Environment: -------------------------- Kernel: drm-intel-testing commit 95d42e7d341861132ffec806328dd7fc85516995 Merge: cf8f3ba 2a0a016 Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Fri Dec 13 17:57:43 2013 +0100 Merge remote-tracking branch 'origin/topic/core-stuff' into drm-intel-nightly Bug detailed description: ----------------------------- Flicker screen while testing testdisplay -f 38.25,800,832,912,1024,600,603,607,624 It occurs on 1 machine(total test on 3 machines).It's first time to run display test on this machine, and we didn't find good point. Steps: --------------------------- ./testdisplay -f 38.25,800,832,912,1024,600,603,607,624
The testing runs on 2 pipe mode(eDP+VGA) and the flicker screen shows on VGA screen. If only pluged VGA, flicker screen will doesn't shown.
Can you please attach a debug dmesg here? Also a short video of the flickering might help.
Created attachment 90849 [details] dmesg
(In reply to comment #2) > Can you please attach a debug dmesg here? > > Also a short video of the flickering might help. Please check the dmesg in attachment. About video, It's bigger than the attachment limit, I upload it on youtube, here is the link: http://youtu.be/NXzOA9Ye208
Is the 800x600 mode the only one that flickers like this? I presume it works well on other machines, but with the same monitor (just to rule out an issue with the screen)? Video looks like pipe underruns or some other clock instability.
(In reply to comment #5) > Is the 800x600 mode the only one that flickers like this? > > I presume it works well on other machines, but with the same monitor (just > to rule out an issue with the screen)? > > Video looks like pipe underruns or some other clock instability. Yes, Only 800x600 mode has this issue, it works well on 1024x768 mode. We doesn't find this issue on other machines(HSW BDW) This issue occurs on HDMI output too, plese refer to https://bugs.freedesktop.org/show_bug.cgi?id=72751
Hm, sounds like the PLL is a bit unstable at that dotclock. Jesse, can you try to escalate to hw guys?
I checked on latest -nightly(e5ad48d0d4f08e5db537901a2d7b2f0750ddd88c), This bug unable to reproduce.
Closing old verified.
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