Merge tag 'thunderbolt-for-v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into usb-next

Mika writes:

thunderbolt: Changes for v5.19 merge window

This includes following Thunderbolt/USB4 changes for the v5.19 merge
window:

  * Improvements for Thunderbolt 1 DisplayPort tunneling
  * Link USB4 ports to their USB Type-C connectors
  * Lane bonding support for host-to-host (XDomain) connections
  * Buffer allocation improvement for devices with no DisplayPort
    adapters
  * Few cleanups and minor fixes.

All these have been in linux-next with no reported issues except that
there is a minor merge conflict with the kunit-next tree because one of
the commits touches the driver KUnit tests.

* tag 'thunderbolt-for-v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt:
  thunderbolt: Add KUnit test for devices with no DisplayPort adapters
  thunderbolt: Fix buffer allocation of devices with no DisplayPort adapters
  thunderbolt: Add support for XDomain lane bonding
  thunderbolt: Ignore port locked error in tb_port_wait_for_link_width()
  thunderbolt: Split setting link width and lane bonding into own functions
  thunderbolt: Move tb_port_state() prototype to correct place
  thunderbolt: Add debug logging when lane is enabled/disabled
  thunderbolt: Link USB4 ports to their USB Type-C connectors
  misc/mei: Add NULL check to component match callback functions
  thunderbolt: Use different lane for second DisplayPort tunnel
  thunderbolt: Dump path config space entries during discovery
  thunderbolt: Use decimal number with port numbers
  thunderbolt: Fix typo in comment
  thunderbolt: Replace usage of found with dedicated list iterator variable

17 files changed, 883 insertions, 134 deletions

diff --git a/Documentation/ABI/testing/sysfs-bus-thunderbolt b/Documentation/ABI/testing/sysfs-bus-thunderbolt
index b7e87f6c7d47..f7570c240ce8 100644
--- a/Documentation/ABI/testing/sysfs-bus-thunderbolt
+++ b/Documentation/ABI/testing/sysfs-bus-thunderbolt
@@ -293,6 +293,16 @@ Contact:	thunderbolt-software@lists.01.org
 Description:	This contains XDomain service specific settings as
 		bitmask. Format: %x
 
+What:		/sys/bus/thunderbolt/devices/usb4_portX/connector
+Date:		April 2022
+Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
+Description:
+		Symlink to the USB Type-C connector. This link is only
+		created when USB Type-C Connector Class is enabled,
+		and only if the system firmware is capable of
+		describing the connection between a port and its
+		connector.
+
 What:		/sys/bus/thunderbolt/devices/usb4_portX/link
 Date:		Sep 2021
 KernelVersion:	v5.14
diff --git a/drivers/misc/mei/hdcp/mei_hdcp.c b/drivers/misc/mei/hdcp/mei_hdcp.c
index ec2a4fce8581..e889a8bd7ac8 100644
--- a/drivers/misc/mei/hdcp/mei_hdcp.c
+++ b/drivers/misc/mei/hdcp/mei_hdcp.c
@@ -784,7 +784,7 @@ static int mei_hdcp_component_match(struct device *dev, int subcomponent,
 {
 	struct device *base = data;
 
-	if (strcmp(dev->driver->name, "i915") ||
+	if (!dev->driver || strcmp(dev->driver->name, "i915") ||
 	    subcomponent != I915_COMPONENT_HDCP)
 		return 0;
 
diff --git a/drivers/misc/mei/pxp/mei_pxp.c b/drivers/misc/mei/pxp/mei_pxp.c
index f7380d387bab..5c39457e3f53 100644
--- a/drivers/misc/mei/pxp/mei_pxp.c
+++ b/drivers/misc/mei/pxp/mei_pxp.c
@@ -131,7 +131,7 @@ static int mei_pxp_component_match(struct device *dev, int subcomponent,
 {
 	struct device *base = data;
 
-	if (strcmp(dev->driver->name, "i915") ||
+	if (!dev->driver || strcmp(dev->driver->name, "i915") ||
 	    subcomponent != I915_COMPONENT_PXP)
 		return 0;
 
diff --git a/drivers/thunderbolt/ctl.c b/drivers/thunderbolt/ctl.c
index 4986edfbdf67..e92c658dba1c 100644
--- a/drivers/thunderbolt/ctl.c
+++ b/drivers/thunderbolt/ctl.c
@@ -158,21 +158,20 @@ static bool tb_cfg_request_is_active(struct tb_cfg_request *req)
 static struct tb_cfg_request *
 tb_cfg_request_find(struct tb_ctl *ctl, struct ctl_pkg *pkg)
 {
-	struct tb_cfg_request *req;
-	bool found = false;
+	struct tb_cfg_request *req = NULL, *iter;
 
 	mutex_lock(&pkg->ctl->request_queue_lock);
-	list_for_each_entry(req, &pkg->ctl->request_queue, list) {
-		tb_cfg_request_get(req);
-		if (req->match(req, pkg)) {
-			found = true;
+	list_for_each_entry(iter, &pkg->ctl->request_queue, list) {
+		tb_cfg_request_get(iter);
+		if (iter->match(iter, pkg)) {
+			req = iter;
 			break;
 		}
-		tb_cfg_request_put(req);
+		tb_cfg_request_put(iter);
 	}
 	mutex_unlock(&pkg->ctl->request_queue_lock);
 
-	return found ? req : NULL;
+	return req;
 }
 
 /* utility functions */
diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index 4a582183f675..6221ca4ea287 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -1207,7 +1207,7 @@ static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	nhi->pdev = pdev;
 	nhi->ops = (const struct tb_nhi_ops *)id->driver_data;
-	/* cannot fail - table is allocated bin pcim_iomap_regions */
+	/* cannot fail - table is allocated in pcim_iomap_regions */
 	nhi->iobase = pcim_iomap_table(pdev)[0];
 	nhi->hop_count = ioread32(nhi->iobase + REG_HOP_COUNT) & 0x3ff;
 	dev_dbg(&pdev->dev, "total paths: %d\n", nhi->hop_count);
diff --git a/drivers/thunderbolt/path.c b/drivers/thunderbolt/path.c
index 299712accfe9..ee03fd75a472 100644
--- a/drivers/thunderbolt/path.c
+++ b/drivers/thunderbolt/path.c
@@ -166,6 +166,9 @@ struct tb_path *tb_path_discover(struct tb_port *src, int src_hopid,
 		return NULL;
 	}
 
+	tb_dbg(path->tb, "discovering %s path starting from %llx:%u\n",
+	       path->name, tb_route(src->sw), src->port);
+
 	p = src;
 	h = src_hopid;
 
@@ -198,10 +201,13 @@ struct tb_path *tb_path_discover(struct tb_port *src, int src_hopid,
 		path->hops[i].out_port = out_port;
 		path->hops[i].next_hop_index = next_hop;
 
+		tb_dump_hop(&path->hops[i], &hop);
+
 		h = next_hop;
 		p = out_port->remote;
 	}
 
+	tb_dbg(path->tb, "path discovery complete\n");
 	return path;
 
 err:
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index ac87e8b50e52..561e1d77240e 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -693,8 +693,14 @@ static int __tb_port_enable(struct tb_port *port, bool enable)
 	else
 		phy |= LANE_ADP_CS_1_LD;
 
-	return tb_port_write(port, &phy, TB_CFG_PORT,
-			     port->cap_phy + LANE_ADP_CS_1, 1);
+
+	ret = tb_port_write(port, &phy, TB_CFG_PORT,
+			    port->cap_phy + LANE_ADP_CS_1, 1);
+	if (ret)
+		return ret;
+
+	tb_port_dbg(port, "lane %sabled\n", enable ? "en" : "dis");
+	return 0;
 }
 
 /**
@@ -993,7 +999,17 @@ static bool tb_port_is_width_supported(struct tb_port *port, int width)
 	return !!(widths & width);
 }
 
-static int tb_port_set_link_width(struct tb_port *port, unsigned int width)
+/**
+ * tb_port_set_link_width() - Set target link width of the lane adapter
+ * @port: Lane adapter
+ * @width: Target link width (%1 or %2)
+ *
+ * Sets the target link width of the lane adapter to @width. Does not
+ * enable/disable lane bonding. For that call tb_port_set_lane_bonding().
+ *
+ * Return: %0 in case of success and negative errno in case of error
+ */
+int tb_port_set_link_width(struct tb_port *port, unsigned int width)
 {
 	u32 val;
 	int ret;
@@ -1020,13 +1036,59 @@ static int tb_port_set_link_width(struct tb_port *port, unsigned int width)
 		return -EINVAL;
 	}
 
