drm/i915/dp: Restrict link retrain workaround to external monitors

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@redhat.com>
Cc: Jan-Marek Glogowski <glogow@fbihome.de>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
References: 3cf71bc9904d ("drm/i915: Re-apply "Perform link quality check, unconditionally during long pulse"")
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180927205735.16651-2-dhinakaran.pandiyan@intel.com

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 207b3ea2ed1a2ab35d4c305f9cff9981e00e48c5..4e0870f3a4a5f62bc132a99160d714b4fe34f830 100644 (file)
--- 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);