Monitors don't always wake up after sleep

Submitted by Michał Bartoszkiewicz

Assigned to Default DRI bug account

Link to original bug (#105188)

Description

Created attachment 137497
Kernel log

Hardware:
GPU: Gigabyte Radeon RX 480 G1 Gaming 8GB
Monitors: 3× Eizo FlexScan S2243W, connected using DP
Software:
Distribution: Gentoo
Kernel: 4.15.4
x11-drivers/xf86-video-amdgpu-1.4.0
x11-base/xorg-server-1.19.6
media-libs/mesa-18.0.0_rc4
x11-libs/libdrm-2.4.89

The monitors do not always correctly wake up from sleep.
E.g. after locking the session, the monitors go to sleep.
After pressing a key, only some wake up – the rest are still sleeping.
It does not seem to be deterministic – sometimes a monitor will wake up correctly, sometimes not.

The kernel log attached is after running the following script:
for i in {1..5}; do echo "XXX before suspend $i" | sudo tee /dev/kmsg; xset dpms force suspend; sleep 10; echo "XXX before on $i" | sudo tee /dev/kmsg; xset dpms force on; sleep 10; echo "XXX status $i:" $(cat /sys/devices/pci0000:00/0000:00:03.0/0000:03:00.0/drm/card0/card0-DP-*/status) | sudo tee /dev/kmsg; done

I am not sure if it is directly related to this issue, but the kernel log contains two refcount_t warnings in amdgpu code.

Attachment 137497, "Kernel log":
kernel-log.txt