diff mbox series

[v5] drm/i915/icl: combo port vswing programming changes per BSPEC

Message ID 1545084827-5776-1-git-send-email-clinton.a.taylor@intel.com (mailing list archive)
State New, archived
Headers show
Series [v5] drm/i915/icl: combo port vswing programming changes per BSPEC | expand

Commit Message

Taylor, Clinton A Dec. 17, 2018, 10:13 p.m. UTC 
From: Clint Taylor <clinton.a.taylor@intel.com>

In August 2018 the BSPEC changed the ICL port programming sequence to
closely resemble earlier gen programming sequence. Restrict combo phy to
HBR max rate unless eDP panel is connected to port.

v2: remove debug code that Imre found
v3: simplify translation table if-else
v4: edp translation table now based on link rate and low_swing
v5: Misc review comments + r-b
BSpec: 21257
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Clint Taylor <clinton.a.taylor@intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h  |   4 +
 drivers/gpu/drm/i915/intel_ddi.c | 238 ++++++++++++++-------------------------
 drivers/gpu/drm/i915/intel_dp.c  |   4 +-
 3 files changed, 93 insertions(+), 153 deletions(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 0796526..02af9b5 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1884,6 +1884,10 @@  enum i915_power_well_id {
 
 #define CNL_PORT_TX_DW7_GRP(port)	_MMIO(_CNL_PORT_TX_DW_GRP((port), 7))
 #define CNL_PORT_TX_DW7_LN0(port)	_MMIO(_CNL_PORT_TX_DW_LN0((port), 7))
+#define ICL_PORT_TX_DW7_AUX(port)	_MMIO(_ICL_PORT_TX_DW_AUX(7, port))
+#define ICL_PORT_TX_DW7_GRP(port)	_MMIO(_ICL_PORT_TX_DW_GRP(7, port))
+#define ICL_PORT_TX_DW7_LN0(port)	_MMIO(_ICL_PORT_TX_DW_LN(7, 0, port))
+#define ICL_PORT_TX_DW7_LN(port, ln)	_MMIO(_ICL_PORT_TX_DW_LN(7, ln, port))
 #define   N_SCALAR(x)			((x) << 24)
 #define   N_SCALAR_MASK			(0x7F << 24)
 
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 92c0bf7..dfd3582 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -494,103 +494,58 @@  struct cnl_ddi_buf_trans {
 	{ 0x2, 0x7F, 0x3F, 0x00, 0x00 },	/* 400   400      0.0   */
 };
 
