diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index bd987935d9c9..1e15ffa79295 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -941,6 +941,22 @@ int tb_port_get_link_generation(struct tb_port *port)
 	}
 }
 
+static const char *width_name(enum tb_link_width width)
+{
+	switch (width) {
+	case TB_LINK_WIDTH_SINGLE:
+		return "symmetric, single lane";
+	case TB_LINK_WIDTH_DUAL:
+		return "symmetric, dual lanes";
+	case TB_LINK_WIDTH_ASYM_TX:
+		return "asymmetric, 3 transmitters, 1 receiver";
+	case TB_LINK_WIDTH_ASYM_RX:
+		return "asymmetric, 3 receivers, 1 transmitter";
+	default:
+		return "unknown";
+	}
+}
+
 /**
  * tb_port_get_link_width() - Get current link width
  * @port: Port to check (USB4 or CIO)
@@ -966,8 +982,15 @@ int tb_port_get_link_width(struct tb_port *port)
 		LANE_ADP_CS_1_CURRENT_WIDTH_SHIFT;
 }
 
-static bool tb_port_is_width_supported(struct tb_port *port,
-				       unsigned int width_mask)
+/**
+ * tb_port_width_supported() - Is the given link width supported
+ * @port: Port to check
+ * @width: Widths to check (bitmask)
+ *
+ * Can be called to any lane adapter. Checks if given @width is
+ * supported by the hardware and returns %true if it is.
+ */
+bool tb_port_width_supported(struct tb_port *port, unsigned int width)
 {
 	u32 phy, widths;
 	int ret;
@@ -975,15 +998,23 @@ static bool tb_port_is_width_supported(struct tb_port *port,
 	if (!port->cap_phy)
 		return false;
 
+	if (width & (TB_LINK_WIDTH_ASYM_TX | TB_LINK_WIDTH_ASYM_RX)) {
+		if (tb_port_get_link_generation(port) < 4 ||
+		    !usb4_port_asym_supported(port))
+			return false;
+	}
+
 	ret = tb_port_read(port, &phy, TB_CFG_PORT,
 			   port->cap_phy + LANE_ADP_CS_0, 1);
 	if (ret)
 		return false;
 
-	widths = (phy & LANE_ADP_CS_0_SUPPORTED_WIDTH_MASK) >>
-		LANE_ADP_CS_0_SUPPORTED_WIDTH_SHIFT;
-
-	return widths & width_mask;
+	/*
+	 * The field encoding is the same as &enum tb_link_width (which is
+	 * passed to @width).
+	 */
+	widths = FIELD_GET(LANE_ADP_CS_0_SUPPORTED_WIDTH_MASK, phy);
+	return widths & width;
 }
 
 /**
@@ -1018,10 +1049,18 @@ int tb_port_set_link_width(struct tb_port *port, enum tb_link_width width)
 		val |= LANE_ADP_CS_1_TARGET_WIDTH_SINGLE <<
 			LANE_ADP_CS_1_TARGET_WIDTH_SHIFT;
 		break;
+
 	case TB_LINK_WIDTH_DUAL:
+		if (tb_port_get_link_generation(port) >= 4)
+			return usb4_port_asym_set_link_width(port, width);
 		val |= LANE_ADP_CS_1_TARGET_WIDTH_DUAL <<
 			LANE_ADP_CS_1_TARGET_WIDTH_SHIFT;
 		break;
+
+	case TB_LINK_WIDTH_ASYM_TX:
+	case TB_LINK_WIDTH_ASYM_RX:
+		return usb4_port_asym_set_link_width(port, width);
+
 	default:
 		return -EINVAL;
 	}
@@ -1146,7 +1185,7 @@ void tb_port_lane_bonding_disable(struct tb_port *port)
 /**
  * tb_port_wait_for_link_width() - Wait until link reaches specific width
  * @port: Port to wait for
- * @width_mask: Expected link width mask
+ * @width: Expected link width (bitmask)
  * @timeout_msec: Timeout in ms how long to wait
  *
  * Should be used after both ends of the link have been bonded (or
@@ -1155,14 +1194,14 @@ void tb_port_lane_bonding_disable(struct tb_port *port)
  * within the given timeout, %0 if it did. Can be passed a mask of
  * expected widths and succeeds if any of the widths is reached.
  */
-int tb_port_wait_for_link_width(struct tb_port *port, unsigned int width_mask,
+int tb_port_wait_for_link_width(struct tb_port *port, unsigned int width,
 				int timeout_msec)
 {
 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
 	int ret;
 
