Using KScreen 2 I put the notebook to sleep while it's docked. When I resume it the two monitors attached to a docking station do not turn on. In KScreen KCM module they seems to be active and correctly configured. At this point if I change the configuration of one of the monitor in KScreen KCM it turns on after I press Apply, but I'm not able to turn them on together using this trick. So I need to undock and dock again the notebook. But since there is another bug, that makes KScreen forgot the configurations (I think it's already open) when the notebook is undocked I need to reconfigure KScreen again. So every time I put the notebook to sleep I need to: 1. Undock 2. Dock again 3. Reconfigure KScreen Reproducible: Always Steps to Reproduce: 1.Connect two monitors to a docking station Dell 2.Dock the notebook 3.Put to sleep 4.Resume Actual Results: External monitors not turning on Expected Results: External monitors turning on My configuration: Dell E7440 notebook connected to a docking station where two other monitors are connected
May be related: https://bugs.kde.org/show_bug.cgi?id=345227
KScreen relies on X server telling it that something has changed. Which with certain GPUs and drivers does not always happen when the change happens while the system is suspended or hibernated. Starting with KScreen 5.2 (from Plasma 5.2), KScreen force-checks new configuration after system is resumed, which should cause X server to figure out that there was a change and dispatch change notifications, which we can react to and toggle the screens respectively.
Thank you for the explanation.
Just tried with Plasma 5.2.2 and the problem persists. I've upgraded from KDE 4.
Isn't there a way to manually force KScreen to check for new configuration (as a workaround)? Because currently I need to undock and redock the notebook and all the windows are moved to on screen which is pretty annoying.
Problem still present in Plasma 5.4.2 in freshly installed Manjaro. Can I provide some extra information to try to solve this bug?
I can approve that the problem is exists in plasma 5.4.2 in archlinux. To force kscreen to apply its configuration you can just open kscreen kcm settings in systemsettings instead of re-plugging your external screens.
Doing it is problematic because systemsettings appears in the screen that is off. I solved this by using a shortcut to move the window to the active screen. But in my case opening kscreen does nothing, the two monitors remain off. I can reactivate them by doing this: 1. Disable both monitors 2. Apply settings 3. Enable both monitors 4. Apply settings Unfortunately when I apply settings in 2 and 4 the kscreen settings are lost (wrong position, wrong resolution), so that I need to reconfigure everything every time. See bugs: https://bugs.kde.org/show_bug.cgi?id=325277 https://bugs.kde.org/show_bug.cgi?id=346961
While I have not yet fully understood the full standby logic of kscreen. It seems to me that two things might change how the logic behaves: - The time it takes to suspend (kscreen uses a timer internally) - The state of the laptop lid Hence, does it make a difference to you if the lid is opened or closed?
I can suspend/resume via laptop lid/graphical interface/physical button and in any case the monitor doesn't wake up. Still present in Plasma 5.6. I cannot apply the workaround suggested above, because the problems in comment #8 are still present as well.
Another detail on this issue, is that sometimes there is no way to activate the monitor at all. In KScreen clicking enable and apply won't change anything. Often in this situation the list of resolutions available are wrong, so the monitor information are probably not detected at all, even though the monitor itself is detected as connected.
Also, I have this option related to the Intel driver in grub. Can this by related to the issues? GRUB_CMDLINE_LINUX=" acpi=force acpi_enforce_resources=lax i915.enable_rc6=1 i915.enable_fbc=1 i915.lvds_downclock=1 i915.semaphores=1"
I mark this as solved. In my case updating to Kernel 4.6 solved the problem. So it seems it was unrelated from KScreen.