[1/3] thunderbolt: Log a warning if device links are not found

diff --git a/drivers/thunderbolt/acpi.c b/drivers/thunderbolt/acpi.c
index 38fefd0e5268..c9b6bb46111c 100644
--- a/drivers/thunderbolt/acpi.c
+++ b/drivers/thunderbolt/acpi.c
@@ -12,7 +12,7 @@ 
 #include "tb.h"
 
 static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data,
-				    void **return_value)
+				    void **ret)
 {
 	struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 	struct fwnode_handle *fwnode;
@@ -84,6 +84,7 @@  static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data,
 		if (link) {
 			dev_dbg(&nhi->pdev->dev, "created link from %s\n",
 				dev_name(&pdev->dev));
+			*(bool *)ret = true;
 		} else {
 			dev_warn(&nhi->pdev->dev, "device link creation from %s failed\n",
 				 dev_name(&pdev->dev));
@@ -104,22 +105,29 @@  static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data,
  * Goes over ACPI namespace finding tunneled ports that reference to
  * @nhi ACPI node. For each reference a device link is added. The link
  * is automatically removed by the driver core.
+ *
+ * Returns %true if at least one link was created.
  */
-void tb_acpi_add_links(struct tb_nhi *nhi)
+bool tb_acpi_add_links(struct tb_nhi *nhi)
 {
 	acpi_status status;
+	bool ret = false;
 
 	if (!has_acpi_companion(&nhi->pdev->dev))
-		return;
+		return false;
 
 	/*
 	 * Find all devices that have usb4-host-controller interface
 	 * property that references to this NHI.
 	 */
 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 32,
-				     tb_acpi_add_link, NULL, nhi, NULL);
-	if (ACPI_FAILURE(status))
+				     tb_acpi_add_link, NULL, nhi, (void **)&ret);
+	if (ACPI_FAILURE(status)) {
 		dev_warn(&nhi->pdev->dev, "failed to enumerate tunneled ports\n");
+		return false;
+	}
+
+	return ret;
 }
 
 /**
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 3fb4553a6442..dd0a1ef8cf12 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -2368,12 +2368,13 @@  static const struct tb_cm_ops tb_cm_ops = {
  * downstream ports and the NHI so that the device core will make sure
  * NHI is resumed first before the rest.
  */
-static void tb_apple_add_links(struct tb_nhi *nhi)
+static bool tb_apple_add_links(struct tb_nhi *nhi)
 {
 	struct pci_dev *upstream, *pdev;
+	bool ret;
 
 	if (!x86_apple_machine)
-		return;
+		return false;
 
 	switch (nhi->pdev->device) {
 	case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
@@ -2382,26 +2383,27 @@  static void tb_apple_add_links(struct tb_nhi *nhi)
 	case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI:
 		break;
 	default:
-		return;
+		return false;
 	}
 
 	upstream = pci_upstream_bridge(nhi->pdev);
 	while (upstream) {
 		if (!pci_is_pcie(upstream))
-			return;
+			return false;
 		if (pci_pcie_type(upstream) == PCI_EXP_TYPE_UPSTREAM)
 			break;
 		upstream = pci_upstream_bridge(upstream);
 	}
 
 	if (!upstream)
-		return;
+		return false;
 
 	/*
 	 * For each hotplug downstream port, create add device link
 	 * back to NHI so that PCIe tunnels can be re-established after
 	 * sleep.
 	 */
+	ret = false;
 	for_each_pci_bridge(pdev, upstream->subordinate) {
 		const struct device_link *link;
 
@@ -2417,11 +2419,14 @@  static void tb_apple_add_links(struct tb_nhi *nhi)
 		if (link) {
 			dev_dbg(&nhi->pdev->dev, "created link from %s\n",
 				dev_name(&pdev->dev));
+			ret = true;
 		} else {
 			dev_warn(&nhi->pdev->dev, "device link creation from %s failed\n",
 				 dev_name(&pdev->dev));
 		}
 	}
+
+	return ret;
 }
 
 struct tb *tb_probe(struct tb_nhi *nhi)
@@ -2448,8 +2453,13 @@  struct tb *tb_probe(struct tb_nhi *nhi)
 
 	tb_dbg(tb, "using software connection manager\n");
 
-	tb_apple_add_links(nhi);
-	tb_acpi_add_links(nhi);
+	/*
+	 * Device links are needed to make sure we establish tunnels
+	 * before the PCIe/USB stack is resumed so complain here if we
+	 * found them missing.
+	 */
+	if (!tb_apple_add_links(nhi) && !tb_acpi_add_links(nhi))
+		tb_warn(tb, "device links to tunneled native ports are missing!\n");
 
 	return tb;
 }
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 57a9b272cb94..d2a55ad2fd3e 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -1333,7 +1333,7 @@  static inline bool usb4_port_device_is_offline(const struct usb4_port *usb4)
 void tb_check_quirks(struct tb_switch *sw);
 
 #ifdef CONFIG_ACPI
-void tb_acpi_add_links(struct tb_nhi *nhi);
+bool tb_acpi_add_links(struct tb_nhi *nhi);
 
 bool tb_acpi_is_native(void);
 bool tb_acpi_may_tunnel_usb3(void);
@@ -1346,7 +1346,7 @@  void tb_acpi_exit(void);
 int tb_acpi_power_on_retimers(struct tb_port *port);
 int tb_acpi_power_off_retimers(struct tb_port *port);
 #else
-static inline void tb_acpi_add_links(struct tb_nhi *nhi) { }
+static inline bool tb_acpi_add_links(struct tb_nhi *nhi) { return false; }
 
 static inline bool tb_acpi_is_native(void) { return true; }
 static inline bool tb_acpi_may_tunnel_usb3(void) { return true; }