[PATCH 3/9] drm/i915/dp: Restrict link retrain workaround to external monitors

[José Roberto de Souza]

From: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>

Commit '3cf71bc9904d ("drm/i915: Re-apply "Perform link quality check,
unconditionally during long pulse"")' applies a work around for sinks
that don't signal link loss. The work around does not need to have to be
that broad as the issue was seen with only one particular monitor; limit
this only for external displays as eDP features like PSR turn off the link
and the driver ends up retraining the link seeeing that link is not
synchronized.

Cc: Lyude Paul <lyude at redhat.com>
Cc: Jan-Marek Glogowski <glogow at fbihome.de>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
References: 3cf71bc9904d ("drm/i915: Re-apply "Perform link quality check, unconditionally during long pulse"")
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 34c561011e7a..6130d05d8b88 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -5072,12 +5072,13 @@ intel_dp_long_pulse(struct intel_connector *connector,
 		 */
 		status = connector_status_disconnected;
 		goto out;
-	} else {
-		/*
-		 * Some external monitors do not signal loss of link
-		 * synchronization with an IRQ_HPD, so force a link status
-		 * check.
-		 */
+	}
+
+	/*
+	 * Some external monitors do not signal loss of link synchronization
+	 * with an IRQ_HPD, so force a link status check.
+	 */
+	if (!intel_dp_is_edp(intel_dp)) {
 		struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
 
 		intel_dp_retrain_link(encoder, ctx);
-- 
2.19.0