[PATCH 5/7] drm/i915/guc: Make submission tasklet hardirq safe

[Chris Wilson]

Prepare to allow the GuC submission to be run from underneath a
hardirq timer context (and not just the current softirq context) as is
required for fast preemption resets and context switches.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_guc_submission.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_guc_submission.c b/drivers/gpu/drm/i915/intel_guc_submission.c
index bddcf7f13123..d97d1e7c81c9 100644
--- a/drivers/gpu/drm/i915/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/intel_guc_submission.c
@@ -676,11 +676,12 @@ static void guc_dequeue(struct intel_engine_cs *engine)
 	struct i915_request *last = NULL;
 	const struct execlist_port * const last_port =
 		&execlists->port[execlists->port_mask];
+	unsigned long uninitialized_var(flags);
 	bool submit = false;
 	struct rb_node *rb;
 
 	if (!intel_engine_direct_submit(engine))
-		spin_lock_irq(&engine->timeline.lock);
+		spin_lock_irqsave(&engine->timeline.lock, flags);
 
 	rb = execlists->first;
 	GEM_BUG_ON(rb_first(&execlists->queue) != rb);
@@ -753,7 +754,7 @@ static void guc_dequeue(struct intel_engine_cs *engine)
 
 unlock:
 	if (!intel_engine_direct_submit(engine))
-		spin_unlock_irq(&engine->timeline.lock);
+		spin_unlock_irqrestore(&engine->timeline.lock, flags);
 }
 
 static void guc_submission_tasklet(unsigned long data)
-- 
2.17.0