[Intel-gfx] [PATCH v2 9/9] drm/i915: Allow per-lane drive settings with LTTPRs

Ville Syrjala ville.syrjala at linux.intel.com
Wed Sep 29 16:55:25 UTC 2021


From: Ville Syrjälä <ville.syrjala at linux.intel.com>

LTTPRs should support per-lane drive settings I think, and even if
they don't they should implement their own fallback logic to determine
suitable common drive settings to use for all the lanes.

v2: Actually check the correct thing

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp_link_training.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
index f26c44a6b568..eeea6c73e218 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
@@ -304,7 +304,7 @@ static u8 intel_dp_phy_preemph_max(struct intel_dp *intel_dp,
 static bool has_per_lane_signal_levels(struct intel_dp *intel_dp,
 				       enum drm_dp_phy dp_phy)
 {
-	return false;
+	return !intel_dp_phy_is_downstream_of_source(intel_dp, dp_phy);
 }
 
 static u8 intel_dp_get_lane_adjust_train(struct intel_dp *intel_dp,
-- 
2.32.0



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