Home > e-infrastructure, Glitches&Errors, os, service-is-testing-troubleshooting-debugging > How to fix primary screen on Linux laptop not coming out of sleep

How to fix primary screen on Linux laptop not coming out of sleep

2014/10/17 Leave a comment Go to comments
  1. Problem: My Debian (Jessie) Linux laptop has issues with juggling a secondary screen and sleeping at the same time. More specifically, it seems:
    1. It seems if you come out of sleep with a secondary screen connected, even if you put the laptop to sleep with “it” (o.k., not the same “it”, just spec-wise the equivalent FULL HD LCD screen on VGA – being able to easily move the laptop to work in multiple places is kind of the point of having one in the first place), the primary laptop screen seems to remain asleep completely. FN keys to switch primary and secondary screen on laptop have no effect.
    2. If you disconnect the secondary screen, Linux does fall back onto the primary screen, however, “forgets” to turn the backlight on. FN keys to up brightness have no effect
    3.   have not found a reliable way avoiding the issue  – maybe always disconnecting secondary screen before putting laptop to sleep? If you don’t want to have to do this, or forget, try to use this:
  2. Workaround:
    1. While I could get to the tty shell on secondary screen using CTRL+ALT+F1, but using xrandr --auto gave can't open display.
    2. However, try installing this utility which I found recommended in a different context:
      1. aptitude search xbacklight
      2. xbacklight               - simple utility to set the backlight level
      3. aptitude install xbacklight
      4. Switch to a non-elevated user (or else you’ll get: No protocol specified" , "Primary laptop", "Can't open display :0", Why can't I run GUI apps from 'root': "No protocol specified"? : " In Debian $XAUTHORITY is usually not set explicitly.", "xauth list xauth:  file /root/.Xauthority does not exist" ).
      5. Then issue: xbacklight -set 50 OR issue xbacklight -inc 50.
      6. Viola: “Fiat lux”…
      7. Sleep takes out your primary screen and you are not good at blind starting, finding and typing into your Konsole? Right-click on the desktop of your secondary scree, “Run command”, and issue the same command line.
      8. Thank you, xbacklight.
Categories: e-infrastructure, Glitches&Errors, os, service-is-testing-troubleshooting-debugging Tags: , , , ,
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