On Thu, 04 Oct 2018 05:08:45 +0200, Jia-Ju Bai wrote: > > Thanks for the reply :) > > > On 2018/10/3 23:54, Takashi Iwai wrote: > > On Wed, 03 Oct 2018 14:50:25 +0200, > > Jia-Ju Bai wrote: > >> CPU0: > >> snd_trident_hw_free > >> snd_trident_free_voice > >> line 3870: spin_lock_irqsave() > >> line 3881: voice->substream = NULL; [WRITE] > >> CPU1: > >> snd_trident_interrupt > >> line 3798: snd_pcm_period_elapsed(voice->substream); [READ] > >> > >> As for voice->substream, the WRITE operation in CPU0 is performed > >> with holding a spinlock, but the READ operation in CPU1 is performed > >> without holding this spinlock, so there may exist a data race. > > Thanks for the report. > > > > The actual crash must be very unlikely, almost 0%, though. > > snd_trident_hw_free() is called always after the PCM stream gets > > stopped via trigger callback, i.e. at the moment, there is no > > corresponding interrupt is generated for that voice entry. > > How about the case that playback and capture are performed concurrently? > Namely, snd_trident_hw_free() is called for playback, and the > interrupt is generated for capture. They are different substreams, hence it won't pick up the substream object. > > And the hardware is very old, I bet only a handful people still using > > in the whole world :) > > I have this hardware, so I am the one of these handful people ;) Wow, that's fun. Then we can really fix the issue, if any. Did you actually hit any relevant bug? thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