 	/* Gen 4 link does not support single lane */
-	if ((width_mask & TB_LINK_WIDTH_SINGLE) &&
+	if ((width & TB_LINK_WIDTH_SINGLE) &&
 	    tb_port_get_link_generation(port) >= 4)
 		return -EOPNOTSUPP;
 
@@ -1176,7 +1215,7 @@ int tb_port_wait_for_link_width(struct tb_port *port, unsigned int width_mask,
 			 */
 			if (ret != -EACCES)
 				return ret;
-		} else if (ret & width_mask) {
+		} else if (ret & width) {
 			return 0;
 		}
 
@@ -2720,6 +2759,38 @@ static int tb_switch_update_link_attributes(struct tb_switch *sw)
 	return 0;
 }
 
+/* Must be called after tb_switch_update_link_attributes() */
+static void tb_switch_link_init(struct tb_switch *sw)
+{
+	struct tb_port *up, *down;
+	bool bonded;
+
+	if (!tb_route(sw) || tb_switch_is_icm(sw))
+		return;
+
+	tb_sw_dbg(sw, "current link speed %u.0 Gb/s\n", sw->link_speed);
+	tb_sw_dbg(sw, "current link width %s\n", width_name(sw->link_width));
+
+	bonded = sw->link_width >= TB_LINK_WIDTH_DUAL;
+
+	/*
+	 * Gen 4 links come up as bonded so update the port structures
+	 * accordingly.
+	 */
+	up = tb_upstream_port(sw);
+	down = tb_switch_downstream_port(sw);
+
+	up->bonded = bonded;
+	if (up->dual_link_port)
+		up->dual_link_port->bonded = bonded;
+	tb_port_update_credits(up);
+
+	down->bonded = bonded;
+	if (down->dual_link_port)
+		down->dual_link_port->bonded = bonded;
+	tb_port_update_credits(down);
+}
+
 /**
  * tb_switch_lane_bonding_enable() - Enable lane bonding
  * @sw: Switch to enable lane bonding
@@ -2728,24 +2799,20 @@ static int tb_switch_update_link_attributes(struct tb_switch *sw)
  * switch. If conditions are correct and both switches support the feature,
  * lanes are bonded. It is safe to call this to any switch.
  */
-int tb_switch_lane_bonding_enable(struct tb_switch *sw)
+static int tb_switch_lane_bonding_enable(struct tb_switch *sw)
 {
 	struct tb_port *up, *down;
-	u64 route = tb_route(sw);
-	unsigned int width_mask;
+	unsigned int width;
 	int ret;
 
-	if (!route)
-		return 0;
-
 	if (!tb_switch_lane_bonding_possible(sw))
 		return 0;
 
 	up = tb_upstream_port(sw);
 	down = tb_switch_downstream_port(sw);
 
-	if (!tb_port_is_width_supported(up, TB_LINK_WIDTH_DUAL) ||
-	    !tb_port_is_width_supported(down, TB_LINK_WIDTH_DUAL))
+	if (!tb_port_width_supported(up, TB_LINK_WIDTH_DUAL) ||
+	    !tb_port_width_supported(down, TB_LINK_WIDTH_DUAL))
 		return 0;
 
 	/*
@@ -2769,21 +2836,10 @@ int tb_switch_lane_bonding_enable(struct tb_switch *sw)
 	}
 
 	/* Any of the widths are all bonded */
-	width_mask = TB_LINK_WIDTH_DUAL | TB_LINK_WIDTH_ASYM_TX |
-		     TB_LINK_WIDTH_ASYM_RX;
+	width = TB_LINK_WIDTH_DUAL | TB_LINK_WIDTH_ASYM_TX |
+		TB_LINK_WIDTH_ASYM_RX;
 
-	ret = tb_port_wait_for_link_width(down, width_mask, 100);
-	if (ret) {
-		tb_port_warn(down, "timeout enabling lane bonding\n");
-		return ret;
-	}
-
-	tb_port_update_credits(down);
-	tb_port_update_credits(up);
-	tb_switch_update_link_attributes(sw);
-
-	tb_sw_dbg(sw, "lane bonding enabled\n");
-	return ret;
+	return tb_port_wait_for_link_width(down, width, 100);
 }
 
