diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 226ba83..de8db01 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -69,8 +69,7 @@ void intel_dip_infoframe_csum(struct dip_infoframe *frame)
 	frame->checksum = 0;
 	frame->ecc = 0;
 
-	/* Header isn't part of the checksum */
-	for (i = 5; i < frame->len; i++)
+	for (i = 5; i < frame->len + DIP_HEADER_SIZE; i++)
 		sum += data[i];
 
 	frame->checksum = 0x100 - sum;
@@ -167,7 +166,7 @@ static void ironlake_write_infoframe(struct drm_encoder *encoder,
 
 	val &= ~VIDEO_DIP_SELECT_MASK;
 
-	I915_WRITE(reg, val | flags);
+	I915_WRITE(reg, VIDEO_DIP_ENABLE | val | flags);
 
 	for (i = 0; i < len; i += 4) {
 		I915_WRITE(TVIDEO_DIP_DATA(intel_crtc->pipe), *data);