diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index e6501143ab7cf1661deed0700d88b85d8f10d15c..d0989a85e59c9a43b65b804a71b3af0db43d7cfc 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -2837,6 +2837,8 @@ static void intel_set_transcoder_timings(const struct intel_crtc_state *crtc_sta
 	u32 crtc_vdisplay, crtc_vtotal, crtc_vblank_start, crtc_vblank_end;
 	int vsyncshift = 0;
 
+	drm_WARN_ON(&dev_priv->drm, transcoder_is_dsi(cpu_transcoder));
+
 	/* We need to be careful not to changed the adjusted mode, for otherwise
 	 * the hw state checker will get angry at the mismatch. */
 	crtc_vdisplay = adjusted_mode->crtc_vdisplay;
@@ -2918,6 +2920,8 @@ static void intel_set_transcoder_timings_lrr(const struct intel_crtc_state *crtc
 	const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
 	u32 crtc_vdisplay, crtc_vtotal, crtc_vblank_start, crtc_vblank_end;
 
+	drm_WARN_ON(&dev_priv->drm, transcoder_is_dsi(cpu_transcoder));
+
 	crtc_vdisplay = adjusted_mode->crtc_vdisplay;
 	crtc_vtotal = adjusted_mode->crtc_vtotal;
 	crtc_vblank_start = adjusted_mode->crtc_vblank_start;