1 files changed, 20 insertions, 14 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 0c201d684584..fe6538297872 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5252,21 +5252,22 @@ static void intel_unpin_work_fn(struct work_struct *__work)
 }
 
 static void do_intel_finish_page_flip(struct drm_device *dev,
-                                      struct drm_crtc *crtc,
-                                      int called_before_vblirq)
+                                      struct drm_crtc *crtc)
 {
         drm_i915_private_t *dev_priv = dev->dev_private;
         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
         struct intel_unpin_work *work;
         struct drm_i915_gem_object *obj;
         struct drm_pending_vblank_event *e;
-        struct timeval now;
+        struct timeval tnow, tvbl;
         unsigned long flags;
 
         /* Ignore early vblank irqs */
         if (intel_crtc == NULL)
                 return;
 
+        do_gettimeofday(&tnow);
+
         spin_lock_irqsave(&dev->event_lock, flags);
         work = intel_crtc->unpin_work;
         if (work == NULL || !work->pending) {
@@ -5278,22 +5279,29 @@ static void do_intel_finish_page_flip(struct drm_device *dev,
 
         if (work->event) {
                 e = work->event;
-                e->event.sequence = drm_vblank_count_and_time(dev, intel_crtc->pipe, &now);
+                e->event.sequence = drm_vblank_count_and_time(dev, intel_crtc->pipe, &tvbl);
 
                 /* Called before vblank count and timestamps have
                  * been updated for the vblank interval of flip
                  * completion? Need to increment vblank count and
                  * add one videorefresh duration to returned timestamp
-                 * to account for this.
+                 * to account for this. We assume this happened if we
+                 * get called over 0.9 frame durations after the last
+                 * timestamped vblank.
+                 *
+                 * This calculation can not be used with vrefresh rates
+                 * below 5Hz (10Hz to be on the safe side) without
+                 * promoting to 64 integers.
                  */
-                if (called_before_vblirq) {
+                if (10 * (timeval_to_ns(&tnow) - timeval_to_ns(&tvbl)) >
+                    9 * crtc->framedur_ns) {
                         e->event.sequence++;
-                        now = ns_to_timeval(timeval_to_ns(&now) +
-                                            crtc->framedur_ns);
+                        tvbl = ns_to_timeval(timeval_to_ns(&tvbl) +
+                                             crtc->framedur_ns);
                 }
 
-                e->event.tv_sec = now.tv_sec;
-                e->event.tv_usec = now.tv_usec;
+                e->event.tv_sec = tvbl.tv_sec;
+                e->event.tv_usec = tvbl.tv_usec;
 
                 list_add_tail(&e->base.link,
                               &e->base.file_priv->event_list);
@@ -5321,8 +5329,7 @@ void intel_finish_page_flip(struct drm_device *dev, int pipe)
         drm_i915_private_t *dev_priv = dev->dev_private;
         struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
 
-        /* Called after drm_handle_vblank has run for finish vblank. */
-        do_intel_finish_page_flip(dev, crtc, 0);
+        do_intel_finish_page_flip(dev, crtc);
 }
 
 void intel_finish_page_flip_plane(struct drm_device *dev, int plane)
@@ -5330,8 +5337,7 @@ void intel_finish_page_flip_plane(struct drm_device *dev, int plane)
         drm_i915_private_t *dev_priv = dev->dev_private;
         struct drm_crtc *crtc = dev_priv->plane_to_crtc_mapping[plane];
 
-        /* Called before drm_handle_vblank has run for finish vblank. */
-        do_intel_finish_page_flip(dev, crtc, 1);
+        do_intel_finish_page_flip(dev, crtc);
 }
 
 void intel_prepare_page_flip(struct drm_device *dev, int plane)