-struct icl_combo_phy_ddi_buf_trans {
-	u32 dw2_swing_select;
-	u32 dw2_swing_scalar;
-	u32 dw4_scaling;
-};
-
-/* Voltage Swing Programming for VccIO 0.85V for DP */
-static const struct icl_combo_phy_ddi_buf_trans icl_combo_phy_ddi_translations_dp_hdmi_0_85V[] = {
-				/* Voltage mV  db    */
-	{ 0x2, 0x98, 0x0018 },	/* 400         0.0   */
-	{ 0x2, 0x98, 0x3015 },	/* 400         3.5   */
-	{ 0x2, 0x98, 0x6012 },	/* 400         6.0   */
-	{ 0x2, 0x98, 0x900F },	/* 400         9.5   */
-	{ 0xB, 0x70, 0x0018 },	/* 600         0.0   */
-	{ 0xB, 0x70, 0x3015 },	/* 600         3.5   */
-	{ 0xB, 0x70, 0x6012 },	/* 600         6.0   */
-	{ 0x5, 0x00, 0x0018 },	/* 800         0.0   */
-	{ 0x5, 0x00, 0x3015 },	/* 800         3.5   */
-	{ 0x6, 0x98, 0x0018 },	/* 1200        0.0   */
-};
-
-/* FIXME - After table is updated in Bspec */
-/* Voltage Swing Programming for VccIO 0.85V for eDP */
-static const struct icl_combo_phy_ddi_buf_trans icl_combo_phy_ddi_translations_edp_0_85V[] = {
-				/* Voltage mV  db    */
-	{ 0x0, 0x00, 0x00 },	/* 200         0.0   */
-	{ 0x0, 0x00, 0x00 },	/* 200         1.5   */
-	{ 0x0, 0x00, 0x00 },	/* 200         4.0   */
-	{ 0x0, 0x00, 0x00 },	/* 200         6.0   */
-	{ 0x0, 0x00, 0x00 },	/* 250         0.0   */
-	{ 0x0, 0x00, 0x00 },	/* 250         1.5   */
-	{ 0x0, 0x00, 0x00 },	/* 250         4.0   */
-	{ 0x0, 0x00, 0x00 },	/* 300         0.0   */
-	{ 0x0, 0x00, 0x00 },	/* 300         1.5   */
-	{ 0x0, 0x00, 0x00 },	/* 350         0.0   */
-};
-
-/* Voltage Swing Programming for VccIO 0.95V for DP */
-static const struct icl_combo_phy_ddi_buf_trans icl_combo_phy_ddi_translations_dp_hdmi_0_95V[] = {
-				/* Voltage mV  db    */
-	{ 0x2, 0x98, 0x0018 },	/* 400         0.0   */
-	{ 0x2, 0x98, 0x3015 },	/* 400         3.5   */
-	{ 0x2, 0x98, 0x6012 },	/* 400         6.0   */
-	{ 0x2, 0x98, 0x900F },	/* 400         9.5   */
-	{ 0x4, 0x98, 0x0018 },	/* 600         0.0   */
-	{ 0x4, 0x98, 0x3015 },	/* 600         3.5   */
-	{ 0x4, 0x98, 0x6012 },	/* 600         6.0   */
-	{ 0x5, 0x76, 0x0018 },	/* 800         0.0   */
-	{ 0x5, 0x76, 0x3015 },	/* 800         3.5   */
-	{ 0x6, 0x98, 0x0018 },	/* 1200        0.0   */
+/* icl_combo_phy_ddi_translations */
+static const struct cnl_ddi_buf_trans icl_combo_phy_ddi_translations_dp_hbr2[] = {
+						/* NT mV Trans mV db    */
+	{ 0xA, 0x35, 0x3F, 0x00, 0x00 },	/* 350   350      0.0   */
+	{ 0xA, 0x4F, 0x37, 0x00, 0x08 },	/* 350   500      3.1   */
+	{ 0xC, 0x71, 0x2F, 0x00, 0x10 },	/* 350   700      6.0   */
+	{ 0x6, 0x7F, 0x2B, 0x00, 0x14 },	/* 350   900      8.2   */
+	{ 0xA, 0x4C, 0x3F, 0x00, 0x00 },	/* 500   500      0.0   */
+	{ 0xC, 0x73, 0x34, 0x00, 0x0B },	/* 500   700      2.9   */
+	{ 0x6, 0x7F, 0x2F, 0x00, 0x10 },	/* 500   900      5.1   */
+	{ 0xC, 0x6C, 0x3C, 0x00, 0x03 },	/* 650   700      0.6   */
+	{ 0x6, 0x7F, 0x35, 0x00, 0x0A },	/* 600   900      3.5   */
+	{ 0x6, 0x7F, 0x3F, 0x00, 0x00 },	/* 900   900      0.0   */
 };
 
