The same for me, xps13, full hd, booting from UEFI. Working well with previous kernel version (3.8.0-29-generic). After updating to the latest (3.8.0-30-generic) the problem is back again.
martin@flegy-nb:~$ uname -a Linux flegy-nb 3.8.0-30-generic #44-Ubuntu SMP Thu Aug 22 20:52:24 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux martin@flegy-nb:~$ cat /etc/issue Ubuntu 13.04 \n \l When I am trying to change backlight (f4/f5) I see changes in /sys/class/backlight/intel_backlight/actual_brightness but without any effect on the backlight -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1169376 Title: 8086:0166 [Dell XPS 13 L322X] backlight stopped working after update 3.8.0-18.28 To manage notifications about this bug go to: https://bugs.launchpad.net/dell-sputnik/+bug/1169376/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