-	val |= LANE_ADP_CS_1_LB;
-
 	return tb_port_write(port, &val, TB_CFG_PORT,
 			     port->cap_phy + LANE_ADP_CS_1, 1);
 }
 
 /**
+ * tb_port_set_lane_bonding() - Enable/disable lane bonding
+ * @port: Lane adapter
+ * @bonding: enable/disable bonding
+ *
+ * Enables or disables lane bonding. This should be called after target
+ * link width has been set (tb_port_set_link_width()). Note in most
+ * cases one should use tb_port_lane_bonding_enable() instead to enable
+ * lane bonding.
+ *
+ * As a side effect sets @port->bonding accordingly (and does the same
+ * for lane 1 too).
+ *
+ * Return: %0 in case of success and negative errno in case of error
+ */
+int tb_port_set_lane_bonding(struct tb_port *port, bool bonding)
+{
+	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;
+
+	if (bonding)
+		val |= LANE_ADP_CS_1_LB;
+	else
+		val &= ~LANE_ADP_CS_1_LB;
+
+	ret = tb_port_write(port, &val, TB_CFG_PORT,
+			    port->cap_phy + LANE_ADP_CS_1, 1);
+	if (ret)
+		return ret;
+
+	/*
+	 * When lane 0 bonding is set it will affect lane 1 too so
+	 * update both.
+	 */
+	port->bonded = bonding;
+	port->dual_link_port->bonded = bonding;
+
+	return 0;
+}
+
+/**
  * tb_port_lane_bonding_enable() - Enable bonding on port
  * @port: port to enable
  *
@@ -1050,22 +1112,27 @@ int tb_port_lane_bonding_enable(struct tb_port *port)
 	if (ret == 1) {
 		ret = tb_port_set_link_width(port, 2);
 		if (ret)
-			return ret;
+			goto err_lane0;
 	}
 
 	ret = tb_port_get_link_width(port->dual_link_port);
 	if (ret == 1) {
 		ret = tb_port_set_link_width(port->dual_link_port, 2);
-		if (ret) {
-			tb_port_set_link_width(port, 1);
-			return ret;
-		}
+		if (ret)
+			goto err_lane0;
 	}
 
-	port->bonded = true;
-	port->dual_link_port->bonded = true;
+	ret = tb_port_set_lane_bonding(port, true);
+	if (ret)
+		goto err_lane1;
 
 	return 0;
+
+err_lane1:
+	tb_port_set_link_width(port->dual_link_port, 1);
+err_lane0:
+	tb_port_set_link_width(port, 1);
+	return ret;
 }
 
 /**
@@ -1074,13 +1141,10 @@ int tb_port_lane_bonding_enable(struct tb_port *port)
  *
  * Disable bonding by setting the link width of the port and the
  * other port in case of dual link port.
- *
  */
 void tb_port_lane_bonding_disable(struct tb_port *port)
 {
-	port->dual_link_port->bonded = false;
-	port->bonded = false;
-
+	tb_port_set_lane_bonding(port, false);
 	tb_port_set_link_width(port->dual_link_port, 1);
 	tb_port_set_link_width(port, 1);
 }
@@ -1104,10 +1168,17 @@ int tb_port_wait_for_link_width(struct tb_port *port, int width,
 
 	do {
 		ret = tb_port_get_link_width(port);
-		if (ret < 0)
-			return ret;
-		else if (ret == width)
+		if (ret < 0) {
+			/*
+			 * Sometimes we get port locked error when
+			 * polling the lanes so we can ignore it and
+			 * retry.
+			 */
+			if (ret != -EACCES)
+				return ret;
+		} else if (ret == width) {
 			return 0;
+		}
 
 		usleep_range(1000, 2000);
 	} while (ktime_before(ktime_get(), timeout));
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 9beb47b31c75..9a3214fb5038 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -169,12 +169,6 @@ static void tb_discover_tunnels(struct tb *tb)
 
 static int tb_port_configure_xdomain(struct tb_port *port)
 {
-	/*
-	 * XDomain paths currently only support single lane so we must
-	 * disable the other lane according to USB4 spec.
-	 */
-	tb_port_disable(port->dual_link_port);
-
 	if (tb_switch_is_usb4(port->sw))
 		return usb4_port_configure_xdomain(port);
 	return tb_lc_configure_xdomain(port);
@@ -867,7 +861,7 @@ static struct tb_port *tb_find_dp_out(struct tb *tb, struct tb_port *in)
 
 static void tb_tunnel_dp(struct tb *tb)
 {
-	int available_up, available_down, ret;
+	int available_up, available_down, ret, link_nr;
 	struct tb_cm *tcm = tb_priv(tb);
 	struct tb_port *port, *in, *out;
 	struct tb_tunnel *tunnel;
@@ -913,6 +907,20 @@ static void tb_tunnel_dp(struct tb *tb)
 	}
 
 	/*
+	 * This is only applicable to links that are not bonded (so
+	 * when Thunderbolt 1 hardware is involved somewhere in the
+	 * topology). For these try to share the DP bandwidth between
+	 * the two lanes.
+	 */
+	link_nr = 1;
+	list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
+		if (tb_tunnel_is_dp(tunnel)) {
+			link_nr = 0;
+			break;
+		}
+	}
+
+	/*
 	 * DP stream needs the domain to be active so runtime resume
 	 * both ends of the tunnel.
 	 *
@@ -943,7 +951,8 @@ static void tb_tunnel_dp(struct tb *tb)
 	tb_dbg(tb, "available bandwidth for new DP tunnel %u/%u Mb/s\n",
 	       available_up, available_down);
 
-	tunnel = tb_tunnel_alloc_dp(tb, in, out, available_up, available_down);
+	tunnel = tb_tunnel_alloc_dp(tb, in, out, link_nr, available_up,
+				    available_down);
 	if (!tunnel) {
 		tb_port_dbg(out, "could not allocate DP tunnel\n");
 		goto err_reclaim;
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index b6fcd8d45324..4602c69913fa 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -674,7 +674,7 @@ static inline int tb_port_write(struct tb_port *port, const void *buffer,
 #define __TB_PORT_PRINT(level, _port, fmt, arg...)                      \
 	do {                                                            \
 		const struct tb_port *__port = (_port);                 \
-		level(__port->sw->tb, "%llx:%x: " fmt,                  \
+		level(__port->sw->tb, "%llx:%u: " fmt,                  \
 		      tb_route(__port->sw), __port->port, ## arg);      \
 	} while (0)
 #define tb_port_WARN(port, fmt, arg...) \
@@ -991,6 +991,7 @@ int tb_switch_pcie_l1_enable(struct tb_switch *sw);
 int tb_switch_xhci_connect(struct tb_switch *sw);
 void tb_switch_xhci_disconnect(struct tb_switch *sw);
 
+int tb_port_state(struct tb_port *port);
 int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged);
 int tb_port_add_nfc_credits(struct tb_port *port, int credits);
 int tb_port_clear_counter(struct tb_port *port, int counter);
@@ -1023,7 +1024,8 @@ 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_width(struct tb_port *port);
-int tb_port_state(struct tb_port *port);
+int tb_port_set_link_width(struct tb_port *port, unsigned int width);
+int tb_port_set_lane_bonding(struct tb_port *port, bool bonding);
 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, int width,
diff --git a/drivers/thunderbolt/tb_msgs.h b/drivers/thunderbolt/tb_msgs.h
index fe1afa44c56d..33c4c7aed56d 100644
--- a/drivers/thunderbolt/tb_msgs.h
+++ b/drivers/thunderbolt/tb_msgs.h
@@ -527,6 +527,10 @@ enum tb_xdp_type {
 	PROPERTIES_CHANGED_RESPONSE,
 	ERROR_RESPONSE,
 	UUID_REQUEST = 12,
+	LINK_STATE_STATUS_REQUEST = 15,
+	LINK_STATE_STATUS_RESPONSE,
+	LINK_STATE_CHANGE_REQUEST,
+	LINK_STATE_CHANGE_RESPONSE,
 };
 
 struct tb_xdp_header {
@@ -540,6 +544,41 @@ struct tb_xdp_error_response {
 	u32 error;
 };
 