-/* FIXME - After table is updated in Bspec */
-/* Voltage Swing Programming for VccIO 0.95V for eDP */
-static const struct icl_combo_phy_ddi_buf_trans icl_combo_phy_ddi_translations_edp_0_95V[] = {
-				/* Voltage mV  db    */
-	{ 0x0, 0x00, 0x00 },	/* 200         0.0   */
-	{ 0x0, 0x00, 0x00 },	/* 200         1.5   */
-	{ 0x0, 0x00, 0x00 },	/* 200         4.0   */
-	{ 0x0, 0x00, 0x00 },	/* 200         6.0   */
-	{ 0x0, 0x00, 0x00 },	/* 250         0.0   */
-	{ 0x0, 0x00, 0x00 },	/* 250         1.5   */
-	{ 0x0, 0x00, 0x00 },	/* 250         4.0   */
-	{ 0x0, 0x00, 0x00 },	/* 300         0.0   */
-	{ 0x0, 0x00, 0x00 },	/* 300         1.5   */
-	{ 0x0, 0x00, 0x00 },	/* 350         0.0   */
+static const struct cnl_ddi_buf_trans icl_combo_phy_ddi_translations_edp_hbr2[] = {
+						/* NT mV Trans mV db    */
+	{ 0x0, 0x7F, 0x3F, 0x00, 0x00 },	/* 200   200      0.0   */
+	{ 0x8, 0x7F, 0x38, 0x00, 0x07 },	/* 200   250      1.9   */
+	{ 0x1, 0x7F, 0x33, 0x00, 0x0C },	/* 200   300      3.5   */
+	{ 0x9, 0x7F, 0x31, 0x00, 0x0E },	/* 200   350      4.9   */
+	{ 0x8, 0x7F, 0x3F, 0x00, 0x00 },	/* 250   250      0.0   */
+	{ 0x1, 0x7F, 0x38, 0x00, 0x07 },	/* 250   300      1.6   */
+	{ 0x9, 0x7F, 0x35, 0x00, 0x0A },	/* 250   350      2.9   */
+	{ 0x1, 0x7F, 0x3F, 0x00, 0x00 },	/* 300   300      0.0   */
+	{ 0x9, 0x7F, 0x38, 0x00, 0x07 },	/* 300   350      1.3   */
+	{ 0x9, 0x7F, 0x3F, 0x00, 0x00 },	/* 350   350      0.0   */
 };
 
-/* Voltage Swing Programming for VccIO 1.05V for DP */
-static const struct icl_combo_phy_ddi_buf_trans icl_combo_phy_ddi_translations_dp_hdmi_1_05V[] = {
-				/* Voltage mV  db    */
-	{ 0x2, 0x98, 0x0018 },	/* 400         0.0   */
-	{ 0x2, 0x98, 0x3015 },	/* 400         3.5   */
-	{ 0x2, 0x98, 0x6012 },	/* 400         6.0   */
-	{ 0x2, 0x98, 0x900F },	/* 400         9.5   */
-	{ 0x4, 0x98, 0x0018 },	/* 600         0.0   */
-	{ 0x4, 0x98, 0x3015 },	/* 600         3.5   */
-	{ 0x4, 0x98, 0x6012 },	/* 600         6.0   */
-	{ 0x5, 0x71, 0x0018 },	/* 800         0.0   */
-	{ 0x5, 0x71, 0x3015 },	/* 800         3.5   */
-	{ 0x6, 0x98, 0x0018 },	/* 1200        0.0   */
+static const struct cnl_ddi_buf_trans icl_combo_phy_ddi_translations_edp_hbr3[] = {
+						/* NT mV Trans mV db    */
+	{ 0xA, 0x35, 0x3F, 0x00, 0x00 },	/* 350   350      0.0   */
+	{ 0xA, 0x4F, 0x37, 0x00, 0x08 },	/* 350   500      3.1   */
+	{ 0xC, 0x71, 0x2F, 0x00, 0x10 },	/* 350   700      6.0   */
+	{ 0x6, 0x7F, 0x2B, 0x00, 0x14 },	/* 350   900      8.2   */
+	{ 0xA, 0x4C, 0x3F, 0x00, 0x00 },	/* 500   500      0.0   */
+	{ 0xC, 0x73, 0x34, 0x00, 0x0B },	/* 500   700      2.9   */
+	{ 0x6, 0x7F, 0x2F, 0x00, 0x10 },	/* 500   900      5.1   */
+	{ 0xC, 0x6C, 0x3C, 0x00, 0x03 },	/* 650   700      0.6   */
+	{ 0x6, 0x7F, 0x35, 0x00, 0x0A },	/* 600   900      3.5   */
+	{ 0x6, 0x7F, 0x3F, 0x00, 0x00 },	/* 900   900      0.0   */
 };
 
