[Intel-gfx] [PATCH 3/4] drm/i915/execlists: Assert that we don't get mixed IDLE_ACTIVE | COMPLETE events

[Chris Wilson]

If IDLE_ACTIVE is set, then all other bits are invalid. For us, we can
assert that if we see a COMPLETE | PREEMPTED event, then it should be
impossible for it to also contain an IDLE_ACTIVE flag.

Suggested-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Michal Winiarski <michal.winiarski at intel.com>
Cc: Michel Thierry <michel.thierry at intel.com>
---
 drivers/gpu/drm/i915/intel_lrc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index a2c7fc7bf4a4..4aed00323780 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -874,6 +874,9 @@ static void execlists_submission_tasklet(unsigned long data)
 			if (!(status & GEN8_CTX_STATUS_COMPLETED_MASK))
 				continue;
 
+			/* We should never get a COMPLETED | IDLE_ACTIVE! */
+			GEM_BUG_ON(status & GEN8_CTX_STATUS_IDLE_ACTIVE);
+
 			if (status & GEN8_CTX_STATUS_COMPLETE &&
 			    buf[2*head + 1] == PREEMPT_ID) {
 				execlists_cancel_port_requests(execlists);
-- 
2.15.0