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. And the hardware is very old, I bet only a handful people still using in the whole world :) If we really want to be 100% sure, we may call synchronize_irq() before the NULL-clearing. But there is no way to test the bug nor the fix, so it's fairly moot, IMO. thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