 /**
@@ -2793,20 +2849,27 @@ int tb_switch_lane_bonding_enable(struct tb_switch *sw)
  * Disables lane bonding between @sw and parent. This can be called even
  * if lanes were not bonded originally.
  */
-void tb_switch_lane_bonding_disable(struct tb_switch *sw)
+static int tb_switch_lane_bonding_disable(struct tb_switch *sw)
 {
 	struct tb_port *up, *down;
 	int ret;
 
-	if (!tb_route(sw))
-		return;
-
 	up = tb_upstream_port(sw);
 	if (!up->bonded)
-		return;
+		return 0;
 
-	down = tb_switch_downstream_port(sw);
+	/*
+	 * If the link is Gen 4 there is no way to switch the link to
+	 * two single lane links so avoid that here. Also don't bother
+	 * if the link is not up anymore (sw is unplugged).
+	 */
+	ret = tb_port_get_link_generation(up);
+	if (ret < 0)
+		return ret;
+	if (ret >= 4)
+		return -EOPNOTSUPP;
 
+	down = tb_switch_downstream_port(sw);
 	tb_port_lane_bonding_disable(up);
 	tb_port_lane_bonding_disable(down);
 
@@ -2814,15 +2877,160 @@ void tb_switch_lane_bonding_disable(struct tb_switch *sw)
 	 * It is fine if we get other errors as the router might have
 	 * been unplugged.
 	 */
-	ret = tb_port_wait_for_link_width(down, TB_LINK_WIDTH_SINGLE, 100);
-	if (ret == -ETIMEDOUT)
-		tb_sw_warn(sw, "timeout disabling lane bonding\n");
+	return tb_port_wait_for_link_width(down, TB_LINK_WIDTH_SINGLE, 100);
+}
+
+static int tb_switch_asym_enable(struct tb_switch *sw, enum tb_link_width width)
+{
+	struct tb_port *up, *down, *port;
+	enum tb_link_width down_width;
+	int ret;
+
+	up = tb_upstream_port(sw);
+	down = tb_switch_downstream_port(sw);
+
+	if (width == TB_LINK_WIDTH_ASYM_TX) {
+		down_width = TB_LINK_WIDTH_ASYM_RX;
+		port = down;
+	} else {
+		down_width = TB_LINK_WIDTH_ASYM_TX;
+		port = up;
+	}
+
+	ret = tb_port_set_link_width(up, width);
+	if (ret)
+		return ret;
+
+	ret = tb_port_set_link_width(down, down_width);
+	if (ret)
+		return ret;
+
+	/*
+	 * Initiate the change in the router that one of its TX lanes is
+	 * changing to RX but do so only if there is an actual change.
+	 */
+	if (sw->link_width != width) {
+		ret = usb4_port_asym_start(port);
+		if (ret)
+			return ret;
+
+		ret = tb_port_wait_for_link_width(up, width, 100);
+		if (ret)
+			return ret;
+	}
+
+	sw->link_width = width;
+	return 0;
+}
+
+static int tb_switch_asym_disable(struct tb_switch *sw)
+{
+	struct tb_port *up, *down;
+	int ret;
+
+	up = tb_upstream_port(sw);
+	down = tb_switch_downstream_port(sw);
+
+	ret = tb_port_set_link_width(up, TB_LINK_WIDTH_DUAL);
+	if (ret)
+		return ret;
+
+	ret = tb_port_set_link_width(down, TB_LINK_WIDTH_DUAL);
+	if (ret)
+		return ret;
+
+	/*
+	 * Initiate the change in the router that has three TX lanes and
+	 * is changing one of its TX lanes to RX but only if there is a
+	 * change in the link width.
+	 */
+	if (sw->link_width > TB_LINK_WIDTH_DUAL) {
+		if (sw->link_width == TB_LINK_WIDTH_ASYM_TX)
+			ret = usb4_port_asym_start(up);
+		else
+			ret = usb4_port_asym_start(down);
+		if (ret)
+			return ret;
+
+		ret = tb_port_wait_for_link_width(up, TB_LINK_WIDTH_DUAL, 100);
+		if (ret)
+			return ret;
+	}
+
+	sw->link_width = TB_LINK_WIDTH_DUAL;
+	return 0;
+}
+
+/**
+ * tb_switch_set_link_width() - Configure router link width
+ * @sw: Router to configure
+ * @width: The new link width
+ *
+ * Set device router link width to @width from router upstream port
+ * perspective. Supports also asymmetric links if the routers boths side
+ * of the link supports it.
+ *
+ * Does nothing for host router.
+ *
+ * Returns %0 in case of success, negative errno otherwise.
+ */
+int tb_switch_set_link_width(struct tb_switch *sw, enum tb_link_width width)
+{
+	struct tb_port *up, *down;
+	int ret = 0;
+
+	if (!tb_route(sw))
+		return 0;
+
+	up = tb_upstream_port(sw);
+	down = tb_switch_downstream_port(sw);
+
+	switch (width) {
+	case TB_LINK_WIDTH_SINGLE:
+		ret = tb_switch_lane_bonding_disable(sw);
+		break;
+
+	case TB_LINK_WIDTH_DUAL:
+		if (sw->link_width == TB_LINK_WIDTH_ASYM_TX ||
+		    sw->link_width == TB_LINK_WIDTH_ASYM_RX) {
+			ret = tb_switch_asym_disable(sw);
+			if (ret)
+				break;
+		}
+		ret = tb_switch_lane_bonding_enable(sw);
+		break;
+
+	case TB_LINK_WIDTH_ASYM_TX:
+	case TB_LINK_WIDTH_ASYM_RX:
+		ret = tb_switch_asym_enable(sw, width);
+		break;
+	}
+
+	switch (ret) {
+	case 0:
+		break;
+
+	case -ETIMEDOUT:
+		tb_sw_warn(sw, "timeout changing link width\n");
+		return ret;
+
+	case -ENOTCONN:
+	case -EOPNOTSUPP:
+	case -ENODEV:
+		return ret;
+
+	default:
+		tb_sw_dbg(sw, "failed to change link width: %d\n", ret);
+		return ret;
+	}
 
