01:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI Thames [Radeon 7550M/7570M/7650M] $ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 13.04 Release: 13.04 Codename: raring Linux ebi 3.8.0-21-generic #32-Ubuntu SMP Tue May 14 22:16:46 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux This is a HP elitebook 8470w I'm happy to provide further infos if someone tells what's needed
If the OEM used the integrated backlight controller in the GPU it should be exposed via sysfs (there should be a radeon entry in /sys/class/backlight). You can use that interface to control the backlight.
Weird, the xubuntu 13.04 livecd can control brightness but the installed system not... investigating further
Adam Groszer, Ubuntu 13.04 reached EOL on January 27, 2014. For more on this, please see https://wiki.ubuntu.com/Releases . If this is reproducible, it will help immensely if you filed a new report with Ubuntu by ensuring you have the package xdiagnose installed, and that you click the Yes button for attaching additional debugging information running the following from a terminal: ubuntu-bug xorg Also, please feel free to subscribe me to it. For more on why this is helpful, please see https://wiki.ubuntu.com/ReportingBugs.
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