[Intel-gfx] [PATCH] drm/atomic: Handle vblank events in atomic ioctl correctly.

[Maarten Lankhorst]

All users of async updates seem to clear clear crtc_state->event
correctly, so move destroying vblank event to crtc_destroy_state.

This is better than manually free'ing it in the atomic ioctl, since
this code seems to do it wrong.

While we're at it handle -EDEADLK from atomic_commit correctly,
because the check might fail otherwise if it takes additional state.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Reviewed-by: Daniel Stone <daniels at collabora.com>
---
 drivers/gpu/drm/drm_atomic.c        | 44 +++++++++----------------------------
 drivers/gpu/drm/drm_atomic_helper.c | 15 +++++++++++++
 2 files changed, 25 insertions(+), 34 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index c7e59b074e62..097aa6d9a8c7 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1328,17 +1328,6 @@ out:
 	return e;
 }
 
-static void destroy_vblank_event(struct drm_device *dev,
-		struct drm_file *file_priv, struct drm_pending_vblank_event *e)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&dev->event_lock, flags);
-	file_priv->event_space += sizeof e->event;
-	spin_unlock_irqrestore(&dev->event_lock, flags);
-	kfree(e);
-}
-
 static int atomic_set_prop(struct drm_atomic_state *state,
 		struct drm_mode_object *obj, struct drm_property *prop,
 		uint64_t prop_value)
@@ -1534,13 +1523,18 @@ retry:
 	if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) {
 		ret = drm_atomic_check_only(state);
 		/* _check_only() does not free state, unlike _commit() */
-		drm_atomic_state_free(state);
+		if (!ret)
+			drm_atomic_state_free(state);
 	} else if (arg->flags & DRM_MODE_ATOMIC_NONBLOCK) {
 		ret = drm_atomic_async_commit(state);
 	} else {
 		ret = drm_atomic_commit(state);
 	}
 
+fail:
+	if (ret == -EDEADLK)
+		goto backoff;
+
 	/* if succeeded, fixup legacy plane crtc/fb ptrs before dropping
 	 * locks (ie. while it is still safe to deref plane->state).  We
 	 * need to do this here because the driver entry points cannot
@@ -1553,32 +1547,14 @@ retry:
 				drm_framebuffer_reference(new_fb);
 			plane->fb = new_fb;
 			plane->crtc = plane->state->crtc;
-		} else {
-			plane->old_fb = NULL;
-		}
-		if (plane->old_fb) {
-			drm_framebuffer_unreference(plane->old_fb);
-			plane->old_fb = NULL;
-		}
-	}
-
-	drm_modeset_drop_locks(&ctx);
-	drm_modeset_acquire_fini(&ctx);
 
-	return ret;
-
-fail:
-	if (ret == -EDEADLK)
-		goto backoff;
-
-	if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
-		for_each_crtc_in_state(state, crtc, crtc_state, i) {
-			destroy_vblank_event(dev, file_priv, crtc_state->event);
-			crtc_state->event = NULL;
+			drm_framebuffer_unreference(plane->old_fb);
 		}
+		plane->old_fb = NULL;
 	}
 
-	drm_atomic_state_free(state);
+	if (ret)
+		drm_atomic_state_free(state);
 
 	drm_modeset_drop_locks(&ctx);
 	drm_modeset_acquire_fini(&ctx);
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 536ae4da4665..0bb70c4da77a 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -2101,6 +2101,18 @@ drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
 }
 EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);
 
+static void destroy_vblank_event(struct drm_device *dev,
+		struct drm_pending_vblank_event *e)
+{
+	struct drm_file *file_priv = e->base.file_priv;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->event_lock, flags);
+	file_priv->event_space += sizeof e->event;
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+	kfree(e);
+}
+
 /**
  * __drm_atomic_helper_crtc_destroy_state - release CRTC state
  * @crtc: CRTC object
@@ -2115,6 +2127,9 @@ void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
 {
 	if (state->mode_blob)
 		drm_property_unreference_blob(state->mode_blob);
+
+	if (state->event)
+		destroy_vblank_event(crtc->dev, state->event);
 }
 EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
 
-- 
2.1.0