[Intel-gfx] [PATCH] drm/i915: Flush the workqueue before draining

[Chris Wilson]

Trying to drain a workqueue while we may still be adding to it from
background tasks is, according to kernel/workqueue.c, verboten. So, add
a flush_workqueue() at the start of our cleanup procedure.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_drv.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 09e09d26e67d..979a30764e91 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2473,6 +2473,7 @@ static inline void i915_gem_drain_workqueue(struct drm_i915_private *i915)
 	 */
 	int pass = 3;
 	do {
+		flush_workqueue(i915->wq);
 		rcu_barrier();
 		i915_gem_drain_freed_objects(i915);
 	} while (--pass);
-- 
2.20.1