Kernel Bug Tracker – Bug 28942
no more brightness control on Fujitsu-Siemens SI 2636 laptop with 2.6.38-RC4 kernel
Last modified: 2011-04-26 02:24:32 UTC
Created attachment 47512 [details]
dmidecode Fujitsu-Siemens SI2636
First thank you for your great work on linux an make all this possible.
After compiling a 2.6.38-RC4 kernel i found that the brightness control
off my laptop Fujitsu-Siemens SI 2636 don't work anymore.
The brightness control work with the fn+F8 an fn+F9 keys with all
previous version off the kernel i tried from 2.6.24 to 2.6.37 .
My system is Kubuntu 10.04 LTS with the kernel mode-settings and the
intel video driver.
In the dmesg output off the 2.6.37 kernel i found 2 related lines :
[Firmware Bug]: ACPI: No _BQC method, cannot determine initial brightness
[drm:intel_panel_get_max_backlight] *ERROR* fixme: max PWM is zero.
But even with those errors the brightness control work fine with the
When using the 2.6.38-RC4 kernel i found that the directory
/sys/class/backlight is empty.
Attached is dmidecode.
If you need more info just tell me
Created attachment 47522 [details]
Created attachment 47532 [details]
Created attachment 47542 [details]
Created attachment 47552 [details]
Fujitsu-Siemens SI2636 dsdt.dsl
Does the patch from bug #27702 help?
The patch is perfect. The keys for brightness control works again.
thanks for testing
*** This bug has been marked as a duplicate of bug 27702 ***