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View Full Version : [ubuntu] 2.6.27-11-generic upgrade broke screen brigtness controls on thinkpad x61t



freedryk
January 29th, 2009, 07:59 PM
Subject says it all--I upgraded to 2.6.27-11-generic on my thinkpad x61t and now the screen brightness doesn't change. Ubuntu registers the keys--the screen brightness bar pops up when I hit the key and I can move the screen brighness bar up and down, but the screen brightness doesn't change. Any ideas?

zerted
January 30th, 2009, 07:34 AM
I have the same laptop and the same problem. I also have the repeat installation issue described here: http://ubuntuforums.org/showthread.php?t=1047919

I've been booting into 2.6.27-9 in order to reduce the brightness.

yipperzz
January 30th, 2009, 11:14 PM
i am having issues with my brightness on my t500 after the new updates. it keeps resetting itself after reboot. i've never had this problem before?

zackiv31
January 31st, 2009, 12:15 AM
X61 tablet here...just booted into same new kernel and can't change brightness...

thehero
January 31st, 2009, 01:58 AM
Same happened to me after an upgrade on a t60 today. The upgrade broke all the fn key combos and the middle mouse button scroll.

earthtux
February 2nd, 2009, 05:06 PM
mine is x61t got the same problem
anyone knows how to manually fix this problem?
thx!

diego_dambra
February 4th, 2009, 10:28 PM
Try adding:
options thinkpad_acpi brightness_enable=1

to file:
/etc/modprobe.d/options

Otherwise try some of the other suggestions in:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/311716

r.anger
February 4th, 2009, 10:46 PM
same problem here.
i guess these are relevant changes to thinkpad-acpi:


--- linux-2.6.27.orig/drivers/misc/thinkpad_acpi.c
+++ linux-2.6.27/drivers/misc/thinkpad_acpi.c
@@ -4921,16 +4921,25 @@
*/
b = tpacpi_check_std_acpi_brightness_support();
if (b > 0) {
- if (thinkpad_id.vendor == PCI_VENDOR_ID_LENOVO) {
- printk(TPACPI_NOTICE
- "Lenovo BIOS switched to ACPI backlight "
- "control mode\n");
- }
- if (brightness_enable > 1) {
- printk(TPACPI_NOTICE
- "standard ACPI backlight interface "
- "available, not loading native one...\n");
- return 1;
+
+ if (acpi_video_backlight_support()) {
+ if (brightness_enable > 1) {
+ printk(TPACPI_NOTICE
+ "Standard ACPI backlight interface "
+ "available, not loading native one.\n");
+ return 1;
+ } else if (brightness_enable == 1) {
+ printk(TPACPI_NOTICE
+ "Backlight control force enabled, even if standard "
+ "ACPI backlight interface is available\n");
+ }
+ } else {
+ if (brightness_enable > 1) {
+ printk(TPACPI_NOTICE
+ "Standard ACPI backlight interface not "
+ "available, thinkpad_acpi native "
+ "brightness control enabled\n");
+ }
}
}

diff from 2.6.27-10.20 to 2.6.27-11.21 ( http://launchpadlibrarian.net/20551423/linux_2.6.27-10.20_2.6.27-11.21.diff.gz )

however i have no idea what this actually means and how to resolve the problem.
i filed this bug at launchpad: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/325491

r.anger
February 6th, 2009, 08:00 PM
my reported turned out to be a duplicate...
see https://bugs.launchpad.net/bugs/313231 for workarounds

earthtux
February 11th, 2009, 07:45 AM
Try adding:
options thinkpad_acpi brightness_enable=1

to file:
/etc/modprobe.d/options

Otherwise try some of the other suggestions in:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/311716

thx man!
the one u suggested works
but now my sound hotkey brokes LOL
could you please help me again?thx
woot

zerted
February 22nd, 2009, 09:46 AM
Thanks, that worked for me too. Though, my sound buttons still work.