drm/amd/display: Improve DisplayPort monitor interop
authorAric Cyr <aric.cyr@amd.com>
Tue, 26 May 2020 17:56:53 +0000 (13:56 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 19 Aug 2020 06:26:18 +0000 (08:26 +0200)
commit1adb2ff1f6b170cdbc3925a359c8f39d2215dc20
treed4a0a8f8d69b9079f91f5a2276522e9af21733b7
parent1839d11b9bb2c5b5ec388722176d08a7e4c65600
drm/amd/display: Improve DisplayPort monitor interop

[ Upstream commit eec3303de3378cdfaa0bb86f43546dbbd88f94e2 ]

[Why]
DC is very fast at link training and stream enablement
which causes issues such as blackscreens for non-compliant
monitors.

[How]
After debugging with scaler vendors we implement the
minimum delays at the necessary locations to ensure
the monitor does not hang.  Delays are generic due to
lack of IEEE OUI information on the failing displays.

Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Acked-by: Tony Cheng <Tony.Cheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/gpu/drm/amd/display/dc/core/dc_link.c
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c