-/* FIXME - After table is updated in Bspec */
-/* Voltage Swing Programming for VccIO 1.05V for eDP */
-static const struct icl_combo_phy_ddi_buf_trans icl_combo_phy_ddi_translations_edp_1_05V[] = {
-				/* Voltage mV  db    */
-	{ 0x0, 0x00, 0x00 },	/* 200         0.0   */
-	{ 0x0, 0x00, 0x00 },	/* 200         1.5   */
-	{ 0x0, 0x00, 0x00 },	/* 200         4.0   */
-	{ 0x0, 0x00, 0x00 },	/* 200         6.0   */
-	{ 0x0, 0x00, 0x00 },	/* 250         0.0   */
-	{ 0x0, 0x00, 0x00 },	/* 250         1.5   */
-	{ 0x0, 0x00, 0x00 },	/* 250         4.0   */
-	{ 0x0, 0x00, 0x00 },	/* 300         0.0   */
-	{ 0x0, 0x00, 0x00 },	/* 300         1.5   */
-	{ 0x0, 0x00, 0x00 },	/* 350         0.0   */
+static const struct cnl_ddi_buf_trans icl_combo_phy_ddi_translations_hdmi[] = {
+						/* NT mV Trans mV db    */
+	{ 0xA, 0x60, 0x3F, 0x00, 0x00 },	/* 450   450      0.0   */
+	{ 0xB, 0x73, 0x36, 0x00, 0x09 },	/* 450   650      3.2   */
+	{ 0x6, 0x7F, 0x31, 0x00, 0x0E },	/* 450   850      5.5   */
+	{ 0xB, 0x73, 0x3F, 0x00, 0x00 },	/* 650   650      0.0   ALS */
+	{ 0x6, 0x7F, 0x37, 0x00, 0x08 },	/* 650   850      2.3   */
+	{ 0x6, 0x7F, 0x3F, 0x00, 0x00 },	/* 850   850      0.0   */
+	{ 0x6, 0x7F, 0x35, 0x00, 0x0A },	/* 600   850      3.0   */
 };
 
 struct icl_mg_phy_ddi_buf_trans {
@@ -871,43 +826,23 @@  static int skl_buf_trans_num_entries(enum port port, int n_entries)
 	}
 }
 
-static const struct icl_combo_phy_ddi_buf_trans *
+static const struct cnl_ddi_buf_trans *
 icl_get_combo_buf_trans(struct drm_i915_private *dev_priv, enum port port,
-			int type, int *n_entries)
+			int type, int rate, int *n_entries)
 {
-	u32 voltage = I915_READ(ICL_PORT_COMP_DW3(port)) & VOLTAGE_INFO_MASK;
-
-	if (type == INTEL_OUTPUT_EDP && dev_priv->vbt.edp.low_vswing) {
-		switch (voltage) {
-		case VOLTAGE_INFO_0_85V:
-			*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_edp_0_85V);
-			return icl_combo_phy_ddi_translations_edp_0_85V;
-		case VOLTAGE_INFO_0_95V:
-			*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_edp_0_95V);
-			return icl_combo_phy_ddi_translations_edp_0_95V;
-		case VOLTAGE_INFO_1_05V:
-			*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_edp_1_05V);
-			return icl_combo_phy_ddi_translations_edp_1_05V;
-		default:
-			MISSING_CASE(voltage);
-			return NULL;
-		}
-	} else {
-		switch (voltage) {
-		case VOLTAGE_INFO_0_85V:
-			*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_dp_hdmi_0_85V);
-			return icl_combo_phy_ddi_translations_dp_hdmi_0_85V;
-		case VOLTAGE_INFO_0_95V:
-			*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_dp_hdmi_0_95V);
-			return icl_combo_phy_ddi_translations_dp_hdmi_0_95V;
-		case VOLTAGE_INFO_1_05V:
-			*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_dp_hdmi_1_05V);
-			return icl_combo_phy_ddi_translations_dp_hdmi_1_05V;
-		default:
-			MISSING_CASE(voltage);
-			return NULL;
-		}
+	if (type == INTEL_OUTPUT_HDMI) {
+		*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_hdmi);
+		return icl_combo_phy_ddi_translations_hdmi;
+	} else if (rate > 540000 && type == INTEL_OUTPUT_EDP) {
+		*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_edp_hbr3);
+		return icl_combo_phy_ddi_translations_edp_hbr3;
+	} else if (type == INTEL_OUTPUT_EDP && dev_priv->vbt.edp.low_vswing) {
+		*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_edp_hbr2);
+		return icl_combo_phy_ddi_translations_edp_hbr2;
 	}
+
+	*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_dp_hbr2);
+	return icl_combo_phy_ddi_translations_dp_hbr2;
 }
 
