[Intel-gfx] [PATCH] drm/i915: Warn when execlists changes context without IRQs

[Peter Antoine]

If an batch ends while the IRQs are not turned on the notification can
go missing and the GPU can hang. So generate a warning in this case.

Signed-off-by: Peter Antoine <peter.antoine at intel.com>
---
 drivers/gpu/drm/i915/intel_lrc.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 0fa9209..0413b8f 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -394,6 +394,12 @@ static void execlists_context_unqueue(struct intel_engine_cs *ring)
 
 	assert_spin_locked(&ring->execlist_lock);
 
+	/*
+	 * If irqs are not active generate a warning as batches that finish
+	 * without the irqs may get lost and a GPU Hang may occur.
+	 */
+	WARN_ON(!intel_irqs_enabled(ring->dev->dev_private));
+
 	if (list_empty(&ring->execlist_queue))
 		return;
 
-- 
1.9.1