drm/xe/hdcp: Check GSC structure validity

Sometimes xe_gsc is not initialized when checked at HDCP capability
check. Add gsc structure check to avoid null pointer error.
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Dnyaneshwar Bhadane <dnyaneshwar.bhadane@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240722064451.3610512-4-suraj.kandpal@intel.com

drivers/gpu/drm/xe/display/xe_hdcp_gsc.c

@@ -40,10 +40,14 @@ bool intel_hdcp_gsc_check_status(struct xe_device *xe)
 {
 	struct xe_tile *tile = xe_device_get_root_tile(xe);
 	struct xe_gt *gt = tile->media_gt;
+	struct xe_gsc *gsc = &gt->uc.gsc;
 	bool ret = true;
 
-	if (!xe_uc_fw_is_enabled(&gt->uc.gsc.fw))
+	if (!gsc && !xe_uc_fw_is_enabled(&gsc->fw)) {
+		drm_dbg_kms(&xe->drm,
+			    "GSC Components not ready for HDCP2.x\n");
 		return false;
+	}
 
 	xe_pm_runtime_get(xe);
 	if (xe_force_wake_get(gt_to_fw(gt), XE_FW_GSC)) {
@@ -53,7 +57,7 @@ bool intel_hdcp_gsc_check_status(struct xe_device *xe)
 		goto out;
 	}
 
-	if (!xe_gsc_proxy_init_done(&gt->uc.gsc))
+	if (!xe_gsc_proxy_init_done(gsc))
 		ret = false;
 
 	xe_force_wake_put(gt_to_fw(gt), XE_FW_GSC);