drm/amd/display: Mask DPCD field to avoid reading unsupported field value
authorJaehyun Chung <jaehyun.chung@amd.com>
Wed, 5 Aug 2020 21:28:53 +0000 (17:28 -0400)
committerAlex Deucher <alexander.deucher@amd.com>
Mon, 17 Aug 2020 18:09:06 +0000 (14:09 -0400)
commite0f7ff99c92ff5e033e169c30cff607ff7c17192
tree729e7cb863247456840ebf7acc24f4d1cbc2a52a
parent5ab7943187f22b572fd12d517bd699771b88ce91
drm/amd/display: Mask DPCD field to avoid reading unsupported field value

[Why]
DSC will be disabled if DPCD 0006F[6:3] is set to a non-zero value
because bits 6:3 are not currently supported. When 6:3 is populated, an
unsupported INCREMENT OF bits_per_pixel value is read (DPCD 0006F[2:0])

[How]
Mask the INCREMENT OF bits_per_pixel field so that values in the
unsupported field are ignored.

Signed-off-by: Jaehyun Chung <jaehyun.chung@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c