[alsa-devel] [PATCH 0/9] Misc fixes related to rewinds

[Jaroslav Kysela]

Date 13.9.2014 20:30, Alexander E. Patrakov wrote:
> The idea of the series is to fix the two issues that I found [1] for the

I applied all your patches to alsa-lib's repo, but...

> hw plugin. snd_pcm_rewindable() sometimes returned negative values that
> are actually negative amounts of samples and not error codes. Also, it
> bases its calculations on stale hardware position pointer, which is not
> what PulseAudio wants (alternatively, we can document the need to call
> snd_pcm_avail() before snd_pcm_rewindable(), but I don't like it).

The hw sync is expensive and the application might do this sync multiple
times when woken up. I think that it must be clear that:

1) only snd_pcm_avail(), snd_pcm_delay(), snd_pcm_avail_delay()
   does the real hw sync
2) snd_pcm_avail(), snd_pcm_delay(), snd_pcm_avail_delay(),
   snd_pcm_rewindable() and snd_pcm_forwardable() does
   hw sync (and change all plugins to respect this)

I don't like the situation "be somewhere between because it's good for
one purpose"...

			Thanks for your work,
                                           Jaroslav

BTW: I'm starting to think about the 1.0.29 release...

-- 
Jaroslav Kysela <perex at perex.cz>
Linux Kernel Sound Maintainer
ALSA Project; Red Hat, Inc.