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 + via_dmapos_patch=1
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?