Merge tag 'drm-intel-fixes-2017-12-14' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

drm/i915 fixes for v4.15-rc4

* tag 'drm-intel-fixes-2017-12-14' of git://anongit.freedesktop.org/drm/drm-intel:
  drm/i915/fence: Use rcu to defer freeing of irq_work
  drm/i915: Stop listening to request resubmission from the signaler kthread
  drm/i915: Drop fb reference on load_detect_pipe failure path
  drm/i915: Flush pending GTT writes before unbinding

4 files changed, 15 insertions, 22 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ad4050f7ab3b..18de6569d04a 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -330,17 +330,10 @@ int i915_gem_object_unbind(struct drm_i915_gem_object *obj)
 	 * must wait for all rendering to complete to the object (as unbinding
 	 * must anyway), and retire the requests.
 	 */
-	ret = i915_gem_object_wait(obj,
-				   I915_WAIT_INTERRUPTIBLE |
-				   I915_WAIT_LOCKED |
-				   I915_WAIT_ALL,
-				   MAX_SCHEDULE_TIMEOUT,
-				   NULL);
+	ret = i915_gem_object_set_to_cpu_domain(obj, false);
 	if (ret)
 		return ret;
 
-	i915_gem_retire_requests(to_i915(obj->base.dev));
-
 	while ((vma = list_first_entry_or_null(&obj->vma_list,
 					       struct i915_vma,
 					       obj_link))) {
diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c
index e8ca67a129d2..ac236b88c99c 100644
--- a/drivers/gpu/drm/i915/i915_sw_fence.c
+++ b/drivers/gpu/drm/i915/i915_sw_fence.c
@@ -367,6 +367,7 @@ struct i915_sw_dma_fence_cb {
 	struct dma_fence *dma;
 	struct timer_list timer;
 	struct irq_work work;
+	struct rcu_head rcu;
 };
 
 static void timer_i915_sw_fence_wake(struct timer_list *t)
@@ -406,7 +407,7 @@ static void irq_i915_sw_fence_work(struct irq_work *wrk)
 	del_timer_sync(&cb->timer);
 	dma_fence_put(cb->dma);
 
-	kfree(cb);
+	kfree_rcu(cb, rcu);
 }
 
 int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c
index 5f8b9f1f40f1..bcbc7abe6693 100644
--- a/drivers/gpu/drm/i915/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c
@@ -186,7 +186,7 @@ void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine)
 	struct intel_wait *wait, *n, *first;
 
 	if (!b->irq_armed)
-		return;
+		goto wakeup_signaler;
 
 	/* We only disarm the irq when we are idle (all requests completed),
 	 * so if the bottom-half remains asleep, it missed the request
@@ -208,6 +208,14 @@ void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine)
 	b->waiters = RB_ROOT;
 
 	spin_unlock_irq(&b->rb_lock);
+
+	/*
+	 * The signaling thread may be asleep holding a reference to a request,
+	 * that had its signaling cancelled prior to being preempted. We need
+	 * to kick the signaler, just in case, to release any such reference.
+	 */
+wakeup_signaler:
+	wake_up_process(b->signaler);
 }
 
 static bool use_fake_irq(const struct intel_breadcrumbs *b)
@@ -651,23 +659,15 @@ static int intel_breadcrumbs_signaler(void *arg)
 		}
 
 		if (unlikely(do_schedule)) {
-			DEFINE_WAIT(exec);
-
 			if (kthread_should_park())
 				kthread_parkme();
 
-			if (kthread_should_stop()) {
-				GEM_BUG_ON(request);
+			if (unlikely(kthread_should_stop())) {
+				i915_gem_request_put(request);
 				break;
 			}
 
-			if (request)
-				add_wait_queue(&request->execute, &exec);
-
 			schedule();
-
-			if (request)
-				remove_wait_queue(&request->execute, &exec);
 		}
 		i915_gem_request_put(request);
 	} while (1);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index e8ccf89cb17b..ff9397030092 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9944,11 +9944,10 @@ found:
 	}
 
 	ret = intel_modeset_setup_plane_state(state, crtc, mode, fb, 0, 0);
+	drm_framebuffer_put(fb);
 	if (ret)
 		goto fail;
 
-	drm_framebuffer_put(fb);
-
 	ret = drm_atomic_set_mode_for_crtc(&crtc_state->base, mode);
 	if (ret)
 		goto fail;