+struct tb_xdp_link_state_status {
+	struct tb_xdp_header hdr;
+};
+
+struct tb_xdp_link_state_status_response {
+	union {
+		struct tb_xdp_error_response err;
+		struct {
+			struct tb_xdp_header hdr;
+			u32 status;
+			u8 slw;
+			u8 tlw;
+			u8 sls;
+			u8 tls;
+		};
+	};
+};
+
+struct tb_xdp_link_state_change {
+	struct tb_xdp_header hdr;
+	u8 tlw;
+	u8 tls;
+	u16 reserved;
+};
+
+struct tb_xdp_link_state_change_response {
+	union {
+		struct tb_xdp_error_response err;
+		struct {
+			struct tb_xdp_header hdr;
+			u32 status;
+		};
+	};
+};
+
 struct tb_xdp_uuid {
 	struct tb_xdp_header hdr;
 };
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index b301eeb0c89b..6a16f61a72a1 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -311,11 +311,16 @@ struct tb_regs_port_header {
 
 /* Lane adapter registers */
 #define LANE_ADP_CS_0				0x00
+#define LANE_ADP_CS_0_SUPPORTED_SPEED_MASK	GENMASK(19, 16)
+#define LANE_ADP_CS_0_SUPPORTED_SPEED_SHIFT	16
 #define LANE_ADP_CS_0_SUPPORTED_WIDTH_MASK	GENMASK(25, 20)
 #define LANE_ADP_CS_0_SUPPORTED_WIDTH_SHIFT	20
+#define LANE_ADP_CS_0_SUPPORTED_WIDTH_DUAL	0x2
 #define LANE_ADP_CS_0_CL0S_SUPPORT		BIT(26)
 #define LANE_ADP_CS_0_CL1_SUPPORT		BIT(27)
 #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_SHIFT	4
 #define LANE_ADP_CS_1_TARGET_WIDTH_SINGLE	0x1
diff --git a/drivers/thunderbolt/test.c b/drivers/thunderbolt/test.c
index 1f69bab236ee..99b30f2624fc 100644
--- a/drivers/thunderbolt/test.c
+++ b/drivers/thunderbolt/test.c
@@ -341,6 +341,47 @@ static struct tb_switch *alloc_dev_with_dpin(struct kunit *test,
 	return sw;
 }
 
+static struct tb_switch *alloc_dev_without_dp(struct kunit *test,
+					      struct tb_switch *parent,
+					      u64 route, bool bonded)
+{
+	struct tb_switch *sw;
+	int i;
+
+	sw = alloc_dev_default(test, parent, route, bonded);
+	if (!sw)
+		return NULL;
+	/*
+	 * Device with:
+	 * 2x USB4 Adapters (adapters 1,2 and 3,4),
+	 * 1x PCIe Upstream (adapter 9),
+	 * 1x PCIe Downstream (adapter 10),
+	 * 1x USB3 Upstream (adapter 16),
+	 * 1x USB3 Downstream (adapter 17)
+	 */
+	for (i = 5; i <= 8; i++)
+		sw->ports[i].disabled = true;
+
+	for (i = 11; i <= 14; i++)
+		sw->ports[i].disabled = true;
+
+	sw->ports[13].cap_adap = 0;
+	sw->ports[14].cap_adap = 0;
+
+	for (i = 18; i <= 19; i++)
+		sw->ports[i].disabled = true;
+
+	sw->generation = 4;
+	sw->credit_allocation = true;
+	sw->max_usb3_credits = 109;
+	sw->min_dp_aux_credits = 0;
+	sw->min_dp_main_credits = 0;
+	sw->max_pcie_credits = 30;
+	sw->max_dma_credits = 1;
+
+	return sw;
+}
+
 static struct tb_switch *alloc_dev_usb4(struct kunit *test,
 					struct tb_switch *parent,
 					u64 route, bool bonded)
@@ -1348,7 +1389,7 @@ static void tb_test_tunnel_dp(struct kunit *test)
 	in = &host->ports[5];
 	out = &dev->ports[13];
 
-	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0);
+	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0);
 	KUNIT_ASSERT_TRUE(test, tunnel != NULL);
 	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP);
 	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in);
@@ -1394,7 +1435,7 @@ static void tb_test_tunnel_dp_chain(struct kunit *test)
 	in = &host->ports[5];
 	out = &dev4->ports[14];
 
-	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0);
+	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0);
 	KUNIT_ASSERT_TRUE(test, tunnel != NULL);
 	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP);
 	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in);
@@ -1444,7 +1485,7 @@ static void tb_test_tunnel_dp_tree(struct kunit *test)
 	in = &dev2->ports[13];
 	out = &dev5->ports[13];
 
-	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0);
+	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0);
 	KUNIT_ASSERT_TRUE(test, tunnel != NULL);
 	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP);
 	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in);
@@ -1509,7 +1550,7 @@ static void tb_test_tunnel_dp_max_length(struct kunit *test)
 	in = &dev6->ports[13];
 	out = &dev12->ports[13];
 
-	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0);
+	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0);
 	KUNIT_ASSERT_TRUE(test, tunnel != NULL);
 	KUNIT_EXPECT_EQ(test, tunnel->type, TB_TUNNEL_DP);
 	KUNIT_EXPECT_PTR_EQ(test, tunnel->src_port, in);
@@ -1627,7 +1668,7 @@ static void tb_test_tunnel_port_on_path(struct kunit *test)
 	in = &dev2->ports[13];
 	out = &dev5->ports[13];
 
-	dp_tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0);
+	dp_tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0);
 	KUNIT_ASSERT_TRUE(test, dp_tunnel != NULL);
 
 	KUNIT_EXPECT_TRUE(test, tb_tunnel_port_on_path(dp_tunnel, in));
@@ -1996,6 +2037,56 @@ static void tb_test_credit_alloc_pcie(struct kunit *test)
 	tb_tunnel_free(tunnel);
 }
 
+static void tb_test_credit_alloc_without_dp(struct kunit *test)
+{
+	struct tb_switch *host, *dev;
+	struct tb_port *up, *down;
+	struct tb_tunnel *tunnel;
+	struct tb_path *path;
+
+	host = alloc_host_usb4(test);
+	dev = alloc_dev_without_dp(test, host, 0x1, true);
+
+	/*
+	 * The device has no DP therefore baMinDPmain = baMinDPaux = 0
+	 *
+	 * Create PCIe path with buffers less than baMaxPCIe.
+	 *
+	 * For a device with buffers configurations:
+	 * baMaxUSB3 = 109
+	 * baMinDPaux = 0
+	 * baMinDPmain = 0
+	 * baMaxPCIe = 30
+	 * baMaxHI = 1
+	 * Remaining Buffers = Total - (CP + DP) = 120 - (2 + 0) = 118
+	 * PCIe Credits = Max(6, Min(baMaxPCIe, Remaining Buffers - baMaxUSB3)
+	 *		= Max(6, Min(30, 9) = 9
+	 */
+	down = &host->ports[8];
+	up = &dev->ports[9];
+	tunnel = tb_tunnel_alloc_pci(NULL, up, down);
+	KUNIT_ASSERT_TRUE(test, tunnel != NULL);
+	KUNIT_ASSERT_EQ(test, tunnel->npaths, (size_t)2);
+
+	/* PCIe downstream path */
+	path = tunnel->paths[0];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 9U);
+
+	/* PCIe upstream path */
+	path = tunnel->paths[1];
+	KUNIT_ASSERT_EQ(test, path->path_length, 2);
+	KUNIT_EXPECT_EQ(test, path->hops[0].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[0].initial_credits, 7U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].nfc_credits, 0U);
+	KUNIT_EXPECT_EQ(test, path->hops[1].initial_credits, 64U);
+
+	tb_tunnel_free(tunnel);
+}
+
 static void tb_test_credit_alloc_dp(struct kunit *test)
 {
 	struct tb_switch *host, *dev;
@@ -2009,7 +2100,7 @@ static void tb_test_credit_alloc_dp(struct kunit *test)
 	in = &host->ports[5];
 	out = &dev->ports[14];
 
-	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 0, 0);
+	tunnel = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0);
 	KUNIT_ASSERT_TRUE(test, tunnel != NULL);
 	KUNIT_ASSERT_EQ(test, tunnel->npaths, (size_t)3);
 
@@ -2245,7 +2336,7 @@ static struct tb_tunnel *TB_TEST_DP_TUNNEL1(struct kunit *test,
 
 	in = &host->ports[5];
 	out = &dev->ports[13];
-	dp_tunnel1 = tb_tunnel_alloc_dp(NULL, in, out, 0, 0);
+	dp_tunnel1 = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0);
 	KUNIT_ASSERT_TRUE(test, dp_tunnel1 != NULL);
 	KUNIT_ASSERT_EQ(test, dp_tunnel1->npaths, (size_t)3);
 
