codec runtime > suspend function calls snd_hdac_enter_pm() which will just increments > the codec->in_pm atomic variable. Consider unsol event happened just > after this step and before snd_hdac_leave_pm() in the codec runtime > suspend function. The snd_hdac_power_up_pm() in the unsol event > flow in hdmi_present_sense_via_verbs() function would just increment > the codec->in_pm atomic variable without calling pm_runtime_get_sync > function. > > As codec runtime suspend flow is already in progress and in parallel > unsol event is also accessing the codec verbs, as soon as codec > suspend flow completes and clocks are switched off before completing > the unsol event handling as both functions doesn't wait for each other. > This will result in below errors > > [ 589.428020] tegra-hda 3510000.hda: azx_get_response timeout, switching > to polling mode: last cmd=0x505f2f57 > [ 589.428344] tegra-hda 3510000.hda: spurious response 0x80000074:0x5, > last cmd=0x505f2f57 > [ 589.428547] tegra-hda 3510000.hda: spurious response 0x80000065:0x5, > last cmd=0x505f2f57 > > To avoid this, the unsol event flow should not perform any codec verb > related operations during RPM_SUSPENDING state. > > Signed-off-by: Mohan Kumar <mkumard@xxxxxxxxxx> Thanks, that's a hairy problem... The logic sounds good, but can we check the PM state before calling snd_hda_power_up_pm()? Takashi
