Created attachment 41162 [details] xorg log System Environment: -------------------------- Arch: x86_64 Platform: 965gm Libdrm: (master)2.4.23 Mesa: (7.10)7db3e66ba8b8befd1944501edcea785dde30e435 Xserver: (server-1.9-branch)xorg-server-1.9.3-2-ge1e37ef7eb72fb4dfd8cefa1933e406231558d9d Xf86_video_intel: (master)2.13.902-1-g71af40a75fbdd1054b1111e8cbe67ad1f97e6613 Kernel: (drm-intel-fixes) 448f53a1ede54eb854d036abf54573281412d650 Bug detailed description: ------------------------- This issue happens on changing low resolution to high. It doesn't happen on changing high resolution to low. When backlight dimmed, "cat /sys/class/backlight/acpi_video0/brightness" shows the brightness value is not changed. Reproduce steps: ---------------- 1. xinit& 2. xrandr --output LVDS1 --mode 640x480 3. xrandr --output LVDS1 --mode 800x600 4. xrandr --output LVDS1 --mode 1024x768 5. xrandr --output LVDS1 --mode 1280x800
Seems to be working on my t61, though this was with -next and not -fixes: =0 crestline:~$ sudo X -ac -noreset & ... =0 crestline:~$ cat /sys/class/backlight/acpi_video0/brightness 10 =0 crestline:~$ xrandr -d :0 --output LVDS1 --mode 640x480 =0 crestline:~$ cat /sys/class/backlight/acpi_video0/brightness 10 =0 crestline:~$ xrandr -d :0 --output LVDS1 --mode 800x600 =0 crestline:~$ cat /sys/class/backlight/acpi_video0/brightness 10 =0 crestline:~$ xrandr -d :0 --output LVDS1 --mode 1024x768 =0 crestline:~$ cat /sys/class/backlight/acpi_video0/brightness 10 =0 crestline:~$ xrandr -d :0 --output LVDS1 --preferred =0 crestlinecat /sys/class/backlight/acpi_video0/brightness 10 =0 crestline:~$ xrandr -d :0 --output LVDS1 --mode 640x480 =0 crestline:~$ cat /sys/class/backlight/acpi_video0/brightness 10
Oh, and the backlight remains on. ;-)
Any better with drm-intel-fixes? commit 47356eb67285014527a5ab87543ba1fae3d1e10a Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Tue Jan 11 17:06:04 2011 +0000 drm/i915/panel: Only record the backlight level when it is enabled By tracking the current status of the backlight we can prevent recording the value of the current backlight when we have disabled it. And so prevent restoring it to 'off' after an unbalanced sequence of intel_lvds_disable/enable. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=22672 Tested-by: Alex Riesen <raa.lkml@gmail.com> Tested-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: stable@kernel.org
The problem still exits with current drm-intel-fixes tip(22ab70d3262ddb6e69b3c246a34e2967ba5eb1e8).
I hope this was fixed with the removal of the legacy backlight interface, which seemed to be the source of the trouble: commit 951f3512dba5bd44cda3e5ee22b4b522e4bb09fb Author: Indan Zupancic <indan@nul.nu> Date: Thu Feb 17 02:41:49 2011 +0100 drm/i915: Do not handle backlight combination mode specially
Verified with Kernel(drm-intel-fixes) 467cffba85791cdfce38c124d75bd578f4bb8625.
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