diff --git a/[refs] b/[refs]
index 0e40896ccd2e..98931e764f5c 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: dd66cc2e1f4765d0e6f39eb1e7d8d64d3f1cc522
+refs/heads/master: 85a7ce67f3ebfd5975ffd1febcabfe4999ca911d
diff --git a/trunk/drivers/gpu/drm/drm_irq.c b/trunk/drivers/gpu/drm/drm_irq.c
index 71f820565637..38e79927b2d7 100644
--- a/trunk/drivers/gpu/drm/drm_irq.c
+++ b/trunk/drivers/gpu/drm/drm_irq.c
@@ -505,6 +505,7 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc)
 
 	/* Valid dotclock? */
 	if (dotclock > 0) {
+		int frame_size;
 		/* Convert scanline length in pixels and video dot clock to
 		 * line duration, frame duration and pixel duration in
 		 * nanoseconds:
@@ -512,7 +513,10 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc)
 		pixeldur_ns = (s64) div64_u64(1000000000, dotclock);
 		linedur_ns  = (s64) div64_u64(((u64) crtc->hwmode.crtc_htotal *
 					      1000000000), dotclock);
-		framedur_ns = (s64) crtc->hwmode.crtc_vtotal * linedur_ns;
+		frame_size = crtc->hwmode.crtc_htotal *
+				crtc->hwmode.crtc_vtotal;
+		framedur_ns = (s64) div64_u64((u64) frame_size * 1000000000,
+					      dotclock);
 	} else
 		DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
 			  crtc->base.id);