I am using a lenovo thinkpad w520 running fedora 22 and gnome 3. This particular laptop has both an integrated (Intel HD Graphics 3000) and discrete graphics (NVIDIA Quadro 1000M) card. When I'm in Linux, I only ever use the integrated graphics card because support for the NVIDIA card isn't awesome without installing proprietary drivers.
For the most part, this works well, except that the screen is always on 100% brightness. Turning down the brightness with either the keyboard controls or in the Gnome pane has no effect.
I did some poking and discovered that in the
/sys/class/backlight directory there are two entries:
nv_backlight. I tried changing the brightness in the Gnome pane and watched the
nv_backlight/brightness files. The former does not change but the latter does. If I manually change the former, the true brightness actually does update.
So I guess I need to figure out how to tell gnome to use the
intel_backlight device rather than the
nv_backlight device. How would I go about doing this?