I can confirm that https://bugzilla.kernel.org/attachment.cgi?id=97751 fixes the issue on the FHD version (also works after suspend and blank screen). I've attached the patch rebased on top of 3.8.0-26.38 in case somebody is eager to try it too.
** Patch added: "The patch for the FHD version from the kernel bugzilla, rebased on top of 3.8.0-26.38" https://bugs.launchpad.net/dell-sputnik/+bug/1169376/+attachment/3741292/+files/dell-xps13-fhd-backlight-fix.patch -- 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: XPS13 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 [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