@@ -2282,7 +2373,7 @@ static struct tb_tunnel *TB_TEST_DP_TUNNEL2(struct kunit *test,
 
 	in = &host->ports[6];
 	out = &dev->ports[14];
-	dp_tunnel2 = tb_tunnel_alloc_dp(NULL, in, out, 0, 0);
+	dp_tunnel2 = tb_tunnel_alloc_dp(NULL, in, out, 1, 0, 0);
 	KUNIT_ASSERT_TRUE(test, dp_tunnel2 != NULL);
 	KUNIT_ASSERT_EQ(test, dp_tunnel2->npaths, (size_t)3);
 
@@ -2709,6 +2800,7 @@ static struct kunit_case tb_test_cases[] = {
 	KUNIT_CASE(tb_test_credit_alloc_legacy_not_bonded),
 	KUNIT_CASE(tb_test_credit_alloc_legacy_bonded),
 	KUNIT_CASE(tb_test_credit_alloc_pcie),
+	KUNIT_CASE(tb_test_credit_alloc_without_dp),
 	KUNIT_CASE(tb_test_credit_alloc_dp),
 	KUNIT_CASE(tb_test_credit_alloc_usb3),
 	KUNIT_CASE(tb_test_credit_alloc_dma),
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index 118742ec93ed..2c3cf7fc3357 100644
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -102,8 +102,11 @@ static unsigned int tb_available_credits(const struct tb_port *port,
 		 * Maximum number of DP streams possible through the
 		 * lane adapter.
 		 */
-		ndp = (credits - (usb3 + pcie + spare)) /
-		      (sw->min_dp_aux_credits + sw->min_dp_main_credits);
+		if (sw->min_dp_aux_credits + sw->min_dp_main_credits)
+			ndp = (credits - (usb3 + pcie + spare)) /
+			      (sw->min_dp_aux_credits + sw->min_dp_main_credits);
+		else
+			ndp = 0;
 	} else {
 		ndp = 0;
 	}
@@ -858,6 +861,7 @@ err_free:
  * @tb: Pointer to the domain structure
  * @in: DP in adapter port
  * @out: DP out adapter port
+ * @link_nr: Preferred lane adapter when the link is not bonded
  * @max_up: Maximum available upstream bandwidth for the DP tunnel (%0
  *	    if not limited)
  * @max_down: Maximum available downstream bandwidth for the DP tunnel
@@ -869,8 +873,8 @@ err_free:
  * Return: Returns a tb_tunnel on success or NULL on failure.
  */
 struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
-				     struct tb_port *out, int max_up,
-				     int max_down)
+				     struct tb_port *out, int link_nr,
+				     int max_up, int max_down)
 {
 	struct tb_tunnel *tunnel;
 	struct tb_path **paths;
@@ -894,21 +898,21 @@ struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
 	paths = tunnel->paths;
 
 	path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
-			     1, "Video");
+			     link_nr, "Video");
 	if (!path)
 		goto err_free;
 	tb_dp_init_video_path(path);
 	paths[TB_DP_VIDEO_PATH_OUT] = path;
 
 	path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
-			     TB_DP_AUX_TX_HOPID, 1, "AUX TX");
+			     TB_DP_AUX_TX_HOPID, link_nr, "AUX TX");
 	if (!path)
 		goto err_free;
 	tb_dp_init_aux_path(path);
 	paths[TB_DP_AUX_PATH_OUT] = path;
 
 	path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
-			     TB_DP_AUX_RX_HOPID, 1, "AUX RX");
+			     TB_DP_AUX_RX_HOPID, link_nr, "AUX RX");
 	if (!path)
 		goto err_free;
 	tb_dp_init_aux_path(path);
diff --git a/drivers/thunderbolt/tunnel.h b/drivers/thunderbolt/tunnel.h
index 03e56076b5bc..bb4d1f1d6d0b 100644
--- a/drivers/thunderbolt/tunnel.h
+++ b/drivers/thunderbolt/tunnel.h
@@ -71,8 +71,8 @@ struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
 struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in,
 					bool alloc_hopid);
 struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
-				     struct tb_port *out, int max_up,
-				     int max_down);
+				     struct tb_port *out, int link_nr,
+				     int max_up, int max_down);
 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
 				      struct tb_port *dst, int transmit_path,
 				      int transmit_ring, int receive_path,
diff --git a/drivers/thunderbolt/usb4_port.c b/drivers/thunderbolt/usb4_port.c
index 29e2a4f9c9f5..6b02945624ee 100644
--- a/drivers/thunderbolt/usb4_port.c
+++ b/drivers/thunderbolt/usb4_port.c
@@ -7,9 +7,37 @@
  */
 
 #include <linux/pm_runtime.h>
+#include <linux/component.h>
+#include <linux/property.h>
 
 #include "tb.h"
 
+static int connector_bind(struct device *dev, struct device *connector, void *data)
+{
+	int ret;
+
+	ret = sysfs_create_link(&dev->kobj, &connector->kobj, "connector");
+	if (ret)
+		return ret;
+
+	ret = sysfs_create_link(&connector->kobj, &dev->kobj, dev_name(dev));
+	if (ret)
+		sysfs_remove_link(&dev->kobj, "connector");
+
+	return ret;
+}
+
+static void connector_unbind(struct device *dev, struct device *connector, void *data)
+{
+	sysfs_remove_link(&connector->kobj, dev_name(dev));
+	sysfs_remove_link(&dev->kobj, "connector");
+}
+
+static const struct component_ops connector_ops = {
+	.bind = connector_bind,
+	.unbind = connector_unbind,
+};
+
 static ssize_t link_show(struct device *dev, struct device_attribute *attr,
 			 char *buf)
 {
@@ -246,6 +274,14 @@ struct usb4_port *usb4_port_device_add(struct tb_port *port)
 		return ERR_PTR(ret);
 	}
 
+	if (dev_fwnode(&usb4->dev)) {
+		ret = component_add(&usb4->dev, &connector_ops);
+		if (ret) {
+			dev_err(&usb4->dev, "failed to add component\n");
+			device_unregister(&usb4->dev);
+		}
+	}
+
 	pm_runtime_no_callbacks(&usb4->dev);
 	pm_runtime_set_active(&usb4->dev);
 	pm_runtime_enable(&usb4->dev);
@@ -265,6 +301,8 @@ struct usb4_port *usb4_port_device_add(struct tb_port *port)
  */
 void usb4_port_device_remove(struct usb4_port *usb4)
 {
+	if (dev_fwnode(&usb4->dev))
+		component_del(&usb4->dev, &connector_ops);
 	device_unregister(&usb4->dev);
 }
 
diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
index 01d6b724ca51..c31c0d94d8b3 100644
--- a/drivers/thunderbolt/xdomain.c
+++ b/drivers/thunderbolt/xdomain.c
@@ -19,13 +19,38 @@
 
 #include "tb.h"
 
-#define XDOMAIN_DEFAULT_TIMEOUT			1000 /* ms */
-#define XDOMAIN_UUID_RETRIES			10
-#define XDOMAIN_PROPERTIES_RETRIES		10
-#define XDOMAIN_PROPERTIES_CHANGED_RETRIES	10
-#define XDOMAIN_BONDING_WAIT			100  /* ms */
+#define XDOMAIN_SHORT_TIMEOUT			100	/* ms */
+#define XDOMAIN_DEFAULT_TIMEOUT			1000	/* ms */
+#define XDOMAIN_BONDING_TIMEOUT			10000	/* ms */
+#define XDOMAIN_RETRIES				10
 #define XDOMAIN_DEFAULT_MAX_HOPID		15
 
