From: Wenjing Liu <Wenjing.Liu@xxxxxxx>
[Description]
DP Compliance failure due to the max link cap is hard coded by feature
support.
Driver does not lower link cap based on receiver reported max link cap.
Signed-off-by: Wenjing Liu <Wenjing.Liu at amd.com>
Acked-by: Harry Wentland <harry.wentland at amd.com>
---
drivers/gpu/drm/amd/dal/dc/core/dc_link_dp.c | 30 +++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/amd/dal/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/dal/dc/core/dc_link_dp.c
index a2064acffcaa..c8de9af3a6c0 100644
--- a/drivers/gpu/drm/amd/dal/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/dal/dc/core/dc_link_dp.c
@@ -1076,17 +1076,31 @@ static bool exceeded_limit_link_setting(
true : false);
}
-static enum dc_link_rate get_max_link_rate(struct core_link *link)
+static struct dc_link_settings get_max_link_cap(struct core_link *link)
{
- enum dc_link_rate max_link_rate = LINK_RATE_HIGH;
+ /* Set Default link settings */
+ struct dc_link_settings max_link_cap = {LANE_COUNT_FOUR, LINK_RATE_HIGH,
+ LINK_SPREAD_05_DOWNSPREAD_30KHZ};
+ /* Higher link settings based on feature supported */
if (link->link_enc->features.flags.bits.IS_HBR2_CAPABLE)
- max_link_rate = LINK_RATE_HIGH2;
+ max_link_cap.link_rate = LINK_RATE_HIGH2;
if (link->link_enc->features.flags.bits.IS_HBR3_CAPABLE)
- max_link_rate = LINK_RATE_HIGH3;
-
- return max_link_rate;
+ max_link_cap.link_rate = LINK_RATE_HIGH3;
+
+ /* Lower link settings based on sink's link cap */
+ if (link->public.reported_link_cap.lane_count < max_link_cap.lane_count)
+ max_link_cap.lane_count =
+ link->public.reported_link_cap.lane_count;
+ if (link->public.reported_link_cap.link_rate < max_link_cap.link_rate)
+ max_link_cap.link_rate =
+ link->public.reported_link_cap.link_rate;
+ if (link->public.reported_link_cap.link_spread <
+ max_link_cap.link_spread)
+ max_link_cap.link_spread =
+ link->public.reported_link_cap.link_spread;
+ return max_link_cap;
}
bool dp_hbr_verify_link_cap(
@@ -1105,9 +1119,7 @@ bool dp_hbr_verify_link_cap(
success = false;
skip_link_training = false;
- max_link_cap.lane_count = LANE_COUNT_FOUR;
- max_link_cap.link_rate = get_max_link_rate(link);
- max_link_cap.link_spread = LINK_SPREAD_05_DOWNSPREAD_30KHZ;
+ max_link_cap = get_max_link_cap(link);
/* TODO implement override and monitor patch later */
--
2.10.1
