Bug 96277

Summary: laptop display blinks with kernel 4.6.0 (regression)
Product: DRI Reporter: Christian Boltz <freedesktop>
Component: DRM/IntelAssignee: Dhinakaran Pandiyan <dhinakaran.pandiyan>
Status: CLOSED DUPLICATE QA Contact: Intel GFX Bugs mailing list <intel-gfx-bugs>
Severity: major    
Priority: medium CC: dhinakaran.pandiyan, intel-gfx-bugs, rodrigo.vivi, tiwai
Version: XOrg git   
Hardware: Other   
OS: Linux (All)   
i915 platform: HSW i915 features: display/PSR

Description Christian Boltz 2016-05-30 16:29:14 UTC
I'm using openSUSE Tumbleweed (rolling release) and the kernel from Kernel:Stable (actually with two small AppArmor patches on top) so I already have kernel 4.6.0 instead of the 4.5.4 kernel in Tumbleweed.

uname -r: 4.6.0-4.gaf7ce24-default
uname -m: x86_64

I'm using a laptop (Tuxedo Book BC1703 with i7-4710MQ CPU) with intel graphics and two screens (laptop display + external screen via HDMI), but also see this bug when the external screen is disconnected.

Kernel 4.6.0 causes the laptop screen to blink / flicker as soon as X starts (both login manager and in KDE) which makes the laptop display unusable and hurts in the eyes. This blinking is also reproducable with "X -retro".

I can "fix" this by booting 4.5.4, so this is clearly a regression in 4.6.0.

Also, booting kernel 4.6.0 with i915.enable_psr=0 stops the blinking.

Reproducable: always (the blinking with 4.6.0 without boot parameters, and also the non-blinking with i915.enable_psr=0 or kernel 4.5.4)

I initially reported this bug on 
You can find logs (dmesg with drm.debug=0x0e), hardware details and some other details there.

If you need more information, just ask ;-)
Comment 1 Dhinakaran Pandiyan 2016-06-15 02:07:35 UTC
This looks like https://bugs.freedesktop.org/show_bug.cgi?id=95176 
Can you try 4.7-rc1?
Comment 2 Christian Boltz 2016-06-15 20:38:01 UTC
4.7 rc1 sounds old ;-)  I tried with kernel-default-4.7.rc3-1.1.g59af2d0.x86_64 from the openSUSE Kernel:HEAD repo.

Unfortunately the laptop still blinks with 4.7 rc3 :-(
Comment 3 Dhinakaran Pandiyan 2016-06-16 18:36:34 UTC

*** This bug has been marked as a duplicate of bug 95176 ***
Comment 4 Dhinakaran Pandiyan 2016-06-16 18:38:19 UTC
Hmm.. Can you please try the patches - https://patchwork.freedesktop.org/series/8046/ . It seems to have worked as per - https://bugs.freedesktop.org/show_bug.cgi?id=95176

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