 static int intel_ddi_hdmi_level(struct drm_i915_private *dev_priv, enum port port)
@@ -918,8 +853,8 @@  static int intel_ddi_hdmi_level(struct drm_i915_private *dev_priv, enum port por
 
 	if (IS_ICELAKE(dev_priv)) {
 		if (intel_port_is_combophy(dev_priv, port))
-			icl_get_combo_buf_trans(dev_priv, port,
-						INTEL_OUTPUT_HDMI, &n_entries);
+			icl_get_combo_buf_trans(dev_priv, port, INTEL_OUTPUT_HDMI,
+						0, &n_entries);
 		else
 			n_entries = ARRAY_SIZE(icl_mg_phy_ddi_translations);
 		default_entry = n_entries - 1;
@@ -2275,13 +2210,14 @@  static void bxt_ddi_vswing_sequence(struct intel_encoder *encoder,
 u8 intel_ddi_dp_voltage_max(struct intel_encoder *encoder)
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
 	enum port port = encoder->port;
 	int n_entries;
 
 	if (IS_ICELAKE(dev_priv)) {
 		if (intel_port_is_combophy(dev_priv, port))
 			icl_get_combo_buf_trans(dev_priv, port, encoder->type,
-						&n_entries);
+						intel_dp->link_rate, &n_entries);
 		else
 			n_entries = ARRAY_SIZE(icl_mg_phy_ddi_translations);
 	} else if (IS_CANNONLAKE(dev_priv)) {
@@ -2462,14 +2398,15 @@  static void cnl_ddi_vswing_sequence(struct intel_encoder *encoder,
 }
 
 static void icl_ddi_combo_vswing_program(struct drm_i915_private *dev_priv,
-					 u32 level, enum port port, int type)
+					u32 level, enum port port, int type,
+					int rate)
 {
-	const struct icl_combo_phy_ddi_buf_trans *ddi_translations = NULL;
+	const struct cnl_ddi_buf_trans *ddi_translations = NULL;
 	u32 n_entries, val;
 	int ln;
 
 	ddi_translations = icl_get_combo_buf_trans(dev_priv, port, type,
-						   &n_entries);
+						   rate, &n_entries);
 	if (!ddi_translations)
 		return;
 
@@ -2478,34 +2415,23 @@  static void icl_ddi_combo_vswing_program(struct drm_i915_private *dev_priv,
 		level = n_entries - 1;
 	}
 
