[i915] eDP cannot light up after waking up from suspend the second time.

Submitted by Yvonne

Assigned to Intel GFX Bugs mailing list

Link to original bug (#112407)

Description

Created attachment 146033
dmesg log

Platform: CML Laptop with ALC711+ ALC1308+ ALC715 in SDW mode

Reproduce Steps:

1.Do system reboot with HDMI/DP external port connected.
2.Enter suspend via "sudo rtcwake -m mem -s 10", and unplug HDMI/DP external port during suspend.
3.Enter suspend again after waking up from suspend in step2

Frequency:100%

Expected result:
After step3, eDP should light up after waking up from suspend.

Actual result:
After step3, eDP cannot light up after waking up from suspend.

Tested it with linux-image-unsigned-5.4.0-050400-generic_5.4.0-050400.201911242031_amd64.deb, issue can still be reproduced.

With HDA legacy driver, same symptom still exist.

Need to fix in graphics driver.

Attachment 146033, "dmesg log":
i915_dmesg.log