I tested on an L322X with _F_HD display and A09 BIOS in UEFI mode. $ cat /proc/cmdline BOOT_IMAGE=/vmlinuz-3.11.0-14-generic root=/dev/mapper/ubuntu--vg-root ro splash quiet i915.disable_pch_pwm=0 vt.handoff=7
If I use i915.disable_pch_pwm=0 with the legacy OPROM enabled, I have to run "echo 0 > /sys/class/backlight/intel_backlight/brightness", after which the backlight keys work. If I use i915.disable_pch_pwm=1 with the legacy OPROM _disabled_, the backlight keys work without any additional work. If I use i915.disable_pch_pwm=0 with the legacy OPROM _disabled_, your test kernel fixes the backlight issue. (However, apparently Saucy's kernel causes really bad graphics corruption if the legacy OPROM is disabled, which is a separate issue.) And for kicks, i915.disable_pch_pwm=1 with the legacy OPROM disabled brings the system up with the backlight at its lowest setting. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1163720 Title: Brightness control broken on XPS13 and 3.8.0-16, 3.8.0-22 and 3.11.0-12 To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1163720/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
