1 files changed, 53 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 2151ea551d3b..607f493ae801 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -980,7 +980,8 @@ static void send_vblank_event(struct drm_device *dev,
                 struct drm_pending_vblank_event *e,
                 unsigned long seq, struct timeval *now)
 {
-        WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
+        assert_spin_locked(&dev->event_lock);
+
         e->event.sequence = seq;
         e->event.tv_sec = now->tv_sec;
         e->event.tv_usec = now->tv_usec;
@@ -993,6 +994,57 @@ static void send_vblank_event(struct drm_device *dev,
 }
 
 /**
+ * drm_arm_vblank_event - arm vblank event after pageflip
+ * @dev: DRM device
+ * @pipe: CRTC index
+ * @e: the event to prepare to send
+ *
+ * A lot of drivers need to generate vblank events for the very next vblank
+ * interrupt. For example when the page flip interrupt happens when the page
+ * flip gets armed, but not when it actually executes within the next vblank
+ * period. This helper function implements exactly the required vblank arming
+ * behaviour.
+ *
+ * Caller must hold event lock. Caller must also hold a vblank reference for
+ * the event @e, which will be dropped when the next vblank arrives.
+ *
+ * This is the legacy version of drm_crtc_arm_vblank_event().
+ */
+void drm_arm_vblank_event(struct drm_device *dev, unsigned int pipe,
+                          struct drm_pending_vblank_event *e)
+{
+        assert_spin_locked(&dev->event_lock);
+
+        e->pipe = pipe;
+        e->event.sequence = drm_vblank_count(dev, pipe);
+        list_add_tail(&e->base.link, &dev->vblank_event_list);
+}
+EXPORT_SYMBOL(drm_arm_vblank_event);
+
+/**
+ * drm_crtc_arm_vblank_event - arm vblank event after pageflip
+ * @crtc: the source CRTC of the vblank event
+ * @e: the event to send
+ *
+ * A lot of drivers need to generate vblank events for the very next vblank
+ * interrupt. For example when the page flip interrupt happens when the page
+ * flip gets armed, but not when it actually executes within the next vblank
+ * period. This helper function implements exactly the required vblank arming
+ * behaviour.
+ *
+ * Caller must hold event lock. Caller must also hold a vblank reference for
+ * the event @e, which will be dropped when the next vblank arrives.
+ *
+ * This is the native KMS version of drm_arm_vblank_event().
+ */
+void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
+                               struct drm_pending_vblank_event *e)
+{
+        drm_arm_vblank_event(crtc->dev, drm_crtc_index(crtc), e);
+}
+EXPORT_SYMBOL(drm_crtc_arm_vblank_event);
+
+/**
  * drm_send_vblank_event - helper to send vblank event after pageflip
  * @dev: DRM device
  * @pipe: CRTC index