[Intel-gfx] [PATCH 2/3] drm/i915: Call synchronize_irq() after resetting the GPU

[Chris Wilson]

When we reset the GPU, we want to reinitialise it from a known step. In
order to do so, we have to flush any pending operations from the irq
handler and its tasklets. Add a missing synchronize_irq().

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/i915_gem.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 1418c1c522cb..d037da8ea449 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2581,8 +2581,6 @@ static void i915_gem_reset_engine(struct intel_engine_cs *engine)
 	struct i915_gem_context *incomplete_ctx;
 	bool ring_hung;
 
-	/* Ensure irq handler finishes, and not run again. */
-	tasklet_kill(&engine->irq_tasklet);
 	if (engine->irq_seqno_barrier)
 		engine->irq_seqno_barrier(engine);
 
@@ -2624,6 +2622,11 @@ void i915_gem_reset(struct drm_i915_private *dev_priv)
 
 	i915_gem_retire_requests(dev_priv);
 
+	/* Ensure irq handler finishes, and not run again. */
+	synchronize_irq(dev_priv->drm.irq);
+	for_each_engine(engine, dev_priv)
+		tasklet_kill(&engine->irq_tasklet);
+
 	for_each_engine(engine, dev_priv)
 		i915_gem_reset_engine(engine);
 
-- 
2.9.3