+enum {
+	XDOMAIN_STATE_INIT,
+	XDOMAIN_STATE_UUID,
+	XDOMAIN_STATE_LINK_STATUS,
+	XDOMAIN_STATE_LINK_STATE_CHANGE,
+	XDOMAIN_STATE_LINK_STATUS2,
+	XDOMAIN_STATE_BONDING_UUID_LOW,
+	XDOMAIN_STATE_BONDING_UUID_HIGH,
+	XDOMAIN_STATE_PROPERTIES,
+	XDOMAIN_STATE_ENUMERATED,
+	XDOMAIN_STATE_ERROR,
+};
+
+static const char * const state_names[] = {
+	[XDOMAIN_STATE_INIT] = "INIT",
+	[XDOMAIN_STATE_UUID] = "UUID",
+	[XDOMAIN_STATE_LINK_STATUS] = "LINK_STATUS",
+	[XDOMAIN_STATE_LINK_STATE_CHANGE] = "LINK_STATE_CHANGE",
+	[XDOMAIN_STATE_LINK_STATUS2] = "LINK_STATUS2",
+	[XDOMAIN_STATE_BONDING_UUID_LOW] = "BONDING_UUID_LOW",
+	[XDOMAIN_STATE_BONDING_UUID_HIGH] = "BONDING_UUID_HIGH",
+	[XDOMAIN_STATE_PROPERTIES] = "PROPERTIES",
+	[XDOMAIN_STATE_ENUMERATED] = "ENUMERATED",
+	[XDOMAIN_STATE_ERROR] = "ERROR",
+};
+
 struct xdomain_request_work {
 	struct work_struct work;
 	struct tb_xdp_header *pkg;
@@ -235,7 +260,7 @@ static int tb_xdp_handle_error(const struct tb_xdp_error_response *res)
 }
 
 static int tb_xdp_uuid_request(struct tb_ctl *ctl, u64 route, int retry,
-			       uuid_t *uuid)
+			       uuid_t *uuid, u64 *remote_route)
 {
 	struct tb_xdp_uuid_response res;
 	struct tb_xdp_uuid req;
@@ -258,6 +283,8 @@ static int tb_xdp_uuid_request(struct tb_ctl *ctl, u64 route, int retry,
 		return ret;
 
 	uuid_copy(uuid, &res.src_uuid);
+	*remote_route = (u64)res.src_route_hi << 32 | res.src_route_lo;
+
 	return 0;
 }
 
@@ -473,6 +500,112 @@ tb_xdp_properties_changed_response(struct tb_ctl *ctl, u64 route, u8 sequence)
 				     TB_CFG_PKG_XDOMAIN_RESP);
 }
 
+static int tb_xdp_link_state_status_request(struct tb_ctl *ctl, u64 route,
+					    u8 sequence, u8 *slw, u8 *tlw,
+					    u8 *sls, u8 *tls)
+{
+	struct tb_xdp_link_state_status_response res;
+	struct tb_xdp_link_state_status req;
+	int ret;
+
+	memset(&req, 0, sizeof(req));
+	tb_xdp_fill_header(&req.hdr, route, sequence, LINK_STATE_STATUS_REQUEST,
+			   sizeof(req));
+
+	memset(&res, 0, sizeof(res));
+	ret = __tb_xdomain_request(ctl, &req, sizeof(req), TB_CFG_PKG_XDOMAIN_REQ,
+				   &res, sizeof(res), TB_CFG_PKG_XDOMAIN_RESP,
+				   XDOMAIN_DEFAULT_TIMEOUT);
+	if (ret)
+		return ret;
+
+	ret = tb_xdp_handle_error(&res.err);
+	if (ret)
+		return ret;
+
+	if (res.status != 0)
+		return -EREMOTEIO;
+
+	*slw = res.slw;
+	*tlw = res.tlw;
+	*sls = res.sls;
+	*tls = res.tls;
+
+	return 0;
+}
+
+static int tb_xdp_link_state_status_response(struct tb *tb, struct tb_ctl *ctl,
+					     struct tb_xdomain *xd, u8 sequence)
+{
+	struct tb_switch *sw = tb_to_switch(xd->dev.parent);
+	struct tb_xdp_link_state_status_response res;
+	struct tb_port *port = tb_port_at(xd->route, sw);
+	u32 val[2];
+	int ret;
+
+	memset(&res, 0, sizeof(res));
+	tb_xdp_fill_header(&res.hdr, xd->route, sequence,
+			   LINK_STATE_STATUS_RESPONSE, sizeof(res));
+
+	ret = tb_port_read(port, val, TB_CFG_PORT,
+			   port->cap_phy + LANE_ADP_CS_0, ARRAY_SIZE(val));
+	if (ret)
+		return ret;
+
+	res.slw = (val[0] & LANE_ADP_CS_0_SUPPORTED_WIDTH_MASK) >>
+			LANE_ADP_CS_0_SUPPORTED_WIDTH_SHIFT;
+	res.sls = (val[0] & LANE_ADP_CS_0_SUPPORTED_SPEED_MASK) >>
+			LANE_ADP_CS_0_SUPPORTED_SPEED_SHIFT;
+	res.tls = val[1] & LANE_ADP_CS_1_TARGET_SPEED_MASK;
+	res.tlw = (val[1] & LANE_ADP_CS_1_TARGET_WIDTH_MASK) >>
+			LANE_ADP_CS_1_TARGET_WIDTH_SHIFT;
+
+	return __tb_xdomain_response(ctl, &res, sizeof(res),
+				     TB_CFG_PKG_XDOMAIN_RESP);
+}
+
+static int tb_xdp_link_state_change_request(struct tb_ctl *ctl, u64 route,
+					    u8 sequence, u8 tlw, u8 tls)
+{
+	struct tb_xdp_link_state_change_response res;
+	struct tb_xdp_link_state_change req;
+	int ret;
+
+	memset(&req, 0, sizeof(req));
+	tb_xdp_fill_header(&req.hdr, route, sequence, LINK_STATE_CHANGE_REQUEST,
+			   sizeof(req));
+	req.tlw = tlw;
+	req.tls = tls;
+
+	memset(&res, 0, sizeof(res));
+	ret = __tb_xdomain_request(ctl, &req, sizeof(req), TB_CFG_PKG_XDOMAIN_REQ,
+				   &res, sizeof(res), TB_CFG_PKG_XDOMAIN_RESP,
+				   XDOMAIN_DEFAULT_TIMEOUT);
+	if (ret)
+		return ret;
+
+	ret = tb_xdp_handle_error(&res.err);
+	if (ret)
+		return ret;
+
+	return res.status != 0 ? -EREMOTEIO : 0;
+}
+
+static int tb_xdp_link_state_change_response(struct tb_ctl *ctl, u64 route,
+					     u8 sequence, u32 status)
+{
+	struct tb_xdp_link_state_change_response res;
+
+	memset(&res, 0, sizeof(res));
+	tb_xdp_fill_header(&res.hdr, route, sequence, LINK_STATE_CHANGE_RESPONSE,
+			   sizeof(res));
+
+	res.status = status;
+
+	return __tb_xdomain_response(ctl, &res, sizeof(res),
+				     TB_CFG_PKG_XDOMAIN_RESP);
+}
+
 /**
  * tb_register_protocol_handler() - Register protocol handler
  * @handler: Handler to register
@@ -600,14 +733,13 @@ static void tb_xdp_handle_request(struct work_struct *work)
 		goto out;
 	}
 
-	tb_dbg(tb, "%llx: received XDomain request %#x\n", route, pkg->type);
-
 	xd = tb_xdomain_find_by_route_locked(tb, route);
 	if (xd)
 		update_property_block(xd);
 
 	switch (pkg->type) {
 	case PROPERTIES_REQUEST:
+		tb_dbg(tb, "%llx: received XDomain properties request\n", route);
 		if (xd) {
 			ret = tb_xdp_properties_response(tb, ctl, xd, sequence,
 				(const struct tb_xdp_properties *)pkg);
@@ -615,6 +747,9 @@ static void tb_xdp_handle_request(struct work_struct *work)
 		break;
 
 	case PROPERTIES_CHANGED_REQUEST:
+		tb_dbg(tb, "%llx: received XDomain properties changed request\n",
+		       route);
+
 		ret = tb_xdp_properties_changed_response(ctl, route, sequence);
 
 		/*
@@ -622,18 +757,51 @@ static void tb_xdp_handle_request(struct work_struct *work)
 		 * the xdomain related to this connection as well in
 		 * case there is a change in services it offers.
 		 */
-		if (xd && device_is_registered(&xd->dev)) {
-			queue_delayed_work(tb->wq, &xd->get_properties_work,
-					   msecs_to_jiffies(50));
-		}
+		if (xd && device_is_registered(&xd->dev))
+			queue_delayed_work(tb->wq, &xd->state_work,
+					   msecs_to_jiffies(XDOMAIN_SHORT_TIMEOUT));
 		break;
 
 	case UUID_REQUEST_OLD:
 	case UUID_REQUEST:
+		tb_dbg(tb, "%llx: received XDomain UUID request\n", route);
 		ret = tb_xdp_uuid_response(ctl, route, sequence, uuid);
 		break;
 