 	tb_port_update_credits(down);
 	tb_port_update_credits(up);
+
 	tb_switch_update_link_attributes(sw);
 
-	tb_sw_dbg(sw, "lane bonding disabled\n");
+	tb_sw_dbg(sw, "link width set to %s\n", width_name(width));
+	return ret;
 }
 
 /**
@@ -2982,6 +3190,8 @@ int tb_switch_add(struct tb_switch *sw)
 		if (ret)
 			return ret;
 
+		tb_switch_link_init(sw);
+
 		ret = tb_switch_clx_init(sw);
 		if (ret)
 			return ret;
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 9efe0b1435e8..67c56337a4d2 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -985,7 +985,7 @@ static void tb_scan_port(struct tb_port *port)
 	}
 
 	/* Enable lane bonding if supported */
-	tb_switch_lane_bonding_enable(sw);
+	tb_switch_set_link_width(sw, TB_LINK_WIDTH_DUAL);
 	/* Set the link configured */
 	tb_switch_configure_link(sw);
 	/*
@@ -1103,7 +1103,8 @@ static void tb_free_unplugged_children(struct tb_switch *sw)
 			tb_retimer_remove_all(port);
 			tb_remove_dp_resources(port->remote->sw);
 			tb_switch_unconfigure_link(port->remote->sw);
-			tb_switch_lane_bonding_disable(port->remote->sw);
+			tb_switch_set_link_width(port->remote->sw,
+						 TB_LINK_WIDTH_SINGLE);
 			tb_switch_remove(port->remote->sw);
 			port->remote = NULL;
 			if (port->dual_link_port)
@@ -1721,7 +1722,8 @@ static void tb_handle_hotplug(struct work_struct *work)
 			tb_remove_dp_resources(port->remote->sw);
 			tb_switch_tmu_disable(port->remote->sw);
 			tb_switch_unconfigure_link(port->remote->sw);
-			tb_switch_lane_bonding_disable(port->remote->sw);
+			tb_switch_set_link_width(port->remote->sw,
+						 TB_LINK_WIDTH_SINGLE);
 			tb_switch_remove(port->remote->sw);
 			port->remote = NULL;
 			if (port->dual_link_port)
@@ -2205,7 +2207,8 @@ static void tb_restore_children(struct tb_switch *sw)
 			continue;
 
 		if (port->remote) {
-			tb_switch_lane_bonding_enable(port->remote->sw);
+			tb_switch_set_link_width(port->remote->sw,
+						 port->remote->sw->link_width);
 			tb_switch_configure_link(port->remote->sw);
 