-	/* Set PORT_TX_DW5 Rterm Sel to 110b. */
+	/* Set PORT_TX_DW5 */
 	val = I915_READ(ICL_PORT_TX_DW5_LN0(port));
-	val &= ~RTERM_SELECT_MASK;
+	val &= ~(SCALING_MODE_SEL_MASK | RTERM_SELECT_MASK |
+		  TAP2_DISABLE | TAP3_DISABLE);
+	val |= SCALING_MODE_SEL(0x2);
 	val |= RTERM_SELECT(0x6);
-	I915_WRITE(ICL_PORT_TX_DW5_GRP(port), val);
-
-	/* Program PORT_TX_DW5 */
-	val = I915_READ(ICL_PORT_TX_DW5_LN0(port));
-	/* Set DisableTap2 and DisableTap3 if MIPI DSI
-	 * Clear DisableTap2 and DisableTap3 for all other Ports
-	 */
-	if (type == INTEL_OUTPUT_DSI) {
-		val |= TAP2_DISABLE;
-		val |= TAP3_DISABLE;
-	} else {
-		val &= ~TAP2_DISABLE;
-		val &= ~TAP3_DISABLE;
-	}
+	val |= TAP3_DISABLE;
 	I915_WRITE(ICL_PORT_TX_DW5_GRP(port), val);
 
 	/* Program PORT_TX_DW2 */
 	val = I915_READ(ICL_PORT_TX_DW2_LN0(port));
 	val &= ~(SWING_SEL_LOWER_MASK | SWING_SEL_UPPER_MASK |
 		 RCOMP_SCALAR_MASK);
-	val |= SWING_SEL_UPPER(ddi_translations[level].dw2_swing_select);
-	val |= SWING_SEL_LOWER(ddi_translations[level].dw2_swing_select);
+	val |= SWING_SEL_UPPER(ddi_translations[level].dw2_swing_sel);
+	val |= SWING_SEL_LOWER(ddi_translations[level].dw2_swing_sel);
 	/* Program Rcomp scalar for every table entry */
-	val |= RCOMP_SCALAR(ddi_translations[level].dw2_swing_scalar);
+	val |= RCOMP_SCALAR(0x98);
 	I915_WRITE(ICL_PORT_TX_DW2_GRP(port), val);
 
 	/* Program PORT_TX_DW4 */
@@ -2514,9 +2440,17 @@  static void icl_ddi_combo_vswing_program(struct drm_i915_private *dev_priv,
 		val = I915_READ(ICL_PORT_TX_DW4_LN(port, ln));
 		val &= ~(POST_CURSOR_1_MASK | POST_CURSOR_2_MASK |
 			 CURSOR_COEFF_MASK);
-		val |= ddi_translations[level].dw4_scaling;
+		val |= POST_CURSOR_1(ddi_translations[level].dw4_post_cursor_1);
+		val |= POST_CURSOR_2(ddi_translations[level].dw4_post_cursor_2);
+		val |= CURSOR_COEFF(ddi_translations[level].dw4_cursor_coeff);
 		I915_WRITE(ICL_PORT_TX_DW4_LN(port, ln), val);
 	}
+
+	/* Program PORT_TX_DW7 */
+	val = I915_READ(ICL_PORT_TX_DW7_LN0(port));
+	val &= ~N_SCALAR_MASK;
+	val |= N_SCALAR(ddi_translations[level].dw7_n_scalar);
+	I915_WRITE(ICL_PORT_TX_DW7_GRP(port), val);
 }
 
 static void icl_combo_phy_ddi_vswing_sequence(struct intel_encoder *encoder,
@@ -2581,7 +2515,7 @@  static void icl_combo_phy_ddi_vswing_sequence(struct intel_encoder *encoder,
 	I915_WRITE(ICL_PORT_TX_DW5_GRP(port), val);
 
 	/* 5. Program swing and de-emphasis */
-	icl_ddi_combo_vswing_program(dev_priv, level, port, type);
+	icl_ddi_combo_vswing_program(dev_priv, level, port, type, rate);
 
 	/* 6. Set training enable to trigger update */
 	val = I915_READ(ICL_PORT_TX_DW5_LN0(port));
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 62484e1..9b76c23 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -304,9 +304,11 @@  static int cnl_max_source_rate(struct intel_dp *intel_dp)
 static int icl_max_source_rate(struct intel_dp *intel_dp)
 {
 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
 	enum port port = dig_port->base.port;
 
-	if (port == PORT_B)
+	if (intel_port_is_combophy(dev_priv, port) &&
+	    !intel_dp_is_edp(intel_dp))
 		return 540000;
 
 	return 810000;