+	case LINK_STATE_STATUS_REQUEST:
+		tb_dbg(tb, "%llx: received XDomain link state status request\n",
+		       route);
+
+		if (xd) {
+			ret = tb_xdp_link_state_status_response(tb, ctl, xd,
+								sequence);
+		} else {
+			tb_xdp_error_response(ctl, route, sequence,
+					      ERROR_NOT_READY);
+		}
+		break;
+
+	case LINK_STATE_CHANGE_REQUEST:
+		tb_dbg(tb, "%llx: received XDomain link state change request\n",
+		       route);
+
+		if (xd && xd->state == XDOMAIN_STATE_BONDING_UUID_HIGH) {
+			const struct tb_xdp_link_state_change *lsc =
+				(const struct tb_xdp_link_state_change *)pkg;
+
+			ret = tb_xdp_link_state_change_response(ctl, route,
+								sequence, 0);
+			xd->target_link_width = lsc->tlw;
+			queue_delayed_work(tb->wq, &xd->state_work,
+					   msecs_to_jiffies(XDOMAIN_SHORT_TIMEOUT));
+		} else {
+			tb_xdp_error_response(ctl, route, sequence,
+					      ERROR_NOT_READY);
+		}
+		break;
+
 	default:
+		tb_dbg(tb, "%llx: unknown XDomain request %#x\n", route, pkg->type);
 		tb_xdp_error_response(ctl, route, sequence,
 				      ERROR_NOT_SUPPORTED);
 		break;
@@ -1000,32 +1168,38 @@ static int tb_xdomain_update_link_attributes(struct tb_xdomain *xd)
 	return 0;
 }
 
-static void tb_xdomain_get_uuid(struct work_struct *work)
+static int tb_xdomain_get_uuid(struct tb_xdomain *xd)
 {
-	struct tb_xdomain *xd = container_of(work, typeof(*xd),
-					     get_uuid_work.work);
 	struct tb *tb = xd->tb;
 	uuid_t uuid;
+	u64 route;
 	int ret;
 
 	dev_dbg(&xd->dev, "requesting remote UUID\n");
 
-	ret = tb_xdp_uuid_request(tb->ctl, xd->route, xd->uuid_retries, &uuid);
+	ret = tb_xdp_uuid_request(tb->ctl, xd->route, xd->state_retries, &uuid,
+				  &route);
 	if (ret < 0) {
-		if (xd->uuid_retries-- > 0) {
+		if (xd->state_retries-- > 0) {
 			dev_dbg(&xd->dev, "failed to request UUID, retrying\n");
-			queue_delayed_work(xd->tb->wq, &xd->get_uuid_work,
-					   msecs_to_jiffies(100));
+			return -EAGAIN;
 		} else {
 			dev_dbg(&xd->dev, "failed to read remote UUID\n");
 		}
-		return;
+		return ret;
 	}
 
 	dev_dbg(&xd->dev, "got remote UUID %pUb\n", &uuid);
 
-	if (uuid_equal(&uuid, xd->local_uuid))
-		dev_dbg(&xd->dev, "intra-domain loop detected\n");
+	if (uuid_equal(&uuid, xd->local_uuid)) {
+		if (route == xd->route)
+			dev_dbg(&xd->dev, "loop back detected\n");
+		else
+			dev_dbg(&xd->dev, "intra-domain loop detected\n");
+
+		/* Don't bond lanes automatically for loops */
+		xd->bonding_possible = false;
+	}
 
 	/*
 	 * If the UUID is different, there is another domain connected
@@ -1035,27 +1209,152 @@ static void tb_xdomain_get_uuid(struct work_struct *work)
 	if (xd->remote_uuid && !uuid_equal(&uuid, xd->remote_uuid)) {
 		dev_dbg(&xd->dev, "remote UUID is different, unplugging\n");
 		xd->is_unplugged = true;
-		return;
+		return -ENODEV;
 	}
 
 	/* First time fill in the missing UUID */
 	if (!xd->remote_uuid) {
 		xd->remote_uuid = kmemdup(&uuid, sizeof(uuid_t), GFP_KERNEL);
 		if (!xd->remote_uuid)
-			return;
+			return -ENOMEM;
 	}
 
-	/* Now we can start the normal properties exchange */
-	queue_delayed_work(xd->tb->wq, &xd->properties_changed_work,
-			   msecs_to_jiffies(100));
-	queue_delayed_work(xd->tb->wq, &xd->get_properties_work,
-			   msecs_to_jiffies(1000));
+	return 0;
 }
 
-static void tb_xdomain_get_properties(struct work_struct *work)
+static int tb_xdomain_get_link_status(struct tb_xdomain *xd)
+{
+	struct tb *tb = xd->tb;
+	u8 slw, tlw, sls, tls;
+	int ret;
+
+	dev_dbg(&xd->dev, "sending link state status request to %pUb\n",
+		xd->remote_uuid);
+
+	ret = tb_xdp_link_state_status_request(tb->ctl, xd->route,
+					       xd->state_retries, &slw, &tlw, &sls,
+					       &tls);
+	if (ret) {
+		if (ret != -EOPNOTSUPP && xd->state_retries-- > 0) {
+			dev_dbg(&xd->dev,
+				"failed to request remote link status, retrying\n");
+			return -EAGAIN;
+		}
+		dev_dbg(&xd->dev, "failed to receive remote link status\n");
+		return ret;
+	}
+
+	dev_dbg(&xd->dev, "remote link supports width %#x speed %#x\n", slw, sls);
+
+	if (slw < LANE_ADP_CS_0_SUPPORTED_WIDTH_DUAL) {
+		dev_dbg(&xd->dev, "remote adapter is single lane only\n");
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int tb_xdomain_link_state_change(struct tb_xdomain *xd,
+					unsigned int width)
+{
+	struct tb_switch *sw = tb_to_switch(xd->dev.parent);
+	struct tb_port *port = tb_port_at(xd->route, sw);
+	struct tb *tb = xd->tb;
+	u8 tlw, tls;
+	u32 val;
+	int ret;
+
+	if (width == 2)
+		tlw = LANE_ADP_CS_1_TARGET_WIDTH_DUAL;
+	else if (width == 1)
+		tlw = LANE_ADP_CS_1_TARGET_WIDTH_SINGLE;
+	else
+		return -EINVAL;
+
+	/* Use the current target speed */
+	ret = tb_port_read(port, &val, TB_CFG_PORT, port->cap_phy + LANE_ADP_CS_1, 1);
+	if (ret)
+		return ret;
+	tls = val & LANE_ADP_CS_1_TARGET_SPEED_MASK;
+
+	dev_dbg(&xd->dev, "sending link state change request with width %#x speed %#x\n",
+		tlw, tls);
+
+	ret = tb_xdp_link_state_change_request(tb->ctl, xd->route,
+					       xd->state_retries, tlw, tls);
+	if (ret) {
+		if (ret != -EOPNOTSUPP && xd->state_retries-- > 0) {
+			dev_dbg(&xd->dev,
+				"failed to change remote link state, retrying\n");
+			return -EAGAIN;
+		}
+		dev_err(&xd->dev, "failed request link state change, aborting\n");
+		return ret;
+	}
+
+	dev_dbg(&xd->dev, "received link state change response\n");
+	return 0;
+}
+
+static int tb_xdomain_bond_lanes_uuid_high(struct tb_xdomain *xd)
+{
+	struct tb_port *port;
+	int ret, width;
+
+	if (xd->target_link_width == LANE_ADP_CS_1_TARGET_WIDTH_SINGLE) {
+		width = 1;
+	} else if (xd->target_link_width == LANE_ADP_CS_1_TARGET_WIDTH_DUAL) {
+		width = 2;
+	} else {
+		if (xd->state_retries-- > 0) {
+			dev_dbg(&xd->dev,
+				"link state change request not received yet, retrying\n");
+			return -EAGAIN;
+		}
+		dev_dbg(&xd->dev, "timeout waiting for link change request\n");
+		return -ETIMEDOUT;
+	}
+
+	port = tb_port_at(xd->route, tb_xdomain_parent(xd));
+
+	/*
+	 * We can't use tb_xdomain_lane_bonding_enable() here because it
+	 * is the other side that initiates lane bonding. So here we
+	 * just set the width to both lane adapters and wait for the
+	 * link to transition bonded.
+	 */
+	ret = tb_port_set_link_width(port->dual_link_port, width);
+	if (ret) {
+		tb_port_warn(port->dual_link_port,
+			     "failed to set link width to %d\n", width);
+		return ret;
+	}
+
+	ret = tb_port_set_link_width(port, width);
+	if (ret) {
+		tb_port_warn(port, "failed to set link width to %d\n", width);
+		return ret;
+	}
+
+	ret = tb_port_wait_for_link_width(port, width, XDOMAIN_BONDING_TIMEOUT);
+	if (ret) {
+		dev_warn(&xd->dev, "error waiting for link width to become %d\n",
+			 width);
+		return ret;
+	}
+
+	port->bonded = width == 2;
+	port->dual_link_port->bonded = width == 2;
+
+	tb_port_update_credits(port);
+	tb_xdomain_update_link_attributes(xd);
+
+	dev_dbg(&xd->dev, "lane bonding %sabled\n", width == 2 ? "en" : "dis");
+	return 0;
+}
+
+static int tb_xdomain_get_properties(struct tb_xdomain *xd)
 {
-	struct tb_xdomain *xd = container_of(work, typeof(*xd),
-					     get_properties_work.work);
 	struct tb_property_dir *dir;
 	struct tb *tb = xd->tb;
 	bool update = false;
@@ -1066,34 +1365,35 @@ static void tb_xdomain_get_properties(struct work_struct *work)
 	dev_dbg(&xd->dev, "requesting remote properties\n");
 
