[alsa-devel] Something wrong with snd_pcm_avail_update

Heya!

There seems to be something wrong with snd_pcm_update_avail() for mmap in recent 2.6.26 kernels:

Quoting Alexander Gavrilov:

<snip> Fedora 9 with kernel 2.6.26.3-29 exhibits a bug where the driver decrements its hw.ptr under certain stress conditions, or at least it appears so from debugging.

It causes alsa-lib to give absurdly huge avail numbers to pulseaudio, which crashes it. This patch adds a work-around to avoid such unfriendly behavior until the bug is fixed.

As this is not a real fix, it displays a message every time it is activated. </snip>

https://bugzilla.redhat.com/show_bug.cgi?id=462200

(see the patch attached to that bug report)

Takashi, Jaroslav, do you know anything about this?

Lennart