Created attachment 112731 [details] dmesg System Environment: -------------------------- Kernel: (drm-intel-next-queued)92e76c8c7e436a07af3e0b594480ff8689add078 Some additional commit info: Author: Ville Syrjälä <ville.syrjala@linux.intel.com> Date: Mon Oct 21 19:01:58 2013 +0300 drm/i915: Clamp cursor coordinates to int16_t range Bug detailed description: ----------------------------- Everytime when the computer boot up into operating system, its eDP monitor will turn into black and its brightness is zero. But in the BIOS stage, the monitor works well. After the machine boot up, we can change the brightness with the function keys(Fn+F11),or we can also change the value of brightness in file (/sys/class/backlight/intel_backlight/brightness) .Then the monitor will work normally. Reproduce steps: ----------------------------- 1.boot up the machine 2.cat /sys/class/backlight/intel_backlight/brightness
Created attachment 112741 [details] acpidump This is the acpidump.
Created attachment 112851 [details] Fix initial level validity test There are two patches, this is patch 1. Apply on top of Rafael's linux-next branch: http://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
Created attachment 112861 [details] Quirk initial backlight level 0 This is patch 2, used to quirk initial backlight level 0 problem. Apply on top of patch 1.
Qingshuai handed me the idealpad u330p and I did the test, everything works now with the two above patches applied. Alternatively, the system can be quirked to use native backlight as it is also a win8 system with Intel graphics card.
It works great on my Lenovo Ideapad Z510. Thanks. Hope -stable kernel can backport patch soon.
commit 2c62333a408f5badd2d2ffd7177f95deeccc5ca4 Author: Aaron Lu <aaron.lu@intel.com> Date: Wed Nov 6 09:07:10 2013 +0800 ACPI / video: Quirk initial backlight level 0 Entered Linus' tree.