[alsa-devel] Duplicate wake-ups in pcm_lib.c

Jaroslav Kysela perex at perex.cz
Mon Jan 18 22:39:59 CET 2010

On Mon, 18 Jan 2010, Colin Guthrie wrote:

> Hi Jaroslav,
> 'Twas brillig, and Jaroslav Kysela at 07/01/10 14:59 did gyre and gimble:
>> The improved and more clean fix in now in my tree:
>> http://git.alsa-project.org/?p=alsa-kernel.git;a=commitdiff;h=1250932e48d3b698415b1f04775433cf1da688d6
>> Note that you should apply these 4 patches (in reverse order):
>> 4: ALSA: pcm_lib - optimize wake_up() calls for PCM I/O
>> 3: ALSA: pcm_lib - cleanup & merge hw_ptr update functions
>> 2: ALSA: pcm_lib - add possibility to log last 10 DMA ring buffer positions
>> 1: ALSA: pcm_lib.c - convert second xrun_debug() parameter to use defines
>> Patch #3 should definitely fix problems with large avail or delay values
>> reported in PA. I finally figured the culprit (and decide to cleanup all
>> relevant code rather do just another workaround). In other words, new
>> hw_ptr pointer should never be less than previous one now.
> Just wanted to ask about the status of this.
> We included the fixes in Mandriva cooker kernel for wider testing but
> some users are seeing issues.
> These four *seem* to be OK, but after also adding the "something must be
> really wrong" commit
> (http://git.alsa-project.org/?p=alsa-kernel.git;a=commit;h=7b3a177b0d4f92b3431b8dca777313a07533a710)
> folks started getting some errors.
> We also added the jiffies fix commit
> (http://git.alsa-project.org/?p=alsa-kernel.git;a=commit;h=ed69c6a8eef679f2783848ed624897a937a434ac)
> but that didn't seem to help.
> This is handled in our bug report here:
> https://qa.mandriva.com/show_bug.cgi?id=57010
> For reference relating to comment 12:
> First introduced the above 4 fixes.
> included 7b3a177
> included ed69c6a
> Is there something more that needs done?

Thanks for feedback. Please, provide debug information:


Use 101 or 29 values for xrun_debug and try to put ksyslog messages 
to a relation with the audiable problems.


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

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