Black screen after screen lock

Question

Some time ago, I tried to install tensorflow-gpu on my Linux Mint 18.2 Sonya and probably broke something while doing so. I ended up with a black screen when booting. To fix this, I edited /etc/default/grub: GRUB_CMDLINE_LINUX="i915.modeset=0".

I'm using the i915 parameter because I have an intel motherboard (I believe).

Now I have a blackscreen after waking up my computer. Many of the solutions I found online required to change the GRUB_CMDLINE_LINUX parameter, but since I already had to edit this I don't think it's about changing the i915 parameter.

Do you know how to fix this problem ? Thank you !

EDIT: If I remove i915.modeset=0, I boot to a black screen. That's why I added this parameter in the first place, but it only fixes the black screen on boot issue. After making sure that Ctrl+Alt+Backspace is actually activated and logs me out, I tried to use it when "blackscreen-ed", and it won't fix the problem either. Thanks to @terdon for suggesting theses fixes though!

Answer 1

I have a similar problem and I've had it with a variety of machines and systems. I have never been able to track down the root cause of it, but as a workaround, I have assigned a keyboard shortcut to an xrandr command that sets up my screens. That might be worth a try here.

1. Figure out your current screen setup by looking at the output of xrandr:

   $ xrandr
   Screen 0: minimum 320 x 200, current 6400 x 1440, maximum 8192 x 8192
   eDP-1 connected 2560x1440+3840+0 (normal left inverted right x axis y axis) 310mm x 174mm
      2560x1440     60.00*+  59.99    59.99    59.96    59.95  
      1920x1440     60.00  
      1856x1392     60.01  
      1792x1344     60.01  
      2048x1152     59.99    59.98    59.90    59.91  
      1920x1200     59.88    59.95  
      1920x1080     60.01    59.97    59.96    59.93  
      1600x1200     60.00  
      1680x1050     59.95    59.88  
      1400x1050     59.98  
      1600x900      59.99    59.94    59.95    59.82  
      1280x1024     60.02  
      1400x900      59.96    59.88  
      1280x960      60.00  
      1440x810      60.00    59.97  
      1368x768      59.88    59.85  
      1280x800      59.99    59.97    59.81    59.91  
      1280x720      60.00    59.99    59.86    59.74  
      1024x768      60.04    60.00  
      960x720       60.00  
      928x696       60.05  
      896x672       60.01  
      1024x576      59.95    59.96    59.90    59.82  
      960x600       59.93    60.00  
      960x540       59.96    59.99    59.63    59.82  
      800x600       60.00    60.32    56.25  
      840x525       60.01    59.88  
      864x486       59.92    59.57  
      700x525       59.98  
      800x450       59.95    59.82  
      640x512       60.02  
      700x450       59.96    59.88  
      640x480       60.00    59.94  
      720x405       59.51    58.99  
      684x384       59.88    59.85  
      640x400       59.88    59.98  
      640x360       59.86    59.83    59.84    59.32  
      512x384       60.00  
      512x288       60.00    59.92  
      480x270       59.63    59.82  
      400x300       60.32    56.34  
      432x243       59.92    59.57  
      320x240       60.05  
      360x202       59.51    59.13  
      320x180       59.84    59.32  
   DP-1 disconnected (normal left inverted right x axis y axis)
   HDMI-1 disconnected (normal left inverted right x axis y axis)
   DP-2 disconnected (normal left inverted right x axis y axis)
   HDMI-2 disconnected (normal left inverted right x axis y axis)
   DP-3 disconnected (normal left inverted right x axis y axis)
   HDMI-3 disconnected (normal left inverted right x axis y axis)
   DP-3-1 disconnected (normal left inverted right x axis y axis)
   DP-3-2 connected primary 1920x1080+1920+0 (normal left inverted right x axis y axis) 531mm x 299mm
      1920x1080     60.00*+  60.00    50.00    59.94  
      1680x1050     59.88  
      1600x900      60.00  
      1280x1024     75.02    60.02  
      1440x900      59.90  
      1280x800      59.91  
      1152x864      75.00  
      1280x720      60.00    60.00    50.00    50.00    59.94  
      1024x768      75.03    70.07    60.00  
      832x624       74.55  
      800x600       72.19    75.00    60.32    56.25  
      720x576       50.00    50.00  
      720x480       60.00    60.00    59.94    59.94  
      640x480       75.00    72.81    66.67    60.00    59.94  
      720x400       70.08  
   DP-3-3 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 477mm x 268mm
      1920x1080     60.00*+
      1680x1050     59.95  
      1280x1024     75.02    60.02  
      1152x864      75.00  
      1024x768      75.03    60.00  
      800x600       75.00    60.32  
      640x480       75.00    59.94  
      720x400       70.08  
   

