Can't change brightness on Toshiba l755 laptop

Posted by albert on Ask Ubuntu See other posts from Ask Ubuntu or by albert
Published on 2012-09-30T15:16:04Z Indexed on 2012/09/30 15:49 UTC
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12.04

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brightness

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toshiba

I have a Toshiba l755 laptop, and I installed 12.04 64bit on it. The default brightness of the laptop is set to maximum value, and I can't change it.

If I go to Configuration ? Brightness, the brightness doesn't change and neither does pressing the function keys.

I tried changing some parameters of grub file, setting GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor".

When changing the brightness from configuration, the value of /sys/class/backlight/toshiba/brightess changes, but screen remains the same. If I use the key functions, it changes the "actual_brightness" files. I don't know what else can I do, any suggestions?

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