|Summary:||i915: screen goes dark on modeswitch during boot (Failed to own the pwm chip)|
|Component:||DRM/Intel||Assignee:||Intel GFX Bugs mailing list <intel-gfx-bugs>|
|Status:||CLOSED DUPLICATE||QA Contact:||Intel GFX Bugs mailing list <intel-gfx-bugs>|
|i915 platform:||BYT||i915 features:||display/backlight|
Description sassmann 2017-05-19 06:09:40 UTC
Created attachment 131413 [details] dmesg with debug enabled With 4.12-rc1 the screen goes dark during boot when attempting to modeswitch. I assume the backlight is turned off. Still worked with kernel 4.11. This is on a baytrail tablet.
Comment 1 Jani Nikula 2017-05-30 12:22:03 UTC
Bisect would really be helpful here.
Comment 2 sassmann 2017-05-31 09:57:37 UTC
Indeed it would, but doing a full bisect takes way too long to compile and test. If you have a list of commits that went into 4.12-rc1 and might be relevant to test I can do a few builds and try those.
Comment 3 sassmann 2017-05-31 15:20:08 UTC
Created attachment 131605 [details] dmesg 4.12-rc3 display on I tried the 4.12-rc3 to check if anything has changed. Screen still goes dark most of the time. However maybe 1 in 5 boots the screen stays on with full brightness. So this might be a race. Attaching another dmesg of a successful boot with screen staying on.
Comment 4 Jani Nikula 2017-06-02 09:22:48 UTC
Did your kernel config change? Possibly dupe of bug 96571. I believe that might manifest itself as a race too.
Comment 5 sassmann 2017-06-02 09:36:21 UTC
kernel config stayed the same, no change there. Any way for me to confirm if this is indeed a dupe of bug 96571? I have CONFIG_PWM_LPSS=m CONFIG_PWM_LPSS_PCI=m CONFIG_PWM_LPSS_PLATFORM=m Also any patches I could test on top of 4.12? I see a lot of patch references in the other bz but not sure what's relevant.
Comment 6 Jani Nikula 2017-06-02 10:04:14 UTC
Set config options >CONFIG_PWM=y >CONFIG_PWM_CRC=y >CONFIG_I2C_DESIGNWARE_PLATFORM=y >CONFIG_I2C_DESIGNWARE_PCI=y >CONFIG_INTEL_SOC_PMIC=y >CONFIG_DRM_I915=m and see if it helps.
Comment 7 sassmann 2017-06-02 11:24:55 UTC
The only difference to my config was that I had CONFIG_I2C_DESIGNWARE_PLATFORM=m CONFIG_I2C_DESIGNWARE_PCI=m instead of =y. However changing those to =y didn't make a difference. Would any intel-gpu-tools output be useful?
Comment 8 Jani Nikula 2017-07-04 13:47:16 UTC
Seeing your comment in bug 96571, can we assume this is a dupe?
Comment 9 sassmann 2017-07-04 15:57:25 UTC