Laptop screen blank on resume with kernel 5.13.x
 

On my RX580-based laptop running 5.13.x, closing the lid and reopening it results in a blank screen. There are no errors in any logs. Issue fixed by reverting the following commit:

commit 9127daa0a8d88a6e6452eb8b7c9be4c3f42a867e
Author: Stylon Wang <stylon.wang@amd.com>
Date: Tue Mar 2 19:25:56 2021 +0800

drm/amd/display: Guard ASSR with internal display flag

[Why]
ASSR enabling only considers capability declared in DPCD.
We also need to check whether the connector is internal.

[How]
ASSR enabling need to check both DPCD capability and internal display
flag.

Signed-off-by: Stylon Wang <stylon.wang@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

The AMD folks are working on a patch. More info here: https://bugzilla.kernel.org/show_bug.cgi?id=213779

5.13.9 resolves this issue.