brightness controls on Lenovo Thinkpad x61 broken in linux-image-generic 2.6.27-11.27

[Anna Glasgall]

The brightness controls on my Lenovo ThinkPad x61 (model 7675-CTO) running Ubuntu 8.10 on amd64 are broken in the latest intrepid update kernel (2.6.27-11.27). Neither using g-p-m via the volume fn-keys nor manually manipulating /sys/class/backlight files works.

Brightness controls worked in 2.6.27-9.19, the previous kernel I had installed.

Booting with `acpi_backlight=vendor' as suggested in lp:311716 results in video corruption (diagonal black lines across the screen in X) and still does not fix brightness controls.

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Hi All,

On X61 (type / model : 7673-4NG) the same problem occurs, also after a kernel update.
I am running Ubuntu 8.10, 64-bit. The menu works fine when I hit the brightness keys: the bar goes left and right. However, there is no adjustment to the brightness.