diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index af88313..952eaf7 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -125,6 +125,7 @@
 
 
 	/* XXX first guess at handling video port, is this corrent? */
+	val &= ~VIDEO_DIP_PORT_MASK;
 	if (intel_hdmi->sdvox_reg == SDVOB)
 		val |= VIDEO_DIP_PORT_B;
 	else if (intel_hdmi->sdvox_reg == SDVOC)