From: Harry Wentland <harry.wentland@amd.com>
Date: Tue, 21 Nov 2017 13:34:48 -0500
Subject: drm/amd/display: Use HBR2 if eDP monitor it doesn't advertise link
 rate
Git-commit: 48231fd51667a89514d0eaba893ae0743fd0877d
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Some eDP displays use the extra link rate table to advertise link rate
support. If they do that they don't need to provide link rate through
the usual registers. Since we don't currently have support for the extra
link rate table default to HBR2 for the display in this.

Note that this is a HACK. Ultimately we need to teach DC to use the
extra link rate table.

Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -2393,6 +2393,10 @@ bool detect_dp_sink_caps(struct dc_link
 void detect_edp_sink_caps(struct dc_link *link)
 {
 	retrieve_link_cap(link);
+
+	if (link->reported_link_cap.link_rate == LINK_RATE_UNKNOWN)
+		link->reported_link_cap.link_rate = LINK_RATE_HIGH2;
+
 	link->verified_link_cap = link->reported_link_cap;
 }