1 files changed, 6 insertions, 6 deletions

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 91e8b4c55ea0..55239d285f25 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -453,12 +453,6 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc,
         int linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
         int dotclock = mode->crtc_clock;
 
-        /* Fields of interlaced scanout modes are only half a frame duration.
-         * Double the dotclock to get half the frame-/line-/pixelduration.
-         */
-        if (mode->flags & DRM_MODE_FLAG_INTERLACE)
-                dotclock *= 2;
-
         /* Valid dotclock? */
         if (dotclock > 0) {
                 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
@@ -471,6 +465,12 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc,
                 pixeldur_ns = 1000000 / dotclock;
                 linedur_ns  = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
                 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
+
+                /*
+                 * Fields of interlaced scanout modes are only half a frame duration.
+                 */
+                if (mode->flags & DRM_MODE_FLAG_INTERLACE)
+                        framedur_ns /= 2;
         } else
                 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
                           crtc->base.id);