Joined: 29 Feb 2004
Location: Coruña (Spain)
|Posted: Fri Jan 20, 2012 5:01 pm Post subject: [SOLVED] Backlight control on hp pavillion dv6 (sandy+ati)
|Has anyone managed to control the backlight on a recent hp pavillion dv6?
If I boot normally, I have two directories in /sys/class/backlight, called acpi_video0 and acpi_video1 (I assume one for the intel, one for the amd 6770m). However, echoing any value to acpi_videoX/backlight does nothing. The value is set, but the backlight doesn't change.
If I boot using "acpi_osi=Linux acpi_backlight=vendor", as suggested on the interwebz, I get an empty /sys/class/backlight. Some people talk about an "intel_backlight" directory appearing there (Ubuntu users mainly), but I haven't managed to get it. I don't see anything that suggests "intel backlight" in the kernel, so maybe it's an ubuntu patch.
(edit) Solved. I had to compile "Lowlevel Backlight controls" built-in, not as a module. That, together with "acpi_backlight=vendor" gives me the intel_backlight sys directory, from where I can change the backlight.