drm/i915: Only signal from interrupt when requested

Avoid calling dma_fence_signal() from inside the interrupt if we haven't
enabled signaling on the request.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180627201304.15817-4-chris@chris-wilson.co.uk

3 files changed, 9 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index c81b4c1877cc..4be56aec99b3 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1182,7 +1182,8 @@ static void notify_ring(struct intel_engine_cs *engine)
                 if (i915_seqno_passed(seqno, wait->seqno)) {
                         struct i915_request *waiter = wait->request;
 
-                        if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
+                        if (waiter &&
+                            !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
                                       &waiter->fence.flags) &&
                             intel_wait_check_request(wait, waiter))
                                 rq = i915_request_get(waiter);
@@ -1205,8 +1206,11 @@ static void notify_ring(struct intel_engine_cs *engine)
         spin_unlock(&engine->breadcrumbs.irq_lock);
 
         if (rq) {
-                dma_fence_signal(&rq->fence);
+                spin_lock(&rq->lock);
+                dma_fence_signal_locked(&rq->fence);
                 GEM_BUG_ON(!i915_request_completed(rq));
+                spin_unlock(&rq->lock);
+
                 i915_request_put(rq);
         }
 
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 39b296878ba2..a2f7e9358450 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1285,7 +1285,7 @@ long i915_request_wait(struct i915_request *rq,
         if (flags & I915_WAIT_LOCKED)
                 add_wait_queue(errq, &reset);
 
-        intel_wait_init(&wait, rq);
+        intel_wait_init(&wait);
 
 restart:
         do {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 44ac90ec540c..78f01a35823a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -928,11 +928,10 @@ static inline u32 intel_hws_preempt_done_address(struct intel_engine_cs *engine)
 /* intel_breadcrumbs.c -- user interrupt bottom-half for waiters */
 int intel_engine_init_breadcrumbs(struct intel_engine_cs *engine);
 
-static inline void intel_wait_init(struct intel_wait *wait,
-                                   struct i915_request *rq)
+static inline void intel_wait_init(struct intel_wait *wait)
 {
         wait->tsk = current;
-        wait->request = rq;
+        wait->request = NULL;
 }
 
 static inline void intel_wait_init_for_seqno(struct intel_wait *wait, u32 seqno)