diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index 7316fc7fa0bd..aca26eed93b1 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
@@ -172,7 +172,7 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc)
 					mode->crtc_vsync_start - 1);
 	rcar_du_crtc_write(rcrtc, VCR,  mode->crtc_vtotal - 1);
 
-	rcar_du_crtc_write(rcrtc, DESR,  mode->htotal - mode->hsync_start);
+	rcar_du_crtc_write(rcrtc, DESR,  mode->htotal - mode->hsync_start - 1);
 	rcar_du_crtc_write(rcrtc, DEWR,  mode->hdisplay);
 }