 	ret = tb_xdp_properties_request(tb->ctl, xd->route, xd->local_uuid,
-					xd->remote_uuid, xd->properties_retries,
+					xd->remote_uuid, xd->state_retries,
 					&block, &gen);
 	if (ret < 0) {
-		if (xd->properties_retries-- > 0) {
+		if (xd->state_retries-- > 0) {
 			dev_dbg(&xd->dev,
 				"failed to request remote properties, retrying\n");
-			queue_delayed_work(xd->tb->wq, &xd->get_properties_work,
-					   msecs_to_jiffies(1000));
+			return -EAGAIN;
 		} else {
 			/* Give up now */
 			dev_err(&xd->dev,
 				"failed read XDomain properties from %pUb\n",
 				xd->remote_uuid);
 		}
-		return;
-	}
 
-	xd->properties_retries = XDOMAIN_PROPERTIES_RETRIES;
+		return ret;
+	}
 
 	mutex_lock(&xd->lock);
 
 	/* Only accept newer generation properties */
-	if (xd->remote_properties && gen <= xd->remote_property_block_gen)
+	if (xd->remote_properties && gen <= xd->remote_property_block_gen) {
+		ret = 0;
 		goto err_free_block;
+	}
 
 	dir = tb_property_parse_dir(block, ret);
 	if (!dir) {
 		dev_err(&xd->dev, "failed to parse XDomain properties\n");
+		ret = -ENOMEM;
 		goto err_free_block;
 	}
 
@@ -1124,9 +1424,16 @@ static void tb_xdomain_get_properties(struct work_struct *work)
 	 * registered, we notify the userspace that it has changed.
 	 */
 	if (!update) {
+		struct tb_port *port;
+
+		/* Now disable lane 1 if bonding was not enabled */
+		port = tb_port_at(xd->route, tb_xdomain_parent(xd));
+		if (!port->bonded)
+			tb_port_disable(port->dual_link_port);
+
 		if (device_add(&xd->dev)) {
 			dev_err(&xd->dev, "failed to add XDomain device\n");
-			return;
+			return -ENODEV;
 		}
 		dev_info(&xd->dev, "new host found, vendor=%#x device=%#x\n",
 			 xd->vendor, xd->device);
@@ -1138,13 +1445,193 @@ static void tb_xdomain_get_properties(struct work_struct *work)
 	}
 
 	enumerate_services(xd);
-	return;
+	return 0;
 
 err_free_dir:
 	tb_property_free_dir(dir);
 err_free_block:
 	kfree(block);
 	mutex_unlock(&xd->lock);
+
+	return ret;
+}
+
+static void tb_xdomain_queue_uuid(struct tb_xdomain *xd)
+{
+	xd->state = XDOMAIN_STATE_UUID;
+	xd->state_retries = XDOMAIN_RETRIES;
+	queue_delayed_work(xd->tb->wq, &xd->state_work,
+			   msecs_to_jiffies(XDOMAIN_SHORT_TIMEOUT));
+}
+
+static void tb_xdomain_queue_link_status(struct tb_xdomain *xd)
+{
+	xd->state = XDOMAIN_STATE_LINK_STATUS;
+	xd->state_retries = XDOMAIN_RETRIES;
+	queue_delayed_work(xd->tb->wq, &xd->state_work,
+			   msecs_to_jiffies(XDOMAIN_DEFAULT_TIMEOUT));
+}
+
+static void tb_xdomain_queue_link_status2(struct tb_xdomain *xd)
+{
+	xd->state = XDOMAIN_STATE_LINK_STATUS2;
+	xd->state_retries = XDOMAIN_RETRIES;
+	queue_delayed_work(xd->tb->wq, &xd->state_work,
+			   msecs_to_jiffies(XDOMAIN_DEFAULT_TIMEOUT));
+}
+
+static void tb_xdomain_queue_bonding(struct tb_xdomain *xd)
+{
+	if (memcmp(xd->local_uuid, xd->remote_uuid, UUID_SIZE) > 0) {
+		dev_dbg(&xd->dev, "we have higher UUID, other side bonds the lanes\n");
+		xd->state = XDOMAIN_STATE_BONDING_UUID_HIGH;
+	} else {
+		dev_dbg(&xd->dev, "we have lower UUID, bonding lanes\n");
+		xd->state = XDOMAIN_STATE_LINK_STATE_CHANGE;
+	}
+
+	xd->state_retries = XDOMAIN_RETRIES;
+	queue_delayed_work(xd->tb->wq, &xd->state_work,
+			   msecs_to_jiffies(XDOMAIN_DEFAULT_TIMEOUT));
+}
+
+static void tb_xdomain_queue_bonding_uuid_low(struct tb_xdomain *xd)
+{
+	xd->state = XDOMAIN_STATE_BONDING_UUID_LOW;
+	xd->state_retries = XDOMAIN_RETRIES;
+	queue_delayed_work(xd->tb->wq, &xd->state_work,
+			   msecs_to_jiffies(XDOMAIN_DEFAULT_TIMEOUT));
+}
+
+static void tb_xdomain_queue_properties(struct tb_xdomain *xd)
+{
+	xd->state = XDOMAIN_STATE_PROPERTIES;
+	xd->state_retries = XDOMAIN_RETRIES;
+	queue_delayed_work(xd->tb->wq, &xd->state_work,
+			   msecs_to_jiffies(XDOMAIN_DEFAULT_TIMEOUT));
+}
+
+static void tb_xdomain_queue_properties_changed(struct tb_xdomain *xd)
+{
+	xd->properties_changed_retries = XDOMAIN_RETRIES;
+	queue_delayed_work(xd->tb->wq, &xd->properties_changed_work,
+			   msecs_to_jiffies(XDOMAIN_SHORT_TIMEOUT));
+}
+
+static void tb_xdomain_state_work(struct work_struct *work)
+{
+	struct tb_xdomain *xd = container_of(work, typeof(*xd), state_work.work);
+	int ret, state = xd->state;
+
+	if (WARN_ON_ONCE(state < XDOMAIN_STATE_INIT ||
+			 state > XDOMAIN_STATE_ERROR))
+		return;
+
+	dev_dbg(&xd->dev, "running state %s\n", state_names[state]);
+
+	switch (state) {
+	case XDOMAIN_STATE_INIT:
+		if (xd->needs_uuid) {
+			tb_xdomain_queue_uuid(xd);
+		} else {
+			tb_xdomain_queue_properties_changed(xd);
+			tb_xdomain_queue_properties(xd);
+		}
+		break;
+
+	case XDOMAIN_STATE_UUID:
+		ret = tb_xdomain_get_uuid(xd);
+		if (ret) {
+			if (ret == -EAGAIN)
+				goto retry_state;
+			xd->state = XDOMAIN_STATE_ERROR;
+		} else {
+			tb_xdomain_queue_properties_changed(xd);
+			if (xd->bonding_possible)
+				tb_xdomain_queue_link_status(xd);
+			else
+				tb_xdomain_queue_properties(xd);
+		}
+		break;
+
+	case XDOMAIN_STATE_LINK_STATUS:
+		ret = tb_xdomain_get_link_status(xd);
+		if (ret) {
+			if (ret == -EAGAIN)
+				goto retry_state;
+
+			/*
+			 * If any of the lane bonding states fail we skip
+			 * bonding completely and try to continue from
+			 * reading properties.
+			 */
+			tb_xdomain_queue_properties(xd);
+		} else {
+			tb_xdomain_queue_bonding(xd);
+		}
+		break;
+
+	case XDOMAIN_STATE_LINK_STATE_CHANGE:
+		ret = tb_xdomain_link_state_change(xd, 2);
+		if (ret) {
+			if (ret == -EAGAIN)
+				goto retry_state;
+			tb_xdomain_queue_properties(xd);
+		} else {
+			tb_xdomain_queue_link_status2(xd);
+		}
+		break;
+
+	case XDOMAIN_STATE_LINK_STATUS2:
+		ret = tb_xdomain_get_link_status(xd);
+		if (ret) {
+			if (ret == -EAGAIN)
+				goto retry_state;
+			tb_xdomain_queue_properties(xd);
+		} else {
+			tb_xdomain_queue_bonding_uuid_low(xd);
+		}
+		break;
+
+	case XDOMAIN_STATE_BONDING_UUID_LOW:
+		tb_xdomain_lane_bonding_enable(xd);
+		tb_xdomain_queue_properties(xd);
+		break;
+
+	case XDOMAIN_STATE_BONDING_UUID_HIGH:
+		if (tb_xdomain_bond_lanes_uuid_high(xd) == -EAGAIN)
+			goto retry_state;
+		tb_xdomain_queue_properties(xd);
+		break;
+
+	case XDOMAIN_STATE_PROPERTIES:
+		ret = tb_xdomain_get_properties(xd);
+		if (ret) {
+			if (ret == -EAGAIN)
+				goto retry_state;
+			xd->state = XDOMAIN_STATE_ERROR;
+		} else {
+			xd->state = XDOMAIN_STATE_ENUMERATED;
+		}
+		break;
+
+	case XDOMAIN_STATE_ENUMERATED:
+		tb_xdomain_queue_properties(xd);
+		break;
+
+	case XDOMAIN_STATE_ERROR:
+		break;
+
+	default:
+		dev_warn(&xd->dev, "unexpected state %d\n", state);
+		break;
+	}
+
+	return;
+
+retry_state:
+	queue_delayed_work(xd->tb->wq, &xd->state_work,
+			   msecs_to_jiffies(XDOMAIN_DEFAULT_TIMEOUT));
 }
 