 			tb_restore_children(port->remote->sw);
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 80e28124f583..e299e53473ae 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -162,11 +162,6 @@ struct tb_switch_tmu {
  * switches) you need to have domain lock held.
  *
  * In USB4 terminology this structure represents a router.
- *
- * Note @link_width is not the same as whether link is bonded or not.
- * For Gen 4 links the link is also bonded when it is asymmetric. The
- * correct way to find out whether the link is bonded or not is to look
- * @bonded field of the upstream port.
  */
 struct tb_switch {
 	struct device dev;
@@ -967,8 +962,7 @@ static inline bool tb_switch_is_icm(const struct tb_switch *sw)
 	return !sw->config.enabled;
 }
 
-int tb_switch_lane_bonding_enable(struct tb_switch *sw);
-void tb_switch_lane_bonding_disable(struct tb_switch *sw);
+int tb_switch_set_link_width(struct tb_switch *sw, enum tb_link_width width);
 int tb_switch_configure_link(struct tb_switch *sw);
 void tb_switch_unconfigure_link(struct tb_switch *sw);
 
@@ -1100,10 +1094,11 @@ static inline bool tb_port_use_credit_allocation(const struct tb_port *port)
 int tb_port_get_link_speed(struct tb_port *port);
 int tb_port_get_link_generation(struct tb_port *port);
 int tb_port_get_link_width(struct tb_port *port);
+bool tb_port_width_supported(struct tb_port *port, unsigned int width);
 int tb_port_set_link_width(struct tb_port *port, enum tb_link_width width);
 int tb_port_lane_bonding_enable(struct tb_port *port);
 void tb_port_lane_bonding_disable(struct tb_port *port);
-int tb_port_wait_for_link_width(struct tb_port *port, unsigned int width_mask,
+int tb_port_wait_for_link_width(struct tb_port *port, unsigned int width,
 				int timeout_msec);
 int tb_port_update_credits(struct tb_port *port);
 
@@ -1297,6 +1292,11 @@ int usb4_port_router_online(struct tb_port *port);
 int usb4_port_enumerate_retimers(struct tb_port *port);
 bool usb4_port_clx_supported(struct tb_port *port);
 int usb4_port_margining_caps(struct tb_port *port, u32 *caps);
+
+bool usb4_port_asym_supported(struct tb_port *port);
+int usb4_port_asym_set_link_width(struct tb_port *port, enum tb_link_width width);
+int usb4_port_asym_start(struct tb_port *port);
+
 int usb4_port_hw_margin(struct tb_port *port, unsigned int lanes,
 			unsigned int ber_level, bool timing, bool right_high,
 			u32 *results);
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index c14a1c3bc992..87e4795275fe 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -346,10 +346,14 @@ struct tb_regs_port_header {
 #define LANE_ADP_CS_1				0x01
 #define LANE_ADP_CS_1_TARGET_SPEED_MASK		GENMASK(3, 0)
 #define LANE_ADP_CS_1_TARGET_SPEED_GEN3		0xc
-#define LANE_ADP_CS_1_TARGET_WIDTH_MASK		GENMASK(9, 4)
+#define LANE_ADP_CS_1_TARGET_WIDTH_MASK		GENMASK(5, 4)
 #define LANE_ADP_CS_1_TARGET_WIDTH_SHIFT	4
 #define LANE_ADP_CS_1_TARGET_WIDTH_SINGLE	0x1
 #define LANE_ADP_CS_1_TARGET_WIDTH_DUAL		0x3
+#define LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK	GENMASK(7, 6)
+#define LANE_ADP_CS_1_TARGET_WIDTH_ASYM_TX	0x1
+#define LANE_ADP_CS_1_TARGET_WIDTH_ASYM_RX	0x2
+#define LANE_ADP_CS_1_TARGET_WIDTH_ASYM_DUAL	0x0
 #define LANE_ADP_CS_1_CL0S_ENABLE		BIT(10)
 #define LANE_ADP_CS_1_CL1_ENABLE		BIT(11)
 #define LANE_ADP_CS_1_CL2_ENABLE		BIT(12)
@@ -382,12 +386,15 @@ struct tb_regs_port_header {
 #define PORT_CS_18_WOCS				BIT(16)
 #define PORT_CS_18_WODS				BIT(17)
 #define PORT_CS_18_WOU4S			BIT(18)
+#define PORT_CS_18_CSA				BIT(22)
+#define PORT_CS_18_TIP				BIT(24)
 #define PORT_CS_19				0x13
 #define PORT_CS_19_PC				BIT(3)
 #define PORT_CS_19_PID				BIT(4)
 #define PORT_CS_19_WOC				BIT(16)
 #define PORT_CS_19_WOD				BIT(17)
 #define PORT_CS_19_WOU4				BIT(18)
+#define PORT_CS_19_START_ASYM			BIT(24)
 
