Brightness control problems

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qlum
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Joined: Tue Apr 17, 2012 10:15 am

Brightness control problems

Post by qlum »

First of all the issues started after I went from the open source drivers to the catalyst drivers before that it worked perfectly and I am using a lenovo x121e with a e350 apu.

Now when I turn up and down the brightness usually nothing happens but sometimes it does respond however when I go to standby after changing it the brightness has changed when I get back out of standby. While this is workable it is far from ideal especially when you are watching video and want to adjust the brightness along the way.

Any solutions for this problem?

I already tried all that is in this guide or at least the applicable stuff: http://forums.linuxmint.com/viewtopic.php?f=42&t=45271
and the first thing made my brightness control completely non functional, the second thing neither improved nor regressed from my current situation.
qlum
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Joined: Tue Apr 17, 2012 10:15 am

Re: Brightness control problems

Post by qlum »

anyone?
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roblm
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Re: Brightness control problems

Post by roblm »

Can't you control the brightness level through the Catalyst Control Center that is installed with the catalyst driver?

You can try making these changes to the grub file. In the Terminal type: gksudo gedit /etc/default/grub.
Change the line: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
to one of the lines below:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash thinkpad-acpi.brightness_enable=1 acpi_backlight=vendor”
GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_osi=Linux”
GRUB_CMDLINE_LINUX_DEFAULT="acpi_osi="
GRUB_CMDLINE_LINUX_DEFAULT="quite splash acpi_osi=Linux acpi_backlight=vendor"

In the Terminal type: sudo update-grub. Reboot.

Sometimes making changes to the grub file can cause startup problems. If this happens then restart and select the correct operating system at the Grub Boot Menu and then press e. Go down to the line that starts with:
linux /boot/vmlinuz.......................ro quiet splash $vt_handoff
Remove the command you added between the word “splash” and “$vt”.
Press Ctrl+x or F10. This change is just temporary and allows you to start your system. Then remove the command in the /etc/default/grub file.
If you have only one operating system installed, then a Grub Boot Menu may not be displayed. Hold down the Shift key while starting, or if this doesn't work, keep tapping the Shift key while starting.
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