drm/amd/display: wait for pending complete when enabling a plane
authorJun Lei <Jun.Lei@amd.com>
Tue, 16 Jul 2019 17:02:41 +0000 (13:02 -0400)
committerAlex Deucher <alexander.deucher@amd.com>
Thu, 15 Aug 2019 15:54:02 +0000 (10:54 -0500)
commit986936d1a9b29bd40be2acdf91d9e99ecda3bf33
treee22626fd7e4766d7c5478a349f5c2958a53d0b67
parent91db9311945f01901ddb9813ce11364de214a156
drm/amd/display: wait for pending complete when enabling a plane

[why]
When planes are enabled, they must be enabled using VSYNC update (not immediate).
However, before the VUPDATE occurs, DM may call with an "immediate" flip which is address
only.  This operation would normally be okay, but if the locking for immediate flip happens
to occur before the VUPDATE associated with the initial plane enablement, it will cause HW
to hang.

[how]
HWSS should enforce plane enable in HW to be synchronous with the call that enables the plane.

Signed-off-by: Jun Lei <Jun.Lei@amd.com>
Reviewed-by: Eric Yang <eric.yang2@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c