drm/i915: Refresh that status of MST capable connectors in ->detect()

commit fc22b787 upstream.

Once we've determined that the sink is MST capable we never end up
running through the full detect cycle again, despite getting HPDs.
Fix tht by ripping out the incorrect piece of code responsible.

This got broken when I moved the long HPD handling to the ->detect()
hook, but failed to remove the leftover code.

Cc: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Cc: Rui Tiago Matos <tiagomatos@gmail.com>
Tested-by: Rui Tiago Matos <tiagomatos@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98323
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Tested-by: Kirill A. Shutemov <kirill@shutemov.name>
References: https://bugs.freedesktop.org/show_bug.cgi?id=98306
Fixes: 10158116 ("drm/i915: Move long hpd handling into the hotplug work")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1477057478-29328-1-git-send-email-ville.syrjala@linux.intel.comReviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
(cherry picked from commit 1aab956c)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/i915/intel_dp.c

@@ -4323,21 +4323,11 @@ static enum drm_connector_status
 intel_dp_detect(struct drm_connector *connector, bool force)
 {
 	struct intel_dp *intel_dp = intel_attached_dp(connector);
-	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
-	struct intel_encoder *intel_encoder = &intel_dig_port->base;
 	enum drm_connector_status status = connector->status;
 
 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
 		      connector->base.id, connector->name);
 
-	if (intel_dp->is_mst) {
-		/* MST devices are disconnected from a monitor POV */
-		intel_dp_unset_edid(intel_dp);
-		if (intel_encoder->type != INTEL_OUTPUT_EDP)
-			intel_encoder->type = INTEL_OUTPUT_DP;
-		return connector_status_disconnected;
-	}
-
 	/* If full detect is not performed yet, do a full detect */
 	if (!intel_dp->detect_done)
 		status = intel_dp_long_pulse(intel_dp->attached_connector);