On Tue, Aug 02, 2016 at 10:00:12AM +0200, Daniel Vetter wrote: > On Tue, Aug 2, 2016 at 4:26 AM, Linus Torvalds > <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > On Mon, Aug 1, 2016 at 9:32 PM, Dave Airlie <airlied@xxxxxxxx> wrote: > >> > >> This is the main drm pull request for 4.8, I'm down with a cold at the moment > >> so hopefully this isn't in too bad a state, I finished pulling stuff last > >> week mostly (nouveau fixes just went in today), so only this message should > >> be influenced by illness. Apologies to anyone who's major feature I missed :-) > >> > >> i915: > >> BXT support enabled by default > >> GVT-g infrastructure > >> GuC command submission and fixes > >> BXT workarounds > >> SKL/BKL workarounds > >> Demidlayering device registration > >> Thundering herd fixes > >> Missing pci ids > >> Atomic updates > > > > Hmm. I did the merge and pushed it out, but testing it on my laptop > > shows some very annoying flickering problem. > > > > The screen goes dark for a very short while (one frame? Who knows? > > Seems longer occasionally). I have no idea what triggers it, but it > > happens quite a lot when it happens. Like once every second or two. > > And it seems to happen most of the time, although right now it happens > > to be behaving nicely, so sometimes it goes for a while without the > > flickering. > > > > Things *work*, but the flickering is nasty enough to make the end > > result painful to use. > > > > The only thing I see in dmesg that looks bad is > > > > [drm:intel_set_cpu_fifo_underrun_reporting [i915]] *ERROR* > > uncleared fifo underrun on pipe A > > [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A > > FIFO underrun > > > > but I've seen that before, and it happens a couple of times during > > boot. Not once per second. > > > > This is my old Vaio 11 Pro, now running Fedora 24 (up-to-date as of today). > > > > So it's bog-standard intel graphics (i5-4200U - Haswell ULT). > > > > Suggestions to try? > > psr or fbc are the likely culprits. More likely fbc if the underruns > correlate with the flicker (but note that by default we only report > them once per modest, needs to be reset with a dpms or > suspend/resume). Driver should even pick up the new module option > settings at runtime (but again you need to force a modeset, just > suspend/resume quickly), so fast to test. I think FBC is still disabled by default on HSW. So PSR seems more likely. The underruns might point at some watermark fail though :( I have a couple of pending PSR patches you may want to try as well, if i915.enable_psr=0 helps. First set is here: git://github.com/vsyrjala/linux.git psr_setup_time_2 This should be perfectly safe to go in actually, as it will only result in disabling PSR with certain panels. The second set is here: git://github.com/vsyrjala/linux.git psr_fixes_2 This one I think is causing some kind of slight regression on one machine in our CI system. Still not sure what's going on there. -- Ville Syrjälä Intel OTC _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
