[alsa-devel] via_dmapos_patch

David Henningsson david.henningsson at canonical.com
Wed Sep 29 10:14:49 CEST 2010

I'm researching a few bugs where the user claims position_fix=1 helps 
the problem, but adding the quirk for that model surprisingly didn't. So 
looking at the code, I concluded that the difference was 
via_dmapos_patch, and that they all had via_dmapos_patch=1, and that 
via_dmapos_patch=0 helped them solve the problem. Three out of five (not 
all of them have reported back on via_dmapos_patch=0 yet) are VIA 
controllers rev 10.

So we now have VIA controllers that need via_dmapos_patch=0.

I can think of a few approaches here:

1) since position_fix=1 implicitly sets via_dmapos_patch to 0 (maybe 
unintentionally), we should add a position_fix=3 meaning lpib + 

2) figure if something has changed recently (as in "within the last 
year"...) that has made via_dmapos_patch=1 work worse than before

3) figure out if there are several ATI/VIA controllers that actually 
never wants the patch.

Any thoughts?

David Henningsson, Canonical Ltd.

More information about the Alsa-devel mailing list