1 files changed, 14 insertions, 12 deletions

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 3dadfa2a8528..53120a72a48c 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -164,8 +164,10 @@ static void vblank_disable_and_save(struct drm_device *dev, int crtc)
          * available. In that case we can't account for this and just
          * hope for the best.
          */
-        if ((vblrc > 0) && (abs(diff_ns) > 1000000))
+        if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) {
                 atomic_inc(&dev->_vblank_count[crtc]);
+                smp_mb__after_atomic_inc();
+        }
 
         /* Invalidate all timestamps while vblank irq's are off. */
         clear_vblank_timestamps(dev, crtc);
@@ -491,6 +493,12 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc)
         /* Dot clock in Hz: */
         dotclock = (u64) crtc->hwmode.clock * 1000;
 
+        /* Fields of interlaced scanout modes are only halve a frame duration.
+         * Double the dotclock to get halve the frame-/line-/pixelduration.
+         */
+        if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE)
+                dotclock *= 2;
+
         /* Valid dotclock? */
         if (dotclock > 0) {
                 /* Convert scanline length in pixels and video dot clock to
@@ -603,14 +611,6 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
                 return -EAGAIN;
         }
 
-        /* Don't know yet how to handle interlaced or
-         * double scan modes. Just no-op for now.
-         */
-        if (mode->flags & (DRM_MODE_FLAG_INTERLACE | DRM_MODE_FLAG_DBLSCAN)) {
-                DRM_DEBUG("crtc %d: Noop due to unsupported mode.\n", crtc);
-                return -ENOTSUPP;
-        }
-
         /* Get current scanout position with system timestamp.
          * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
          * if single query takes longer than max_error nanoseconds.
@@ -858,10 +858,11 @@ static void drm_update_vblank_count(struct drm_device *dev, int crtc)
         if (rc) {
                 tslot = atomic_read(&dev->_vblank_count[crtc]) + diff;
                 vblanktimestamp(dev, crtc, tslot) = t_vblank;
-                smp_wmb();
         }
 
+        smp_mb__before_atomic_inc();
         atomic_add(diff, &dev->_vblank_count[crtc]);
+        smp_mb__after_atomic_inc();
 }
 
 /**
@@ -1293,15 +1294,16 @@ bool drm_handle_vblank(struct drm_device *dev, int crtc)
          * e.g., due to spurious vblank interrupts. We need to
          * ignore those for accounting.
          */
-        if (abs(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
+        if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
                 /* Store new timestamp in ringbuffer. */
                 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
-                smp_wmb();
 
                 /* Increment cooked vblank count. This also atomically commits
                  * the timestamp computed above.
                  */
+                smp_mb__before_atomic_inc();
                 atomic_inc(&dev->_vblank_count[crtc]);
+                smp_mb__after_atomic_inc();
         } else {
                 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
                           crtc, (int) diff_ns);