drm/i915/hdcp: Check if media_gt exists

Check if media_gt exists if we are using gsc cs

--v2
-correct typo [Ankit]
-assign gsc variable if gt exists [Ankit]

--v3
-declare gsc and gt variables in if block [Ankit]

--v4
-add fixes tag [Ankit]

Fixes: 8836317 ("drm/i915/mtl: Add HDCP GSC interface")
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230505041512.585486-1-suraj.kandpal@intel.com
(cherry picked from commit 6986f05)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Author: surajk8

drivers/gpu/drm/i915/display/intel_hdcp.c

@@ -204,18 +204,20 @@ bool intel_hdcp2_capable(struct intel_connector *connector)
 	struct intel_digital_port *dig_port = intel_attached_dig_port(connector);
 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
 	struct intel_hdcp *hdcp = &connector->hdcp;
-	struct intel_gt *gt = dev_priv->media_gt;
-	struct intel_gsc_uc *gsc = &gt->uc.gsc;
 	bool capable = false;
 
 	/* I915 support for HDCP2.2 */
 	if (!hdcp->hdcp2_supported)
 		return false;
 
 	/* If MTL+ make sure gsc is loaded and proxy is setup */
-	if (intel_hdcp_gsc_cs_required(dev_priv))
-		if (!intel_uc_fw_is_running(&gsc->fw))
+	if (intel_hdcp_gsc_cs_required(dev_priv)) {
+		struct intel_gt *gt = dev_priv->media_gt;
+		struct intel_gsc_uc *gsc = gt ? &gt->uc.gsc : NULL;
+
+		if (!gsc || !intel_uc_fw_is_running(&gsc->fw))
 			return false;
+	}
 
 	/* MEI/GSC interface is solid depending on which is used */
 	mutex_lock(&dev_priv->display.hdcp.comp_mutex);