Description of problem: Backlight is off and not changeable. Version-Release number of selected component (if applicable): Fedora 20 Alpha (Updates until 2013-011-08), kernel-3.11.7-300.fc20 How reproducible: everytime Steps to Reproduce: 1. install Fedora 20 Alpha (plugin external monitor and switch the monitor output with (FN + F1) to clone the display to external monitor (because the laptop-display is corrupted) 2. make updates until 2013-011-08 (kernel-3.11.7-300.fc20 or later should be installed) 3. reboot: -> the display should work without corruption, but backlight is off 2. try to control brightness of the backlight Actual results: backlight remains dark Expected results: backlight change the level of brightness Additional info: Dell XPS 13, L322X (Sputnik, FullHD), Ubuntu 13.04 and Ubuntu 13.10 had the same problems, search the web for more bug reports
the following commands are without success: xbacklight echo -n 0 > /sys/module/video/parameters/brightness_switch_enabled /sys/class/backlight/intel_backlight/brightness /sys/class/backlight/acpi_video0/brightness
The slider of the gnome brightness control is very choppy. So maybe it tries to set something, that require some time.
I have the same problem, with the same laptop I think #903136 is related, looks like 3.12 fix the problems
Hi, I've been researching backlight issues for the last few days and I think I'm starting to get a handle on them, or at least to some degree. Can you install with the latest fedora kernel: http://koji.fedoraproject.org/koji/buildinfo?buildID=513888 (download the rpm for your arch, and install it with "rpm -ivh kernel...rpm") ? And boot it with "video.use_native_backlight=1" on the kernel cmdline (press esc at the grub screen to stop grub from booting, then e to edit the entry for the latest kernel, then go the line starting with linux, and add the end of that line add a space and then ideo.use_native_backlight=1), then press F10 to boot. Once booted check if the brightness control now works properly, also please run the following 2 commands: grep '.*' /sys/class/dmi/id/*_* 2> /dev/null ls /sys/class/backlight And copy and paste the output here. Thanks, Hans
Hi, I've just learned that this should be fixed in 3.15-rc3 and later, see: https://bugs.freedesktop.org/show_bug.cgi?id=76276 Can you please try installing this kernel: http://koji.fedoraproject.org/koji/buildinfo?buildID=513881 And see if that fixes things ? Thanks, Hans
So as mentioned in comment 5, I'm pretty sure that this is: https://bugs.freedesktop.org/show_bug.cgi?id=76276 Which has a patch attached for 3.14 stable too, perhaps we should at that patch to the Fedora kernels until it trickles down through stable ?
I don't have access to this Dell Laptop at this time. This Laptop is owned by a friend and he removed Ubuntu and Fedora and only Win 8 is installed :-( So a new Fedora install is at the moment impossable. With a live system (USB stick) it seems not possible to try this? I had to boot a live system, install the patch and then I must reboot. But the reboot is impossable with a live system :-(
Hi Rolle, (In reply to Rolle from comment #7) > I don't have access to this Dell Laptop at this time. This Laptop is owned > by a friend and he removed Ubuntu and Fedora and only Win 8 is installed :-( > So a new Fedora install is at the moment impossable. > With a live system (USB stick) it seems not possible to try this? I had to > boot a live system, install the patch and then I must reboot. But the reboot > is impossable with a live system :-( No problem, there was a known bug with XPS machines backlight which has been fixed upstream and in the Fedora kernels for a while now. I'm pretty sure that this is fixed now, so lets just close this bug. Thanks for your support / help with solving this! Regards, Hans