thunderbolt: Log a warning if device links are not found

The software connection manager needs the device links in order to
establish the tunnels before the native protocols so log a warning if
they are not found.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

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 @@ out_put:
  * 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;
 }
 
 /**

drivers/thunderbolt/tb.c

@@ -2366,12 +2366,13 @@ 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:
@@ -2380,26 +2381,27 @@ 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;
 
@@ -2415,11 +2417,14 @@ 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)
@@ -2446,8 +2451,13 @@ 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;
 }

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; }