Date 15.5.2013 11:55, Arun Raghavan wrote: > Hello, > A number of users have intermittently(?) been hitting a crash in > alsa-lib 1.0.27 [1, 2] related to the softvol plugin. I'm not able to > reproduce this reliably, so can't find an easy way to debug/fix. The problem is that the offsets are not in sync in this case [1]: src_offset = 38560 dst_offset = 38568 frames = 16374 Could you reproduce this bug in any way? At least snd_pcm_dump() before the failing snd_pcm_mmap_commit() call might help to determine what was the status before the assert() was entered. > However, this raises a tangential question - why do we need softvol to > be plugged for 'front' at all? David explained to me that this is to > guarantee the existence of a PCM control. Perhaps I don't fully > understand this, because I'm unconvinced by the reason. Could someone > explain/refute? > > This is especially bad for us, from PulseAudio's perspective, because we > aren't getting a zero-copy path. If the softvol is set to 0dB (no attenuation or gain), then the ring buffer pointers are moved without any sample processing, so the zero-copy functionality is kept. Jaroslav > > Cheers, > Arun > > [1] https://bugzilla.redhat.com/show_bug.cgi?id=953352 > [2] https://bugs.freedesktop.org/show_bug.cgi?id=64299 -- Jaroslav Kysela <perex at perex.cz> Linux Kernel Sound Maintainer ALSA Project; Red Hat, Inc.
