1 files changed, 55 insertions, 17 deletions

diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index b1b85abb9a2..0daff0d968b 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -64,6 +64,43 @@ MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
 
 
 /**
+ * usb_find_alt_setting() - Given a configuration, find the alternate setting
+ * for the given interface.
+ * @config: the configuration to search (not necessarily the current config).
+ * @iface_num: interface number to search in
+ * @alt_num: alternate interface setting number to search for.
+ *
+ * Search the configuration's interface cache for the given alt setting.
+ */
+struct usb_host_interface *usb_find_alt_setting(
+		struct usb_host_config *config,
+		unsigned int iface_num,
+		unsigned int alt_num)
+{
+	struct usb_interface_cache *intf_cache = NULL;
+	int i;
+
+	for (i = 0; i < config->desc.bNumInterfaces; i++) {
+		if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
+				== iface_num) {
+			intf_cache = config->intf_cache[i];
+			break;
+		}
+	}
+	if (!intf_cache)
+		return NULL;
+	for (i = 0; i < intf_cache->num_altsetting; i++)
+		if (intf_cache->altsetting[i].desc.bAlternateSetting == alt_num)
+			return &intf_cache->altsetting[i];
+
+	printk(KERN_DEBUG "Did not find alt setting %u for intf %u, "
+			"config %u\n", alt_num, iface_num,
+			config->desc.bConfigurationValue);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(usb_find_alt_setting);
+
+/**
  * usb_ifnum_to_if - get the interface object with a given interface number
  * @dev: the device whose current configuration is considered
  * @ifnum: the desired interface
@@ -132,7 +169,7 @@ EXPORT_SYMBOL_GPL(usb_altnum_to_altsetting);
 
 struct find_interface_arg {
 	int minor;
-	struct usb_interface *interface;
+	struct device_driver *drv;
 };
 
 static int __find_interface(struct device *dev, void *data)
@@ -143,12 +180,10 @@ static int __find_interface(struct device *dev, void *data)
 	if (!is_usb_interface(dev))
 		return 0;
 
+	if (dev->driver != arg->drv)
+		return 0;
 	intf = to_usb_interface(dev);
-	if (intf->minor != -1 && intf->minor == arg->minor) {
-		arg->interface = intf;
-		return 1;
-	}
-	return 0;
+	return intf->minor == arg->minor;
 }
 
 /**
@@ -156,21 +191,24 @@ static int __find_interface(struct device *dev, void *data)
  * @drv: the driver whose current configuration is considered
  * @minor: the minor number of the desired device
  *
- * This walks the driver device list and returns a pointer to the interface
- * with the matching minor.  Note, this only works for devices that share the
- * USB major number.
+ * This walks the bus device list and returns a pointer to the interface
+ * with the matching minor and driver.  Note, this only works for devices
+ * that share the USB major number.
  */
 struct usb_interface *usb_find_interface(struct usb_driver *drv, int minor)
 {
 	struct find_interface_arg argb;
-	int retval;
+	struct device *dev;
 
 	argb.minor = minor;
-	argb.interface = NULL;
-	/* eat the error, it will be in argb.interface */
-	retval = driver_for_each_device(&drv->drvwrap.driver, NULL, &argb,
-					__find_interface);
-	return argb.interface;
+	argb.drv = &drv->drvwrap.driver;
+
+	dev = bus_find_device(&usb_bus_type, NULL, &argb, __find_interface);
+
+	/* Drop reference count from bus_find_device */
+	put_device(dev);
+
+	return dev ? to_usb_interface(dev) : NULL;
 }
 EXPORT_SYMBOL_GPL(usb_find_interface);
 
@@ -291,7 +329,7 @@ static int usb_dev_restore(struct device *dev)
 	return usb_resume(dev, PMSG_RESTORE);
 }
 
-static struct dev_pm_ops usb_device_pm_ops = {
+static const struct dev_pm_ops usb_device_pm_ops = {
 	.prepare =	usb_dev_prepare,
 	.complete =	usb_dev_complete,
 	.suspend =	usb_dev_suspend,
@@ -1038,7 +1076,7 @@ static struct notifier_block usb_bus_nb = {
 struct dentry *usb_debug_root;
 EXPORT_SYMBOL_GPL(usb_debug_root);
 
-struct dentry *usb_debug_devices;
+static struct dentry *usb_debug_devices;
 
 static int usb_debugfs_init(void)
 {