On 01/10/2012 08:44 PM, Keith Packard wrote: > On Tue, 10 Jan 2012 16:51:08 -0800, Eric Anholt <eric at anholt.net> wrote: > >> So they've gone out of their way to build broken stuff. Awesome. > > Well, in theory, the interrupt would be generated *before* the hardware > goes to RC6; when idle, I'm not exactly sure what the hardware would be > doing to generate interrupts. That's right. I think we need to think about the programming sequence a bit more. The GT should be smart enough to not sleep if it has any work pending that may generate interrupts. I don't think this by itself explans anything. > >> I'd say you've found the clue here -- I'm a lot happier with going with >> your patches now (and I was pretty happy with the gen7 side before). >> I'd just like to not mess with gen6 unless we've got missed irq bugs >> there to fix. > > Yeah, knowing that there might be interrupt funnies due to RC6 goes some > way to explaining why just avoiding RC6 helps. > > I wonder if any of this might explain the RC6 issues we see on SNB on > some hardware, and whether we should give this a try... I know, grasping > at straws, but still, it's about all we have at this point. > Just as a reminder, never going into rc6 never fixed any problems, so I still believe this is somehow timing related. ~Ben the pessimist
