At Sun, 11 Apr 2010 21:25:16 +0100, Ben Hutchings wrote:

[1 <text/plain; UTF-8 (quoted-printable)>] [Earlier messages can be found at http://bugs.debian.org/536896 ]

On Mon, 2010-04-12 at 01:08 +0800, James Andrewartha wrote:

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On Thu, 25 Feb 2010, Moritz Muehlenhoff wrote:

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On Tue, Jul 14, 2009 at 09:57:54PM +0800, James Andrewartha wrote:

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Package: linux-image-2.6.26-2-amd64 Version: 2.6.26-17 Severity: normal

All audio from gstreamer-using apps (eg Totem and Banshee) pops when I use a 2.6.{25,26,28,30} amd64 kernel and i386 userspace. 2.6.24-etchnhalf.1-amd64 does not have this problem, nor does 2.6.26-2-686. It doesn't occur when using non-gstreamer apps like mplayer or mpd, nor with various gst-launch pipelines suggested by #gstreamer like gst-launch playbin uri=file:///home/trs80/a.mp3

Hi, The next release of Debian (6.0, code name Squeeze) will be based on 2.6.32. Please test the current 2.6.32 from unstable/testing and tell us whether the problem persists. If so, we should report it upstream to the kernel.org developers.

The 2.6.32 kernel is available from packages.debian.org and can be installed in both Debian stable, testing and unstable installations.

I've bisected it, and the bad patch is 130755108ba03461f69da990e54e02a254accd23:

Thanks for taking the time to do this.

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Author: Takashi Iwai tiwai@suse.de 2008-01-09 02:08:14 Committer: Jaroslav Kysela perex@perex.cz 2008-02-01 01:29:47 Parent: d948035a928400ae127c873fbf771389bee18949 ([ALSA] Remove PCM xfer_align sw params)

[ALSA] PCM - clean up snd_pcm_lib_read/write

Introduce a common helper function for snd_pcm_lib_read and snd_pcm_lib_write
for cleaning up the code.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

I don't know anything about this code, but I'm happy to deal with upstream if you'd prefer me to.

The above commit is supposed to be cleanup, but it has at least one semantic change: snd_pcm_mmap_control::avail_min no longer applies to non-blocking file handles. I don't know whether this is was an intentional or unintentional change, but it wasn't commented. I also don't know whether this can explain the popping, but I expect that it has changed the timing of audio I/O.

The above change is essentially a fix of the buggy behavior for non-blocking access. avail_min is the definition for wake-up behavior, and it doesn't define the blocking behavior. But, it's possible that this changes the timing, indeed. If so, it implies that the app expects somehow wrongly.

thanks,

Takashi