← Back to team overview

mactel-support-community team mailing list archive

Re: Call for Testing: Updated Apple backlight driver

 

Hi Seth,

On Tue, 31 Jan 2012 10:55:34 -0600
Seth Forshee <seth.forshee@xxxxxxxxxxxxx> wrote:

> [Note that I'm not subscribed to the mactel-support-community
> list; please Cc me on any replies]

Noted.

> Hi all,
> 
> I've been doing some work on the Apple backlight driver in the
> Linux kernel to get support for adjusting the screen brightness
> via the gmux device. This will hopefully get working screen
> brightness adjustment for all Macs that that don't currently have
> it. This support has been floating around in various forms for a
> while now, and what I'm trying to do is get it into stock Ubuntu
> so brightness adjustment will work out-of-the box, more or less.
> 
> The driver changes are pretty much complete, and now I'd like to
> get testing on as many different Apple models as possible. If
> you've got a machine with a built-in dispaly and would be willing
> to test, please visit the following page for instructions on how
> you can help.

I updated the wiki page with results from my MacBookPro5,1.
My backlight was working before, with stock Oneiric system, so I am
testing just to make sure the new driver *still* works.

Note that I have no acpi_video device, although the wiki page says
I should have it at a minimum:

    $ ls /sys/class/backlight
    gmux_backlight

    cdb@svelte:/sys/class/backlight/gmux_backlight$ ls -l
    total 0
    -r--r--r-- 1 root root 4096 2012-01-31 09:16 actual_brightness
    -rw-r--r-- 1 root root 4096 2012-01-31 09:16 bl_power
    -rw-r--r-- 1 root root 4096 2012-01-31 09:17 brightness
    lrwxrwxrwx 1 root root    0 2012-01-31 09:16 device -> ../../../00:08
    -r--r--r-- 1 root root 4096 2012-01-31 09:16 max_brightness
    drwxr-xr-x 2 root root    0 2012-01-31 09:16 power
    lrwxrwxrwx 1 root root    0 2012-01-31 09:16 subsystem -> ../../../../../class/backlight
    -r--r--r-- 1 root root 4096 2012-01-31 09:16 type
    -rw-r--r-- 1 root root 4096 2012-01-31 09:16 uevent
    cdb@svelte:/sys/class/backlight/gmux_backlight$ cat max_brightness 
    77978

Backlight adjustment through this gmux_backlight 'brightness' file
works.  My backlight keys on the keyboard don't work, however, so I
assume other changes are required to hook that up to the new
backlight driver.

Regards,
Colin


Follow ups

References