On Fri, 15 May 2015, Mario Kleiner <mario.kleiner.de@xxxxxxxxx> wrote: > Hi all, > > since Linux 4.0 i experience some massive display flicker problem on my > Intel HD Ironlake mobile (2010 MacBookPro6,2) under Waylands reference > compositor Weston. > > - Only happens on Linux >= 4.0 on intel-kms with the Intel HD, not under > nouveau-kms with the discrete NVidia gpu. Strangely on Linux 4.1-rc it > happens all the time, whereas on Linux 4.0 it can work normally for > quite a while, but once the problem starts only a reboot can cure it. > > - Almost only happens on Weston, but only very rarely under the XServer. > VT switching from Weston to XOrg makes the problem disappear, switching > back to Weston and it starts again immediately. > > - Only happens if a hardware cursor is displayed - hiding the cursor > stops the flicker immediately, showing the cursor starts the flicker. > > - The drm and desktop is completely idle during this - drm.debug=15 > shows no activity while this happens. > > Symptom: > > Up to the scanline where the cursor is located, the desktop image is > displayed, but jumps horizontally left and right by some random number > of pixels, maybe in the range 0 - 200 pixels with high frequency, making > the content unreadable. Starting with the scanline where scanout of the > cursor starts, the display goes blank, as if some display controller > fifo would underflow and the controller blanks the display in response. > Seems having to scanout the cursor plane in addition to the primary > plane is just enough to push it over some limit? > > I also see cpu and pch pipe a fifo underruns reported by the underflow > irq handlers. > > I saw there were many changes around Linux 4.0 in the kms driver wrt. > watermark calculations, so this might be related? Please try http://patchwork.freedesktop.org/patch/49314 and report back. BR, Jani. > > thanks, > -mario > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
