Monitor does not wake from sleep with Haswell/DisplayPort

Submitted by Mark

Assigned to Intel GFX Bugs mailing list

Link to original bug (#111690)

Description

Reproduction:

1. Start X-Windows with "startx".
   
2. Allow computer to idle until it enters sleep mode, or put computer to sleep with "systemctl suspend"
   
3. Monitor displays "no signal" and goes to sleep after a few seconds
   
4. Press any key to wake up the computer
   
5. 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.