2 files changed, 21 insertions, 5 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index 8fc362aa6a1a..13896edcf0b6 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -285,7 +285,6 @@ static void radeon_unpin_work_func(struct work_struct *__work)
 void radeon_crtc_handle_vblank(struct radeon_device *rdev, int crtc_id)
 {
         struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc_id];
-        struct radeon_flip_work *work;
         unsigned long flags;
         u32 update_pending;
         int vpos, hpos;
@@ -295,8 +294,11 @@ void radeon_crtc_handle_vblank(struct radeon_device *rdev, int crtc_id)
                 return;
 
         spin_lock_irqsave(&rdev->ddev->event_lock, flags);
-        work = radeon_crtc->flip_work;
-        if (work == NULL) {
+        if (radeon_crtc->flip_status != RADEON_FLIP_SUBMITTED) {
+                DRM_DEBUG_DRIVER("radeon_crtc->flip_status = %d != "
+                                 "RADEON_FLIP_SUBMITTED(%d)\n",
+                                 radeon_crtc->flip_status,
+                                 RADEON_FLIP_SUBMITTED);
                 spin_unlock_irqrestore(&rdev->ddev->event_lock, flags);
                 return;
         }
@@ -344,12 +346,17 @@ void radeon_crtc_handle_flip(struct radeon_device *rdev, int crtc_id)
 
         spin_lock_irqsave(&rdev->ddev->event_lock, flags);
         work = radeon_crtc->flip_work;
-        if (work == NULL) {
+        if (radeon_crtc->flip_status != RADEON_FLIP_SUBMITTED) {
+                DRM_DEBUG_DRIVER("radeon_crtc->flip_status = %d != "
+                                 "RADEON_FLIP_SUBMITTED(%d)\n",
+                                 radeon_crtc->flip_status,
+                                 RADEON_FLIP_SUBMITTED);
                 spin_unlock_irqrestore(&rdev->ddev->event_lock, flags);
                 return;
         }
 
         /* Pageflip completed. Clean up. */
+        radeon_crtc->flip_status = RADEON_FLIP_NONE;
         radeon_crtc->flip_work = NULL;
 
         /* wakeup userspace */
@@ -476,6 +483,7 @@ static void radeon_flip_work_func(struct work_struct *__work)
         /* do the flip (mmio) */
         radeon_page_flip(rdev, radeon_crtc->crtc_id, base);
 
+        radeon_crtc->flip_status = RADEON_FLIP_SUBMITTED;
         spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
         up_read(&rdev->exclusive_lock);
 
@@ -544,7 +552,7 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
         /* We borrow the event spin lock for protecting flip_work */
         spin_lock_irqsave(&crtc->dev->event_lock, flags);
 
-        if (radeon_crtc->flip_work) {
+        if (radeon_crtc->flip_status != RADEON_FLIP_NONE) {
                 DRM_DEBUG_DRIVER("flip queue: crtc already busy\n");
                 spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
                 drm_gem_object_unreference_unlocked(&work->old_rbo->gem_base);
@@ -552,6 +560,7 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
                 kfree(work);
                 return -EBUSY;
         }
+        radeon_crtc->flip_status = RADEON_FLIP_PENDING;
         radeon_crtc->flip_work = work;
 
         /* update crtc fb */
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index 98a125d4e50b..0592ddb0904b 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -306,6 +306,12 @@ struct radeon_atom_ss {
         uint16_t amount;
 };
 
+enum radeon_flip_status {
+        RADEON_FLIP_NONE,
+        RADEON_FLIP_PENDING,
+        RADEON_FLIP_SUBMITTED
+};
+
 struct radeon_crtc {
         struct drm_crtc base;
         int crtc_id;
@@ -331,6 +337,7 @@ struct radeon_crtc {
         /* page flipping */
         struct workqueue_struct *flip_queue;
         struct radeon_flip_work *flip_work;
+        enum radeon_flip_status flip_status;
         /* pll sharing */
         struct radeon_atom_ss ss;
         bool ss_enabled;