On Thu, 06 Nov 2014, Arnd Hannemann <arnd@xxxxxxxxxx> wrote: > Hi, > > I have a Thinkpad T440s (Haswell) connected to two additional Monitors > via a Docking Station (MST). > > During Bootup all three displays work, even when X is started. > However, if the laptop display is turned off once (either because of > power saving, or via xrandr), it fails to "come back". > That is if I try to re-enable it the Display stays blank. > I believe this used to work in 3.17. > > Here is the xrandr Ouput of the edp, when its enabled (but staying blank): > Screen 0: minimum 8 x 8, current 3840 x 1200, maximum 32767 x 32767 > eDP1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 309mm x 175mm > 1920x1080 60.0*+ 59.9 > > here is the debug output, while trying to enable it: > ... > [ 416.538848] [drm:intel_edp_backlight_power] panel power control backlight disable > > > I'm happy to provide further input. What does cat /sys/class/backlight/intel_backlight/bl_power say? What if you echo 0 there? BR, Jani. -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
