GNOME Settings Daemon

Bug #527157
Comment #22

Comment 22 for bug 527157

Revision history for this message

Mark Smith (tntc-tig) wrote on 2012-02-24:

#22

Happy Birthday Bug 527157! Gee, has it been two years already? It feels like just yesterday I was wondering why I couldn't get more than 5-7 brightness levels! Three Ubuntu releases later, and I've had to find two different solutions to the same problem. Maybe it's a g-p-m bug! Maybe it's a kernel bug! I've heard claims that the kernel is reporting xrandr brightness change failures even though the change actually succeeded. Who knows?!

For those of you who are tired of patching Gnome-Power-Manager, or trying unsuccesfully to patch the new version in the Gnome 3 branches, I may have found a solution less likely to get clobbered by system updates. The fix worked for this bug on my next laptop, an Alienware M11x r2. I've since moved on to OS X on a Macbook Air, but my hope is that it will help other poor souls just trying to get a comfortable brightness level.

Add the following options to your kernel boot parameters:
acpi_backlight=vendor

I can't guarantee this will work on your laptop. It gave me 15 brightness levels on the Alienware (instead of the default 9 in windows or 4.5 in unmodified ubuntu). An unpleasant side effect was that the screen would go to sleep and not wake up, even though the system was still accessible via ssh. No amount of hand waving or xrandr prodding managed to fix this, or revive the comatose screen. I "solved" this by setting my display to never turn off unless I closed the screen.

Despite my snark, I am appreciative of the work put in by people to fix this bug. I would like to thank everyone who helped out on this bug with your comments and testing.

I would like to give special thanks to Darwin Bautista and Konstantin Lavrov for working so diligently on the original patch. Your work let me use my machine with the proper brightness levels right up until the 3.x tree of GPM. Without you guys (and especially Darwin's ppa), I would've never had proper screen brightness, and would've never known where to look when resolving this issue in the next version of GPM.

From the bottom of my heart, thank you all.

Happy Birthday Bug 527157!  Gee, has it been two years  already? It feels like just yesterday I was wondering why I couldn't get more than 5-7 brightness levels! Three Ubuntu releases later, and I've had to find two different solutions to the same problem. Maybe it's a g-p-m bug! Maybe it's a kernel bug! I've heard claims that the kernel is reporting xrandr brightness change failures even though the change actually succeeded.  Who knows?!

For those of you who are tired of patching Gnome-Power-Manager, or trying unsuccesfully to patch the new version in the Gnome 3 branches, I may have found a solution less likely to get clobbered by system updates. The fix worked for this bug on my next laptop, an Alienware M11x r2.  I've since moved on to OS X on a Macbook Air, but my hope is that it will help other poor souls just trying to get a comfortable brightness level.

Add the following options to your kernel boot parameters:
acpi_backlight=vendor

I can't guarantee this will work on your laptop. It gave me 15 brightness levels on the Alienware (instead of the default 9 in windows or 4.5 in unmodified ubuntu). An unpleasant side effect was that the screen would go to sleep and not wake up, even though the system was still accessible via ssh. No amount of hand waving or xrandr prodding managed to fix this, or revive the comatose screen.  I "solved" this by setting my display to never turn off unless I closed the screen.

Despite my snark, I am appreciative of the work put in by people to fix this bug. I would like to thank everyone who helped out on this bug with your comments and testing.

From the bottom of my heart, thank you all.