https://bugzilla.novell.com/show_bug.cgi?id=308264#c33 Adam Martinson <loki1984@vfemail.net> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |loki1984@vfemail.net --- Comment #33 from Adam Martinson <loki1984@vfemail.net> 2007-10-08 15:56:31 MST --- Add the X41 Tablet to the list (technically the first Lenovo Thinkpad). For me, Fn+Home/End always works for changing the brightness, but thinkpad_acpi, and consequently kpowersave, etc have problems with it. After installation kpowersave claimed controlling brightness was not supported for my hardware, and indeed the /proc/acpi/ibm/brightness and /sys/class/backlight/thinkpad_screen interfaces were missing. grep thinkpad_acpi /var/log/boot.msg produced: <6>thinkpad_acpi: ThinkPad ACPI Extras v0.14 <6>thinkpad_acpi: http://ibm-acpi.sf.net/ <6>thinkpad_acpi: ThinkPad BIOS 75ET35WW (1.06 ), EC 75HT18WW-1.00 <6>thinkpad_acpi: IBM ThinkPad X41 Tablet <3>thinkpad_acpi: CMOS NVRAM (5) and EC (0) do not agree on display brightness level It seems that Fn+Home/End use the NVRAM interface, and this works even in the BIOS before the OS is loaded. If you make a note of the EC setting, reboot, and before the OS loads, use Fn+Home/End to make the NVRAM setting match the EC setting, then the thinkpad_acpi module will load without errors. You can also use Fn+Home/End to change the brightness to the same level as the EC on a running system, and then reinsert the thinkpad_acpi module. After this the /sys and /proc interfaces will be there, and everything works fine until you use Fn+Home/End to change the brightness. As soon as you do, cat /proc/acpi/ibm/brightness returns: level: unreadable cat /sys/class/backlight/thinkpad_screen/actual_brightness returns: -5 If you use Fn+Home/End to change it the brightness back, then you can use the /proc and /sys interfaces again, and everything works normally. Using the /proc and /sys interfaces to control the brightness properly updates both the NVRAM and EC, but Fn+Home/End only update the NVRAM. Hopefully this info is helpful. ~Loki -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.