4 files changed, 83 insertions, 22 deletions

diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index fcad5f9d12f0..048c797f394c 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -84,6 +84,7 @@ struct usb_hub {
  * @port_owner: port's owner
  * @peer: related usb2 and usb3 ports (share the same connector)
  * @connect_type: port's connect type
+ * @location: opaque representation of platform connector location
  * @portnum: port index num based one
  * @power_is_on: port's power state
  * @did_runtime_put: port has done pm_runtime_put().
@@ -94,6 +95,7 @@ struct usb_port {
         struct usb_dev_state *port_owner;
         struct usb_port *peer;
         enum usb_port_connect_type connect_type;
+        usb_port_location_t location;
         u8 portnum;
         unsigned power_is_on:1;
         unsigned did_runtime_put:1;
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 9b7496b52f2a..aea54e8dfe47 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -188,8 +188,42 @@ static void unlink_peers(struct usb_port *left, struct usb_port *right)
 }
 
 /*
- * Set the default peer port for root hubs, or via the upstream peer
- * relationship for all other hubs
+ * For each usb hub device in the system check to see if it is in the
+ * peer domain of the given port_dev, and if it is check to see if it
+ * has a port that matches the given port by location
+ */
+static int match_location(struct usb_device *peer_hdev, void *p)
+{
+        int port1;
+        struct usb_hcd *hcd, *peer_hcd;
+        struct usb_port *port_dev = p, *peer;
+        struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
+        struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
+
+        if (!peer_hub)
+                return 0;
+
+        hcd = bus_to_hcd(hdev->bus);
+        peer_hcd = bus_to_hcd(peer_hdev->bus);
+        /* peer_hcd is provisional until we verify it against the known peer */
+        if (peer_hcd != hcd->shared_hcd)
+                return 0;
+
+        for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
+                peer = peer_hub->ports[port1 - 1];
+                if (peer && peer->location == port_dev->location) {
+                        link_peers(port_dev, peer);
+                        return 1; /* done */
+                }
+        }
+
+        return 0;
+}
+
+/*
+ * Find the peer port either via explicit platform firmware "location"
+ * data, the peer hcd for root hubs, or the upstream peer relationship
+ * for all other hubs.
  */
 static void find_and_link_peer(struct usb_hub *hub, int port1)
 {
@@ -198,7 +232,17 @@ static void find_and_link_peer(struct usb_hub *hub, int port1)
         struct usb_device *peer_hdev;
         struct usb_hub *peer_hub;
 
-        if (!hdev->parent) {
+        /*
+         * If location data is available then we can only peer this port
+         * by a location match, not the default peer (lest we create a
+         * situation where we need to go back and undo a default peering
+         * when the port is later peered by location data)
+         */
+        if (port_dev->location) {
+                /* we link the peer in match_location() if found */
+                usb_for_each_dev(port_dev, match_location);
+                return;
+        } else if (!hdev->parent) {
                 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
                 struct usb_hcd *peer_hcd = hcd->shared_hcd;
 
@@ -225,8 +269,12 @@ static void find_and_link_peer(struct usb_hub *hub, int port1)
         if (!peer_hub || port1 > peer_hdev->maxchild)
                 return;
 
+        /*
+         * we found a valid default peer, last check is to make sure it
+         * does not have location data
+         */
         peer = peer_hub->ports[port1 - 1];
-        if (peer)
+        if (peer && peer->location == 0)
                 link_peers(port_dev, peer);
 }
 
diff --git a/drivers/usb/core/usb-acpi.c b/drivers/usb/core/usb-acpi.c
index d3e7e1b4125e..2776cfe64c09 100644
--- a/drivers/usb/core/usb-acpi.c
+++ b/drivers/usb/core/usb-acpi.c
@@ -85,19 +85,13 @@ int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
 }
 EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
 
-static int usb_acpi_check_port_connect_type(struct usb_device *hdev,
-        acpi_handle handle, int port1)
+static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle,
+                struct acpi_pld_info *pld)
 {
         enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-        struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
-        struct acpi_pld_info *pld;
         union acpi_object *upc;
         acpi_status status;
-        int ret = 0;
-
-        if (!hub)
-                return 0;
 
         /*
          * According to ACPI Spec 9.13. PLD indicates whether usb port is
@@ -107,15 +101,10 @@ static int usb_acpi_check_port_connect_type(struct usb_device *hdev,
          * a usb device is directly hard-wired to the port. If no visible and
          * no connectable, the port would be not used.
          */
-        status = acpi_get_physical_device_location(handle, &pld);
-        if (ACPI_FAILURE(status))
-                return -ENODEV;
-
         status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
         upc = buffer.pointer;
         if (!upc || (upc->type != ACPI_TYPE_PACKAGE)
                 || upc->package.count != 4) {
-                ret = -EINVAL;
                 goto out;
         }
 
@@ -126,14 +115,18 @@ static int usb_acpi_check_port_connect_type(struct usb_device *hdev,
                         connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
         else if (!pld->user_visible)
                 connect_type = USB_PORT_NOT_USED;
-        hub->ports[port1 - 1]->connect_type = connect_type;
-
 out:
-        ACPI_FREE(pld);
         kfree(upc);
-        return ret;
+        return connect_type;
 }
 
+
+/*
+ * Private to usb-acpi, all the core needs to know is that
+ * port_dev->location is non-zero when it has been set by the firmware.
+ */
+#define USB_ACPI_LOCATION_VALID (1 << 31)
+
 static struct acpi_device *usb_acpi_find_companion(struct device *dev)
 {
         struct usb_device *udev;
@@ -164,6 +157,9 @@ static struct acpi_device *usb_acpi_find_companion(struct device *dev)
         } else if (is_usb_port(dev)) {
                 struct usb_port *port_dev = to_usb_port(dev);
                 int port1 = port_dev->portnum;
+                struct acpi_pld_info *pld;
+                acpi_handle *handle;
+                acpi_status status;
 
                 /* Get the struct usb_device point of port's hub */
                 udev = to_usb_device(dev->parent->parent);
@@ -194,7 +190,16 @@ static struct acpi_device *usb_acpi_find_companion(struct device *dev)
                         if (!adev)
                                 return NULL;
                 }
-                usb_acpi_check_port_connect_type(udev, adev->handle, port1);
+                handle = adev->handle;
+                status = acpi_get_physical_device_location(handle, &pld);
+                if (ACPI_FAILURE(status) || !pld)
+                        return adev;
+
+                port_dev->location = USB_ACPI_LOCATION_VALID
+                        | pld->group_token << 8 | pld->group_position;
+                port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
+                ACPI_FREE(pld);
+
                 return adev;
         }
 
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index 6afa738b5ba4..98dc08e13448 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -171,6 +171,12 @@ extern void usbfs_conn_disc_event(void);
 extern int usb_devio_init(void);
 extern void usb_devio_cleanup(void);
 
+/*
+ * Firmware specific cookie identifying a port's location. '0' == no location
+ * data available
+ */
+typedef u32 usb_port_location_t;
+
 /* internal notify stuff */
 extern void usb_notify_add_device(struct usb_device *udev);
 extern void usb_notify_remove_device(struct usb_device *udev);