Oh yes, sorry for not considering that one. Best regards Chengfeng Takashi Iwai <tiwai@xxxxxxx> 于2023年6月27日周二 18:01写道： > > On Tue, 27 Jun 2023 11:56:16 +0200, > Chengfeng Ye wrote: > > > > As &chip->mixer_lock is also acquired by the irq snd_sb8dsp_interrupt() > > which executes under hard-irq context, code executing under process > > context should disable irq before acquiring the lock, otherwise > > deadlock could happen if the process context hold the lock then > > preempt by the interruption. > > > > As the ALSA Driver document described, PCM prepare callbacks are not > > executed with irq disabled by default, thus the acquiring of > > &chip->mixer_lock should be irq disabled. > > > > Possible deadlock scenario: > > snd_sb8_playback_prepare > > -> spin_lock(&chip->mixer_lock); > > <irq interrupt> > > -> snd_sb8dsp_interrupt() > > -> snd_sb8_capture_trigger() > > -> spin_lock(&chip->mixer_lock); (deadlock here) > > > > This flaw was found using an experimental static analysis tool we are > > developing for irq-related deadlock. > > > > The tentative patch fix the potential deadlock by spin_lock_irqsave(). > > > > Signed-off-by: Chengfeng Ye <dg573847474@xxxxxxxxx> > > I believe it's a false-positive. There is already a call > spin_lock_irqsave(&chip->reg_lock, flags); > beforehand. > > > thanks, > > Takashi
