Messages in this thread | | | Subject | Re: [BUG] sound: pci: trident: a possible data race | From | Jia-Ju Bai <> | Date | Thu, 4 Oct 2018 11:08:45 +0800 |
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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.
> 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 ;)
Best wishes, Jia-Ju Bai
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