Added 20-intel.conf file with the same content, and now I'm able to log off / log in again.
Thanks!
]]>I have the same or a very similar issue with my Acer ES1-111 equipped with Intel HD Graphics (Bay Trail).
My system is running XFCE, LightDM, and Light Locker.
As far as I understand, this is what happens:
- The session is locked by Light Locker for any reason (E. g., being idle)
- To lock the session Light Locker switches to another vt (virtual terminal), starts X server on that vt and starts an instance of LightDM in that X server.
(As a side note, I'm not sure why Light Locker has to performs vt switching to lock a session but it is just the way Light Locker works -- take a look at the first comment on this issue https://bugs.launchpad.net/ubuntu/+sour … g/1336647)
- When the user unlocks the session Light Locker shuts down the X server it started (as described above).
- On the X server shutdown a bug in X server's intel video driver kicks in -- "Screen turned off after X server exits" (https://bugs.launchpad.net/ubuntu/+sour … ug/1501941 and https://bugs.freedesktop.org/show_bug.cgi?id=92457)
One workaround is to create
/etc/X11/xorg.conf.d/20-intel.conf
with the following content
Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "AccelMethod" "uxa"
EndSection
Take a look at https://wiki.archlinux.org/index.php/Intel_graphics for details.
Please notice, I actually had this file autogenrated for me and it contains many more sections and options than is shown above! So please be careful if you decide to just copy the above example as is.
But the key here is to set the "AccelMethod" option's value to "uxa" instead of "sna". The "sna" value is used by the driver by default (even if it is not explicitely set in the config).
This works very well for me. I don't have to press any shortcut to enable the screen when I unlock my session. I also haven't noticed any side effects from using the "uxa" acceleration method. Although admittedly it hasn't been a very long time since I switched to "uxa".
Another workaround may be adding Ubuntu's patch (see the link to Launchpad's bug 1336647 for details) to the deriver package, rebuilding it yourself, and installing it with pacman -U. But I did not try this myself.
Hope this helps.
]]>Edit: downgrading upower to 0.99.2-2 did not work for me.
]]>A temporary solution though, I hope the bug gets fixed soon (not sure if the source of the problem is light-dm, light-locker or upower, as said above).
]]>xset dpms force off
.
How? By setting a shortcut. If the backlight refuses to start, you just press the shortcut, type something (the password, for instance, in the case of screen locking) or move the mouse around and the light will be on again.
Not a perfect solution, but it works, at least in my case (a Dell Inspiron 3342).
]]>Lenovo Thinkpad with Arch Linux (Xfce and lightdm) here. Same behaviour after update last days. I downgraded upower package (to 0.99.2-2) which "cured" it. Package set to "hold" for the moment.
Ciao,
Photor
]]>I just ended up uninstalling lightdm and light-locker and using slock instead.
]]>This effect occurs whether I manually lock the screen, or if I allow the screen to turn off and lock, or even if I close the laptop lid and have it suspend.
This behavior didn't start until today. Before today, unlocking with LightDM brought me back to xfce.
Edit: The screen doesn't just turn blank. It seems to be turning off.
Edit2: I'm using light-locker. This may be the culprit.
]]>