[Intel-gfx] [PATCH 2/8] drm/i915/guc: Skip port assign on first iteration of GuC dequeue

[Michał Winiarski]

If port[0] is occupied and we're trying to dequeue request from
different context, we will inevitably hit BUG_ON in port_assign.
Let's skip it - similar to what we're doing in execlists counterpart.

Fixes: 77f0d0e925e8a0 ("drm/i915/execlists: Pack the count into the low bits of the port.request")
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Michał Wajdeczko <michal.wajdeczko at intel.com>
Cc: Mika Kuoppala <mika.kuoppala at intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
---
 drivers/gpu/drm/i915/i915_guc_submission.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index 777f48e..e6e0c6e 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -681,7 +681,8 @@ static bool i915_guc_dequeue(struct intel_engine_cs *engine)
 					goto done;
 				}
 
-				port_assign(port, last);
+				if (submit)
+					port_assign(port, last);
 				port++;
 			}
 
-- 
2.9.4