Bug 104041

Summary: 4.2 kernel: many *ERROR* mismatch in has_drrs
Product: Drivers Reporter: Takashi Iwai (tiwai)
Component: Video(DRI - Intel)Assignee: intel-gfx-bugs (intel-gfx-bugs)
Status: RESOLVED CODE_FIX    
Severity: normal CC: intel-gfx-bugs
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 4.2 Subsystem:
Regression: No Bisected commit-id:
Attachments: dmesg output

Description Takashi Iwai 2015-09-04 14:10:42 UTC 
Created attachment 186721 [details]
dmesg output

This originates from another bug 104001.

4.2 kernel spews many kernel warnings on HP EliteBook 940 G1 laptop with Haswell chip.

At booting:

[    5.205358] [drm:intel_pipe_config_compare [i915]] *ERROR* mismatch in has_drrs (expected 1, found 0)
[    5.205361] ------------[ cut here ]------------
[    5.205387] WARNING: CPU: 3 PID: 76 at drivers/gpu/drm/i915/intel_display.c:12691 intel_modeset_check_state+0x5a4/0x870 [i915]()
[    5.205388] pipe state doesn't match!

At plugging DP on dock (MST):

[   33.096865] [drm:intel_pipe_config_compare [i915]] *ERROR* mismatch in has_drrs (expected 1, found 0)
[   33.096876] ------------[ cut here ]------------
[   33.096916] WARNING: CPU: 3 PID: 988 at drivers/gpu/drm/i915/intel_display.c:12691 intel_modeset_check_state+0x5a4/0x870 [i915]()
[   33.096919] pipe state doesn't match!
....
[   33.230467] WARNING: CPU: 3 PID: 988 at drivers/gpu/drm/i915/intel_display.c:6330 intel_modeset_check_state+0x112/0x870 [i915]()
[   33.230472] attached crtc is active, but connector isn't

At unplugging DP:

[  218.764695] [drm:intel_pipe_config_compare [i915]] *ERROR* mismatch in has_drrs (expected 1, found 0)
[  218.764706] ------------[ cut here ]------------
[  218.764739] WARNING: CPU: 3 PID: 988 at drivers/gpu/drm/i915/intel_display.c:12691 intel_modeset_check_state+0x5a4/0x870 [i915]()
[  218.764741] pipe state doesn't match!

Note that this is the patched kernel based on vanilla 4.2 and pulling drm-intel-next-fixes (commit 4e3d1e26c2b2c40ebff69f2825fa862bfcf082d1).
Comment 1 Jani Nikula 2015-10-07 11:25:17 UTC 
Presumed fixed upstream, closing.

If the problem persists with latest kernels, please file a bug at the freedesktop.org bugzilla [1], referencing this bug. Thank you.

[1] https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&component=DRM/Intel