Monitor does not wake from sleep with Haswell/DisplayPort
Submitted by Mark
Assigned to Intel GFX Bugs mailing list
- Start X-Windows with "startx".
- Allow computer to idle until it enters sleep mode, or put computer to sleep with "systemctl suspend"
- Monitor displays "no signal" and goes to sleep after a few seconds
- Press any key to wake up the computer
- Computer wakes up, but monitor remains in sleep mode
My CPU is an i7-4770 and I'm using the integrated graphics.
My monitor is an Acer B276HUL.
I only observe the problem when connected with DisplayPort. DVI-D works fine. Those are the only two connectors available on my monitor. I have no other DisplayPort monitors to test.
Recovery from sleep works when running Linux 3-series kernels (latest tried was 3.16). I have other issues with those kernels so I would like to upgrade.
I've tried kernel versions 4.0-4.8 and 5.2 and they all exhibit this problem.
Switching to virtual terminal #1 (moved) (a non-X console display) usually wakes up the monitor. I can then switch back to my X terminal. Switching back to the terminal X sometimes causes X to crash, so this is not a good work around.
If I wake up the computer very shortly after it goes to sleep (before the monitor itself enters sleep mode), the display works fine.
If I manually wake up the monitor before waking up the computer by activating the monitor's on-screen settings display, then the display works correctly. Manually waking up the monitor after the computer wakes up is no good.