drm/i915/gt: Flush retire.work timer object on unload

We need to wait until the timer object is marked as deactivated before
unloading, so follow up our gentle cancel_delayed_work() with the
synchronous variant to ensure it is flushed off a remote cpu before we
mark the memory as freed.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=111994Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191115150841.880349-1-chris@chris-wilson.co.uk

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

@@ -397,6 +397,7 @@ void intel_gt_driver_release(struct intel_gt *gt)
 void intel_gt_driver_late_release(struct intel_gt *gt)
 {
 	intel_uc_driver_late_release(&gt->uc);
+	intel_gt_fini_requests(gt);
 	intel_gt_fini_reset(gt);
 	intel_gt_fini_timelines(gt);
 }

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

@@ -130,3 +130,9 @@ void intel_gt_unpark_requests(struct intel_gt *gt)
 	schedule_delayed_work(&gt->requests.retire_work,
 			      round_jiffies_up_relative(HZ));
 }
+
+void intel_gt_fini_requests(struct intel_gt *gt)
+{
+	/* Wait until the work is marked as finished before unloading! */
+	cancel_delayed_work_sync(&gt->requests.retire_work);
+}

drivers/gpu/drm/i915/gt/intel_gt_requests.h

@@ -20,5 +20,6 @@ int intel_gt_wait_for_idle(struct intel_gt *gt, long timeout);
 void intel_gt_init_requests(struct intel_gt *gt);
 void intel_gt_park_requests(struct intel_gt *gt);
 void intel_gt_unpark_requests(struct intel_gt *gt);
+void intel_gt_fini_requests(struct intel_gt *gt);
 
 #endif /* INTEL_GT_REQUESTS_H */