[PATCH 25/32] drm/amd/display: Use HBR2 if eDP monitor it doesn't advertise link rate

[Alex Deucher]

From: Harry Wentland <harry.wentland at amd.com>

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 at amd.com>
Acked-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index a6dcd4246c20..7f0fdf73d499 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -2396,6 +2396,10 @@ bool detect_dp_sink_caps(struct dc_link *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;
 }
 
-- 
2.13.6