diff --git a/src/drivers/intel/gma/i915.h b/src/drivers/intel/gma/i915.h
index 12a7ee02bb..9a6314e32b 100644
--- a/src/drivers/intel/gma/i915.h
+++ b/src/drivers/intel/gma/i915.h
@@ -228,7 +228,9 @@ u32 intel_ddi_calc_transcoder_flags(u32 pipe_bpp,
 				    enum pipe pipe,
 				    int type,
 				    int lane_count,
-				    int pf_sz);
+				    int pf_sz,
+				    u8 phsync,
+				    u8 pvsync);
 
 enum transcoder intel_ddi_get_transcoder(enum port port,
 					 enum pipe pipe);
diff --git a/src/drivers/intel/gma/intel_ddi.c b/src/drivers/intel/gma/intel_ddi.c
index ff8ad4cf9e..9ddd781c97 100644
--- a/src/drivers/intel/gma/intel_ddi.c
+++ b/src/drivers/intel/gma/intel_ddi.c
@@ -163,7 +163,9 @@ u32 intel_ddi_calc_transcoder_flags(u32 pipe_bpp,
 				    enum pipe pipe,
 				    int type,
 				    int lane_count,
-				    int pf_sz)
+				    int pf_sz,
+				    u8 phsync,
+				    u8 pvsync)
 {
 	u32 temp;
 
@@ -206,7 +208,11 @@ u32 intel_ddi_calc_transcoder_flags(u32 pipe_bpp,
 		}
 	}
 
-	/* We need to check for TRANS_DDI_PVSYNC and TRANS_DDI_PHSYNC -- How? */
+	if (phsync)
+		temp |= TRANS_DDI_PHSYNC;
+
+	if (pvsync)
+		temp |= TRANS_DDI_PVSYNC;
 
 	if (type == INTEL_OUTPUT_HDMI) {
 		/* Need to understand when to set TRANS_DDI_MODE_SELECT_HDMI / TRANS_DDI_MODE_SELECT_DVI */
diff --git a/src/mainboard/google/slippy/gma.c b/src/mainboard/google/slippy/gma.c
index 026bba1583..1d79d78478 100644
--- a/src/mainboard/google/slippy/gma.c
+++ b/src/mainboard/google/slippy/gma.c
@@ -293,7 +293,9 @@ void dp_init_dim_regs(struct intel_dp *dp)
 						    dp->pipe,
 						    dp->type,
 						    dp->lane_count,
-						    dp->pfa_sz);
+						    dp->pfa_sz,
+						    dp->edid.phsync == '+'?1:0,
+						    dp->edid.pvsync == '+'?1:0);
 
 	dp->transcoder = intel_ddi_get_transcoder(dp->port,
 						  dp->pipe);