On Fri, Oct 11, 2013 at 12:50 PM, Alex Deucher alexdeucher@gmail.com wrote:
On Fri, Oct 11, 2013 at 12:33 AM, Ilia Mirkin imirkin@alum.mit.edu wrote:
I was just looking at https://bugs.freedesktop.org/show_bug.cgi?id=20341 (see last comment). Basically he's able to to use the card with agpmode=2 but not the auto-detected agpmode=4. I also saw that the radeon driver has a large quirks list, and it seems silly to reproduce it in nouveau.
However the quirks in the radeon driver are a bit odd -- they are per agp chipset/card chipset pair, rather than a blanket max speed for the whole agp chipset. I find this surprising, but I suppose I don't know that much about all this stuff. I was thinking for nouveau, it would just be at the agp chipset level.
Do you guys think that it's reasonable to make the quirks list dependent on the agp chipset only? In that case, I can refactor and create The One True List (tm). Otherwise I'll just hack something into nouveau inspired by the radeon list. [Also for the single list, it might be better for the agpgart driver itself to know about the restrictions, but that's probably more refactoring than I care for.]
Comments/suggestions/concerns appreciated.
It's very much dependent on combinations of gpus and chipsets in my experience. One could probably distill down the actual quirks to some general chipset or GPU specific ones, but unfortunately AGP is getting so old now that errata lists for old chipsets and GPUs are probably hard to come by. I don't foresee any new AGP systems any time soon, so I'm not sure it's worth putting too much effort into it.
OK, so it sounds like the way forward is for me to compile a chipset -> maxspeed map for nouveau to use and leave radeon out of it. Ben/David -- does that sound acceptable to you guys? Basically I'd take the radeon list's chipsets and apply those maxima to all nouveau video cards (overridable with agpmode, of course).
-ilia