At Wed, 24 Sep 2008 02:19:54 +0200, Lennart Poettering wrote:
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?
The DMA position handling on some HD-audio hardware is unstable. This could be a reason.
The latest 2.6.27-rc* kernel has a few workarounds for such. Give it a try.
Takashi