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  1. Bug #741825
  2. Comment #16

Comment 16 for bug 741825

Revision history for this message
David Henningsson (diwic) wrote : Should we really use POS_FIX_VIACOMBO for AMD/ATI chipsets?

I'm far from sure, but I could be on to something...

Looking at the code for azx_via_get_position, it seems that for
recording streams, it accesses a register at position
VIA_IN_STREAM0_FIFO_SIZE_OFFSET = 0x90. Looking at the datasheet for
SB700, that register is not even present. This does not seem right to me.

Could it be that we should use POS_FIX_LPIB by default for AMD/ATI
chipsets instead? It seems more reasonable to me.
In addition, I looked through some of the commits for quirking to
POS_FIX_LPIB and the four I checked were all ATI chipsets.

So; I've tried adding:
options snd-hda-intel position_fix=1
to /etc/modprobe.d/alsa-base.conf

...to my machine with the infamous [1002:4383] controller (and
rebooted), and the few times I've tested, recording worked successfully
with pulseaudio. So could you please follow this up with testing on your
machines to see if we have actually managed to solve this long-standing bug?

The only annoying thing is that I didn't realise this earlier :-/

--
David Henningsson, Canonical Ltd.
http://launchpad.net/~diwic