1 files changed, 11 insertions, 4 deletions

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 69aa0ab28403..93e677a481f5 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -276,6 +276,7 @@ int drm_irq_uninstall(struct drm_device * dev)
         for (i = 0; i < dev->num_crtcs; i++) {
                 DRM_WAKEUP(&dev->vbl_queue[i]);
                 dev->vblank_enabled[i] = 0;
+                dev->last_vblank[i] = dev->driver->get_vblank_counter(dev, i);
         }
         spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 
@@ -434,6 +435,8 @@ EXPORT_SYMBOL(drm_vblank_get);
  */
 void drm_vblank_put(struct drm_device *dev, int crtc)
 {
+        BUG_ON (atomic_read (&dev->vblank_refcount[crtc]) == 0);
+
         /* Last user schedules interrupt disable */
         if (atomic_dec_and_test(&dev->vblank_refcount[crtc]))
                 mod_timer(&dev->vblank_disable_timer, jiffies + 5*DRM_HZ);
@@ -459,8 +462,9 @@ void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
          * so that interrupts remain enabled in the interim.
          */
         if (!dev->vblank_inmodeset[crtc]) {
-                dev->vblank_inmodeset[crtc] = 1;
-                drm_vblank_get(dev, crtc);
+                dev->vblank_inmodeset[crtc] = 0x1;
+                if (drm_vblank_get(dev, crtc) == 0)
+                        dev->vblank_inmodeset[crtc] |= 0x2;
         }
 }
 EXPORT_SYMBOL(drm_vblank_pre_modeset);
@@ -472,9 +476,12 @@ void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
         if (dev->vblank_inmodeset[crtc]) {
                 spin_lock_irqsave(&dev->vbl_lock, irqflags);
                 dev->vblank_disable_allowed = 1;
-                dev->vblank_inmodeset[crtc] = 0;
                 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
-                drm_vblank_put(dev, crtc);
+
+                if (dev->vblank_inmodeset[crtc] & 0x2)
+                        drm_vblank_put(dev, crtc);
+
+                dev->vblank_inmodeset[crtc] = 0;
         }
 }
 EXPORT_SYMBOL(drm_vblank_post_modeset);