[Intel-gfx] [PATCH] drm/i915: Kill the tasklet then disable

[Chris Wilson]

Disabling the tasklet leaves it if scheduled on the ready to run list
until it is re-enabled. This will leave the ksoftird thread spinning
until satisfied. To prevent this situation on starting the GPU reset, we
want to kill the tasklet first and then disable. The same problem will
arise when a tasklet is scheduled from another device, so a better
solution is required for the general case.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 23a17f31aa06..a8805409a3e7 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2689,8 +2689,8 @@ int i915_gem_reset_prepare(struct drm_i915_private *dev_priv)
 		 * Turning off the engine->irq_tasklet until the reset is over
 		 * prevents the race.
 		 */
-		tasklet_disable(&engine->irq_tasklet);
 		tasklet_kill(&engine->irq_tasklet);
+		tasklet_disable(&engine->irq_tasklet);
 
 		if (engine->irq_seqno_barrier)
 			engine->irq_seqno_barrier(engine);
-- 
2.11.0