At Thu, 15 Nov 2012 21:22:41 +0100, Takashi Iwai wrote: > > At Thu, 15 Nov 2012 21:07:33 +0100, > Daniel Vetter wrote: > > > > On Thu, Nov 15, 2012 at 6:03 PM, Takashi Iwai <tiwai at suse.de> wrote: > > > Some IVB machines seem to need non-MT forcewake. Using MT forcewake > > > on such machines result in broken or blank screens. > > > > > > Signed-off-by: Takashi Iwai <tiwai at suse.de> > > > --- > > > The commit 36ec8f877481449bdfa072e6adf2060869e2b970 triggered a > > > regression on my test IVY laptops. Instead of reverting the commit, > > > I cooked a bit to make fitting only for IS_IVYBRIDGE(). > > > > Hm, that's rather bad since proper usage of DERRMR requires that we > > enable rc6 on ivb, which is only really possible when we have > > multi-threaded forcewake. > > Hm, so just disabling RC6 doesn't suffice? > > > Now I've thought that all production > > machines have that enabled (it's something the bios should do), so the > > big question: Is this a pre-production hw? If so, a bios upgrade > > should fix it since historically we've killed pre-production > > workarounds once the real hw ships, there are simply too many ... > > Indeed a machine showing the issue is a prototype machine, but it's a > product-ready unit, so I don't think CPU/GPU is different from the > same model in the market. It seems that I've looked at a lspci output on a wrong machine while working remotely. The machines showing the problem have CPU revisions less than 8. So, you are right, it must be specific to a pre-production CPU. Assuming it being not in the market, I can live without that. Time to throw away a crap :) Sorry for the noise. Takashi