   I actually have 3 screens active, so my output is a bit complex. This is what it would look like for a single screen setup:

   $ xrandr
   Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 8192 x 8192
   eDP-1 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 310mm x 174mm
      2560x1440     60.00*+  59.99    59.99    59.96    59.95  
      1920x1440     60.00  
      1856x1392     60.01  
      1792x1344     60.01  
      2048x1152     59.99    59.98    59.90    59.91  
      1920x1200     59.88    59.95  
      1920x1080     60.01    59.97    59.96    59.93  
      1600x1200     60.00  
      1680x1050     59.95    59.88  
      1400x1050     59.98  
      1600x900      59.99    59.94    59.95    59.82  
      1280x1024     60.02  
      1400x900      59.96    59.88  
      1280x960      60.00  
      1440x810      60.00    59.97  
      1368x768      59.88    59.85  
      1280x800      59.99    59.97    59.81    59.91  
      1280x720      60.00    59.99    59.86    59.74  
      1024x768      60.04    60.00  
      960x720       60.00  
      928x696       60.05  
      896x672       60.01  
      1024x576      59.95    59.96    59.90    59.82  
      960x600       59.93    60.00  
      960x540       59.96    59.99    59.63    59.82  
      800x600       60.00    60.32    56.25  
      840x525       60.01    59.88  
      864x486       59.92    59.57  
      700x525       59.98  
      800x450       59.95    59.82  
      640x512       60.02  
      700x450       59.96    59.88  
      640x480       60.00    59.94  
      720x405       59.51    58.99  
      684x384       59.88    59.85  
      640x400       59.88    59.98  
      640x360       59.86    59.83    59.84    59.32  
      512x384       60.00  
      512x288       60.00    59.92  
      480x270       59.63    59.82  
      400x300       60.32    56.34  
      432x243       59.92    59.57  
      320x240       60.05  
      360x202       59.51    59.13  
      320x180       59.84    59.32  
   DP-1 disconnected (normal left inverted right x axis y axis)
   HDMI-1 disconnected (normal left inverted right x axis y axis)
   DP-2 disconnected (normal left inverted right x axis y axis)
   HDMI-2 disconnected (normal left inverted right x axis y axis)
   DP-3 disconnected (normal left inverted right x axis y axis)
   HDMI-3 disconnected (normal left inverted right x axis y axis)
   DP-3-1 disconnected (normal left inverted right x axis y axis)
   DP-3-2 disconnected (normal left inverted right x axis y axis)
   DP-3-3 disconnected (normal left inverted right x axis y axis)
   

   Based on the output you get from xrandr, you can build a command that would duplicate your current setup. So, to get my three screens, I would use:

   xrandr --output eDP-1 --mode 2560x1440 --output DP-3-2 --auto --left-of eDP-1 --primary --output DP-3-3 --left-of DP-3-2 --auto 
   

   For a single screen, it would be:

   xrandr --output eDP-1 --mode 2560x1440  --primary
   

   Or even just:

   xrandr --output eDP-1 --auto
   

   That will set up my laptop's screen (eDP-1) at the far right, and my other two screens to the left of it. Play around with xrandr and get the command that works for you. Note that the screen names will be different on your system and you will need to work out which is which.

2. Once you have the right xrandr command, set a desktop shortcut for it. For example, on Cinnamon, I can do this by going to Preferences => Keyboard => Shortcuts => Custom shortcuts:

   

As you can see in the image, I have assigned the shortcut Super+3 ("Super" is the "Windows key"). So if my laptop's screen fails to wake up after suspending, I just hit the shortcut and that refreshes the screen, effectively waking it up.