drm/amd/display: Update link rate from DPCD 10
authorWesley Chalmers <Wesley.Chalmers@amd.com>
Thu, 16 May 2019 16:40:25 +0000 (12:40 -0400)
committerAlex Deucher <alexander.deucher@amd.com>
Tue, 11 Jun 2019 17:49:08 +0000 (12:49 -0500)
commit53c81fc7875bc2dca358485dac3999e14ec91a00
tree16162de453994c0a9c9413d944be99ffac21f27b
parent540c122924bd260c5124534d16bd75c0b62f5856
drm/amd/display: Update link rate from DPCD 10

[WHY]
Some panels return a link rate of 0 (unknown) in DPCD 0. In this case,
an appropriate mode cannot be set, and certain panels will show
corruption as they are forced to use a mode they do not support.

[HOW]
Read DPCD 10 in the case where supported link rate from DPCD 0 is
unknown, and pass that value on to the reported link rate.
This re-introduces behaviour present in previous versions that appears
to have been accidentally removed.

Signed-off-by: Wesley Chalmers <Wesley.Chalmers@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c