diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index b5d87bd457bd248561abe8361dc42db341cddb15..aec569f13186455b941d48c4d89cc7bbdcebc85b 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2664,9 +2664,7 @@
 #define   DP_PRE_EMPHASIS_SHIFT		22
 
 /* How many wires to use. I guess 3 was too hard */
-#define   DP_PORT_WIDTH_1		(0 << 19)
-#define   DP_PORT_WIDTH_2		(1 << 19)
-#define   DP_PORT_WIDTH_4		(3 << 19)
+#define   DP_PORT_WIDTH(width)		(((width) - 1) << 19)
 #define   DP_PORT_WIDTH_MASK		(7 << 19)
 
 /* Mystic DPCD version 1.1 special mode */
@@ -4755,9 +4753,6 @@
 #define  TRANS_DDI_EDP_INPUT_B_ONOFF	(5<<12)
 #define  TRANS_DDI_EDP_INPUT_C_ONOFF	(6<<12)
 #define  TRANS_DDI_BFI_ENABLE		(1<<4)
-#define  TRANS_DDI_PORT_WIDTH_X1	(0<<1)
-#define  TRANS_DDI_PORT_WIDTH_X2	(1<<1)
-#define  TRANS_DDI_PORT_WIDTH_X4	(3<<1)
 
 /* DisplayPort Transport Control */
 #define DP_TP_CTL_A			0x64040
@@ -4801,9 +4796,7 @@
 #define  DDI_BUF_PORT_REVERSAL			(1<<16)
 #define  DDI_BUF_IS_IDLE			(1<<7)
 #define  DDI_A_4_LANES				(1<<4)
-#define  DDI_PORT_WIDTH_X1			(0<<1)
-#define  DDI_PORT_WIDTH_X2			(1<<1)
-#define  DDI_PORT_WIDTH_X4			(3<<1)
+#define  DDI_PORT_WIDTH(width)			(((width) - 1) << 1)
 #define  DDI_INIT_DISPLAY_DETECTED		(1<<0)
 
 /* DDI Buffer Translations */
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 72941f94c830492b6c90dcfc94cf01d39c3f0668..3ff4de6c60098f9c367c178b2929072e3f662310 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -687,22 +687,7 @@ static void intel_ddi_mode_set(struct drm_encoder *encoder,
 
 		intel_dp->DP = intel_dig_port->port_reversal |
 			       DDI_BUF_CTL_ENABLE | DDI_BUF_EMP_400MV_0DB_HSW;
-		switch (intel_dp->lane_count) {
-		case 1:
-			intel_dp->DP |= DDI_PORT_WIDTH_X1;
-			break;
-		case 2:
-			intel_dp->DP |= DDI_PORT_WIDTH_X2;
-			break;
-		case 4:
-			intel_dp->DP |= DDI_PORT_WIDTH_X4;
-			break;
-		default:
-			intel_dp->DP |= DDI_PORT_WIDTH_X4;
-			WARN(1, "Unexpected DP lane count %d\n",
-			     intel_dp->lane_count);
-			break;
-		}
+		intel_dp->DP |= DDI_PORT_WIDTH(intel_dp->lane_count);
 
 		if (intel_dp->has_audio) {
 			DRM_DEBUG_DRIVER("DP audio on pipe %c on DDI\n",
@@ -1031,22 +1016,7 @@ void intel_ddi_enable_transcoder_func(struct drm_crtc *crtc)
 
 		temp |= TRANS_DDI_MODE_SELECT_DP_SST;
 
-		switch (intel_dp->lane_count) {
-		case 1:
-			temp |= TRANS_DDI_PORT_WIDTH_X1;
-			break;
-		case 2:
-			temp |= TRANS_DDI_PORT_WIDTH_X2;
-			break;
-		case 4:
-			temp |= TRANS_DDI_PORT_WIDTH_X4;
-			break;
-		default:
-			temp |= TRANS_DDI_PORT_WIDTH_X4;
-			WARN(1, "Unsupported lane count %d\n",
-			     intel_dp->lane_count);
-		}
-
+		temp |= DDI_PORT_WIDTH(intel_dp->lane_count);
 	} else {
 		WARN(1, "Invalid encoder type %d for pipe %c\n",
 		     intel_encoder->type, pipe_name(pipe));
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 7840b4d22774fabbcd76ff8f47b7c37f6ccf9568..a2935234ac03b3406f297f0d98107750768d7268 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -891,18 +891,8 @@ intel_dp_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode,
 
 	/* Handle DP bits in common between all three register formats */
 	intel_dp->DP |= DP_VOLTAGE_0_4 | DP_PRE_EMPHASIS_0;
+	intel_dp->DP |= DP_PORT_WIDTH(intel_dp->lane_count);
 
-	switch (intel_dp->lane_count) {
-	case 1:
-		intel_dp->DP |= DP_PORT_WIDTH_1;
-		break;
-	case 2:
-		intel_dp->DP |= DP_PORT_WIDTH_2;
-		break;
-	case 4:
-		intel_dp->DP |= DP_PORT_WIDTH_4;
-		break;
-	}
 	if (intel_dp->has_audio) {
 		DRM_DEBUG_DRIVER("Enabling DP audio on pipe %c\n",
 				 pipe_name(intel_crtc->pipe));