W dniu 26.07.2011 23:14, Colomban Wendling pisze:

Hi,

Following a bug report started in Debian BTS, in bug 635362 [1], I was asked to post here after testing upstream kernels and reproducing the bug.

So, here's the problem: my HDA audio chip [2] started to output very choppy sound with Linux kernel 3.0, while it worked perfectly well in previous versions -- latest two I used being 2.6.38 and 2.6.39 from Debian. Please note that simply booting on 2.6.39 works as usual, so it's IMHO definitely a driver regression.

I tried Debian's 3.0 as well as mainline 3.0 and git5 snapshots, and all 3 were affected by the problem -- though the kernel log isn't exactly the same.

I attach three dmesg outputs, always took after trying to play a sound (and hearing it choppy, it happens every time):

dmesg-3.0.0-mainline: dmesg when running 3.0 mainline dmesg-3.0.0-git5: when running 3.0-git5 snapshot dmesg-3.0.0-git5-2: same as dmesg-3.0.0-git5 but configured without CONFIG_SND_HDA_ENABLE_REALTEK_QUIRKS (doesn't change anything)

If you want to see dmesg from the 2.6.39 kernel (where sound works well) or Debian's 3.0, see respectively [3] and [4].

Thanks by advance, and if you need any further details or testing, please let me know.

Regards, Colomban

[1] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=635362 [2] Realtek ALC889 on an MSI H55M-E33, see lspci in Debian bug [1] for details [3] http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=15;filename=dmesg-2.6.39-2-... [4] http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=15;filename=dmesg-3.0.0-1-a...

I am probably wrong, but did you try setting CONFIG_SND_HDA_BUFFER_SIZE to a larger value?

Julian