 static void tb_xdomain_properties_changed(struct work_struct *work)
@@ -1163,13 +1650,13 @@ static void tb_xdomain_properties_changed(struct work_struct *work)
 				"failed to send properties changed notification, retrying\n");
 			queue_delayed_work(xd->tb->wq,
 					   &xd->properties_changed_work,
-					   msecs_to_jiffies(1000));
+					   msecs_to_jiffies(XDOMAIN_DEFAULT_TIMEOUT));
 		}
 		dev_err(&xd->dev, "failed to send properties changed notification\n");
 		return;
 	}
 
-	xd->properties_changed_retries = XDOMAIN_PROPERTIES_CHANGED_RETRIES;
+	xd->properties_changed_retries = XDOMAIN_RETRIES;
 }
 
 static ssize_t device_show(struct device *dev, struct device_attribute *attr,
@@ -1304,31 +1791,17 @@ static void tb_xdomain_release(struct device *dev)
 
 static void start_handshake(struct tb_xdomain *xd)
 {
-	xd->uuid_retries = XDOMAIN_UUID_RETRIES;
-	xd->properties_retries = XDOMAIN_PROPERTIES_RETRIES;
-	xd->properties_changed_retries = XDOMAIN_PROPERTIES_CHANGED_RETRIES;
-
-	if (xd->needs_uuid) {
-		queue_delayed_work(xd->tb->wq, &xd->get_uuid_work,
-				   msecs_to_jiffies(100));
-	} else {
-		/* Start exchanging properties with the other host */
-		queue_delayed_work(xd->tb->wq, &xd->properties_changed_work,
-				   msecs_to_jiffies(100));
-		queue_delayed_work(xd->tb->wq, &xd->get_properties_work,
-				   msecs_to_jiffies(1000));
-	}
+	xd->state = XDOMAIN_STATE_INIT;
+	queue_delayed_work(xd->tb->wq, &xd->state_work,
+			   msecs_to_jiffies(XDOMAIN_SHORT_TIMEOUT));
 }
 
 static void stop_handshake(struct tb_xdomain *xd)
 {
-	xd->uuid_retries = 0;
-	xd->properties_retries = 0;
-	xd->properties_changed_retries = 0;
-
-	cancel_delayed_work_sync(&xd->get_uuid_work);
-	cancel_delayed_work_sync(&xd->get_properties_work);
 	cancel_delayed_work_sync(&xd->properties_changed_work);
+	cancel_delayed_work_sync(&xd->state_work);
+	xd->properties_changed_retries = 0;
+	xd->state_retries = 0;
 }
 
 static int __maybe_unused tb_xdomain_suspend(struct device *dev)
@@ -1389,8 +1862,7 @@ struct tb_xdomain *tb_xdomain_alloc(struct tb *tb, struct device *parent,
 	ida_init(&xd->in_hopids);
 	ida_init(&xd->out_hopids);
 	mutex_init(&xd->lock);
-	INIT_DELAYED_WORK(&xd->get_uuid_work, tb_xdomain_get_uuid);
-	INIT_DELAYED_WORK(&xd->get_properties_work, tb_xdomain_get_properties);
+	INIT_DELAYED_WORK(&xd->state_work, tb_xdomain_state_work);
 	INIT_DELAYED_WORK(&xd->properties_changed_work,
 			  tb_xdomain_properties_changed);
 
@@ -1405,6 +1877,7 @@ struct tb_xdomain *tb_xdomain_alloc(struct tb *tb, struct device *parent,
 			goto err_free_local_uuid;
 	} else {
 		xd->needs_uuid = true;
+		xd->bonding_possible = !!down->dual_link_port;
 	}
 
 	device_initialize(&xd->dev);
@@ -1523,9 +1996,9 @@ int tb_xdomain_lane_bonding_enable(struct tb_xdomain *xd)
 		return ret;
 	}
 
-	ret = tb_port_wait_for_link_width(port, 2, 100);
+	ret = tb_port_wait_for_link_width(port, 2, XDOMAIN_BONDING_TIMEOUT);
 	if (ret) {
-		tb_port_warn(port, "timeout enabling lane bonding\n");
+		tb_port_warn(port, "failed to enable lane bonding\n");
 		return ret;
 	}
 
diff --git a/include/linux/thunderbolt.h b/include/linux/thunderbolt.h
index 124e13cb1469..e13fe15e6a51 100644
--- a/include/linux/thunderbolt.h
+++ b/include/linux/thunderbolt.h
@@ -198,15 +198,15 @@ void tb_unregister_property_dir(const char *key, struct tb_property_dir *dir);
  * @local_property_block_len: Length of the @local_property_block in dwords
  * @remote_properties: Properties exported by the remote domain
  * @remote_property_block_gen: Generation of @remote_properties
- * @get_uuid_work: Work used to retrieve @remote_uuid
- * @uuid_retries: Number of times left @remote_uuid is requested before
- *		  giving up
- * @get_properties_work: Work used to get remote domain properties
- * @properties_retries: Number of times left to read properties
+ * @state: Next XDomain discovery state to run
+ * @state_work: Work used to run the next state
+ * @state_retries: Number of retries remain for the state
  * @properties_changed_work: Work used to notify the remote domain that
  *			     our properties have changed
  * @properties_changed_retries: Number of times left to send properties
  *				changed notification
+ * @bonding_possible: True if lane bonding is possible on local side
+ * @target_link_width: Target link width from the remote host
  * @link: Root switch link the remote domain is connected (ICM only)
  * @depth: Depth in the chain the remote domain is connected (ICM only)
  *
@@ -244,12 +244,13 @@ struct tb_xdomain {
 	u32 local_property_block_len;
 	struct tb_property_dir *remote_properties;
 	u32 remote_property_block_gen;
-	struct delayed_work get_uuid_work;
-	int uuid_retries;
-	struct delayed_work get_properties_work;
-	int properties_retries;
+	int state;
+	struct delayed_work state_work;
+	int state_retries;
 	struct delayed_work properties_changed_work;
 	int properties_changed_retries;
+	bool bonding_possible;
+	u8 target_link_width;
 	u8 link;
 	u8 depth;
 };