[PATCH] drm/i915/display: Fixed the main link lost in MST

[gareth.yu at intel.com]

From: Gareth Yu <gareth.yu at intel.com>

Re-train the main link for the main link lost in MST. The previous
version doesn't cover MST mode.

v5: Move link status check to the location which covers MST mode
v6: Correct Tejas' email address in cc

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10902
Cc: Tejas Upadhyay <tejas.upadhyay at intel.com>
Cc: Matt Roper <matthew.d.roper at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Gareth Yu <gareth.yu at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index e05e25cd4a94..8043740b4233 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5891,16 +5891,6 @@ intel_dp_detect(struct drm_connector *connector,
 
 	intel_dp_print_rates(intel_dp);
 
-	if (intel_dp->is_mst) {
-		/*
-		 * If we are in MST mode then this connector
-		 * won't appear connected or have anything
-		 * with EDID on it
-		 */
-		status = connector_status_disconnected;
-		goto out;
-	}
-
 	/*
 	 * Some external monitors do not signal loss of link synchronization
 	 * with an IRQ_HPD, so force a link status check.
@@ -5911,6 +5901,16 @@ intel_dp_detect(struct drm_connector *connector,
 			return ret;
 	}
 
+	if (intel_dp->is_mst) {
+		/*
+		 * If we are in MST mode then this connector
+		 * won't appear connected or have anything
+		 * with EDID on it
+		 */
+		status = connector_status_disconnected;
+		goto out;
+	}
+
 	/*
 	 * Clearing NACK and defer counts to get their exact values
 	 * while reading EDID which are required by Compliance tests
-- 
2.25.1