thinkpad brightness controls reversed (please implement fix from fedora dudes)

[Gary Trakhman]

Binary package hint: linux-image

brightness steps are reversed as reported by lshal. This causes the Fn-Home and Fn-End buttons to work in reverse, and the brightness increases on idle, etc. The link below has a patch to fix video.c in the kernel, it will implement a sort on the brightness values. Please implement this for us ubuntu users and help push it up to the linux kernel.

https://bugzilla.redhat.com/show_bug.cgi?id=470465

gary@gary-laptop:~$ cat /proc/acpi/video/VGA/LCDD/brightness
levels: 100 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20
current: 25

I have a thinkpad SL300 with intel GM45 graphics.

[Andy Whitcroft (apw)]

Was http://bugzilla.kernel.org/show_bug.cgi?id=12037 which was marked duplicate of this bug

[Andy Whitcroft (apw)]

Could you test the kernels at the URL below, it seems that some BIOSen have bad ACPI brightness interfaces which will now be being used, this kernel should detect and ignore these. It would be good to know if this fixes your issues:

    http://people.ubuntu.com/~apw/lp311716-intrepid/

This is the fix proposed in comment 34 of the linked upstream bug.

[Wouter Stomp (wouterstomp-deactivatedaccount)]

With that kernel the brightness hotkeys dont do anything at all anymore (although I tested on Jaunty, not Intrepid). I also have the sl300 with intel GM45 graphics.

[Gary Trakhman (gary-trakhman)]

latest 2.6.28-5 brings back the reversed keys, whereas in 2.6.28-4 and before I couldn't do anything brightness related once the kernel boots.

[Wouter Stomp (wouterstomp-deactivatedaccount)]

As this isn't fixed while bug 311716 (of which this one was reported as a duplicate) is fixed, and looking at the upstream bugreport, this seems to be a different issue. Marked as not a duplicate.

[Nick Booker (nmbooker)]

My results on Intrepid...

I installed apw's kernel on an SL300 type 2738-53G running Intrepid, and it disabled brightness adjustment completely, both with keys and with the Gnome brightness applet.

empo@ubuntu:~$ cat /proc/acpi/video/VGA/LCDD/brightness
<not supported>

The current Intrepid kernel has reversed brightness keys.

Going for lunch now...

[Wouter Stomp (wouterstomp-deactivatedaccount)]

This is fixed in lucid.