 /* Display Port adapter registers */
 #define ADP_DP_CS_0				0x00
diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 86d6b7b5471b..4277733d0021 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -1454,6 +1454,112 @@ bool usb4_port_clx_supported(struct tb_port *port)
 	return !!(val & PORT_CS_18_CPS);
 }
 
+/**
+ * usb4_port_asym_supported() - If the port supports asymmetric link
+ * @port: USB4 port
+ *
+ * Checks if the port and the cable supports asymmetric link and returns
+ * %true in that case.
+ */
+bool usb4_port_asym_supported(struct tb_port *port)
+{
+	u32 val;
+
+	if (!port->cap_usb4)
+		return false;
+
+	if (tb_port_read(port, &val, TB_CFG_PORT, port->cap_usb4 + PORT_CS_18, 1))
+		return false;
+
+	return !!(val & PORT_CS_18_CSA);
+}
+
+/**
+ * usb4_port_asym_set_link_width() - Set link width to asymmetric or symmetric
+ * @port: USB4 port
+ * @width: Asymmetric width to configure
+ *
+ * Sets USB4 port link width to @width. Can be called for widths where
+ * usb4_port_asym_width_supported() returned @true.
+ */
+int usb4_port_asym_set_link_width(struct tb_port *port, enum tb_link_width width)
+{
+	u32 val;
+	int ret;
+
+	if (!port->cap_phy)
+		return -EINVAL;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_phy + LANE_ADP_CS_1, 1);
+	if (ret)
+		return ret;
+
+	val &= ~LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK;
+	switch (width) {
+	case TB_LINK_WIDTH_DUAL:
+		val |= FIELD_PREP(LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK,
+				  LANE_ADP_CS_1_TARGET_WIDTH_ASYM_DUAL);
+		break;
+	case TB_LINK_WIDTH_ASYM_TX:
+		val |= FIELD_PREP(LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK,
+				  LANE_ADP_CS_1_TARGET_WIDTH_ASYM_TX);
+		break;
+	case TB_LINK_WIDTH_ASYM_RX:
+		val |= FIELD_PREP(LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK,
+				  LANE_ADP_CS_1_TARGET_WIDTH_ASYM_RX);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return tb_port_write(port, &val, TB_CFG_PORT,
+			     port->cap_phy + LANE_ADP_CS_1, 1);
+}
+
+/**
+ * usb4_port_asym_start() - Start symmetry change and wait for completion
+ * @port: USB4 port
+ *
+ * Start symmetry change of the link to asymmetric or symmetric
+ * (according to what was previously set in tb_port_set_link_width().
+ * Wait for completion of the change.
+ *
+ * Returns %0 in case of success, %-ETIMEDOUT if case of timeout or
+ * a negative errno in case of a failure.
+ */
+int usb4_port_asym_start(struct tb_port *port)
+{
+	int ret;
+	u32 val;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_usb4 + PORT_CS_19, 1);
+	if (ret)
+		return ret;
+
+	val &= ~PORT_CS_19_START_ASYM;
+	val |= FIELD_PREP(PORT_CS_19_START_ASYM, 1);
+
+	ret = tb_port_write(port, &val, TB_CFG_PORT,
+			    port->cap_usb4 + PORT_CS_19, 1);
+	if (ret)
+		return ret;
+
+	/*
+	 * Wait for PORT_CS_19_START_ASYM to be 0. This means the USB4
+	 * port started the symmetry transition.
+	 */
+	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_19,
+				     PORT_CS_19_START_ASYM, 0, 1000);
+	if (ret)
+		return ret;
+
+	/* Then wait for the transtion to be completed */
+	return usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_18,
+				      PORT_CS_18_TIP, 0, 5000);
+}
+
 /**
  * usb4_port_margining_caps() - Read USB4 port marginig capabilities
  * @port: USB4 port
