drm/i915/gt: Warn CI about an unrecoverable wedge

If we have a wedged GPU that we need to recover, but fail, add a taint
for CI to pickup and schedule a reboot.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Petri Latvala <petri.latvala@intel.com>
Reviewed-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191002160034.5121-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_reset.c

@@ -872,8 +872,14 @@ static bool __intel_gt_unset_wedged(struct intel_gt *gt)
 	ok = !HAS_EXECLISTS(gt->i915); /* XXX better agnosticism desired */
 	if (!INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
 		ok = __intel_gt_reset(gt, ALL_ENGINES) == 0;
-	if (!ok)
+	if (!ok) {
+		/*
+		 * Warn CI about the unrecoverable wedged condition.
+		 * Time for a reboot.
+		 */
+		add_taint_for_CI(TAINT_WARN);
 		return false;
+	}
 
 	/*
 	 * Undo nop_submit_request. We prevent all new i915 requests from