Kamal, I booted with acpi_backlight=vendor, and that makes things worse out of the box. At max brightness (what it boots by default) no discernable difference. Then when the screen goes into idle after a few minutes not on AC it starts flickering at me violently. The same thing happens if I manually hit the brightness down keys. The lower the brightness the more aggressive the flicker until I go to zero brightness when the flicker goes away.
Also, it's worth noting, booting with that option created a dell_backlight in /sys/class/backlight as well as that intel_backlight. This is the same type of flicker that happens if I manually set any value (that I tried) in /sys/class/backlight/intel_backlight/brightness other than 0 or 4882. On Tue, Apr 10, 2012 at 16:33, Kamal Mostafa <ka...@canonical.com> wrote: > Mario, from your comment #5, it sounds to me like the problem may be due > to there being two /sys/class/backlight interfaces present (acpi_video0 > and intel_backlight). Mario & Daniel, you might try booting with the > kernel boot parameter "acpi_backlight=vendor" which should disable > acpi_video0 leaving only intel_backlight. Does that improve any of the > behaviors you're seeing (or make them worse)? > > -- > You received this bug notification because you are subscribed to the bug > report. > https://bugs.launchpad.net/bugs/954661 > > Title: > backlight brightness not adjustable by default on Dell XPS 13 > > To manage notifications about this bug go to: > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/954661/+subscriptions > -- Mario Limonciello supe...@gmail.com -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-intel in Ubuntu. https://bugs.launchpad.net/bugs/954661 Title: backlight brightness not adjustable by default on Dell XPS 13 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/954661/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp
