From 2d4baa4891c0193dbac1d963f231025f6bd8bcf7 Mon Sep 17 00:00:00 2001
From: Wenjing Liu <wenjing.liu@amd.com>
Date: Fri, 13 Aug 2021 19:49:43 -0400
Subject: drm/amd/display: update conditions to do dfp cap ext validation
Git-commit: 928adbf65bb1f813487164edde6293bf42d8f195
Patch-mainline: v5.16-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
[why]
According to DP specs dfp cap ext validation is only for branch
device withou 128b/132b channel coding support and
downstream of the branch device doesn't have compression.
Therefore we are adding conditions to only do dfp cap
extension validation for branch devcie supporting 8b/10b
channel coding only and it has no DSC passthrough capability.
Acked-by: Mikita Lipski <mikita.lipski@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Reviewed-by: George Shen <george.shen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/dc/core/dc_link.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
index 74e18275de3d..c5a564b5541d 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -2606,7 +2606,9 @@ static bool dp_active_dongle_validate_timing(
#if defined(CONFIG_DRM_AMD_DC_DCN)
}
- if (dongle_caps->dfp_cap_ext.supported) {
+ if (dpcd_caps->channel_coding_cap.bits.DP_128b_132b_SUPPORTED == 0 &&
+ dpcd_caps->dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_PASSTHROUGH_SUPPORT == 0 &&
+ dongle_caps->dfp_cap_ext.supported) {
if (dongle_caps->dfp_cap_ext.max_pixel_rate_in_mps < (timing->pix_clk_100hz / 10000))
return false;
--
2.38.1