kernel: start working on 3.18 support

[openwrt/openwrt.git] / target / linux / generic / patches-3.18 / 820-usb_add_usb_find_device_by_name.patch

diff --git a/target/linux/generic/patches-3.18/820-usb_add_usb_find_device_by_name.patch b/target/linux/generic/patches-3.18/820-usb_add_usb_find_device_by_name.patch
new file mode 100644 (file)
index 0000000..ad0ec06
--- /dev/null
+++ b/target/linux/generic/patches-3.18/820-usb_add_usb_find_device_by_name.patch
@@ -0,0 +1,84 @@
+--- a/drivers/usb/core/usb.c
++++ b/drivers/usb/core/usb.c
+@@ -690,6 +690,71 @@ int __usb_get_extra_descriptor(char *buf
+ }
+ EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
+ 
++static struct usb_device *match_device_name(struct usb_device *dev,
++                                          const char *name)
++{
++      struct usb_device *ret_dev = NULL;
++      struct usb_device *childdev = NULL;
++      int child;
++
++      dev_dbg(&dev->dev, "check for name %s ...\n", name);
++
++      /* see if this device matches */
++      if (strcmp(dev_name(&dev->dev), name) == 0 ) {
++              dev_dbg(&dev->dev, "matched this device!\n");
++              ret_dev = usb_get_dev(dev);
++              goto exit;
++      }
++      /* look through all of the children of this device */
++      usb_hub_for_each_child(dev, child, childdev) {
++              if (childdev) {
++                      usb_lock_device(childdev);
++                      ret_dev = match_device_name(childdev, name);
++                      usb_unlock_device(childdev);
++                      if (ret_dev)
++                              goto exit;
++              }
++      }
++exit:
++      return ret_dev;
++}
++
++/**
++ * usb_find_device_by_name - find a specific usb device in the system
++ * @name: the name of the device to find
++ *
++ * Returns a pointer to a struct usb_device if such a specified usb
++ * device is present in the system currently.  The usage count of the
++ * device will be incremented if a device is found.  Make sure to call
++ * usb_put_dev() when the caller is finished with the device.
++ *
++ * If a device with the specified bus id is not found, NULL is returned.
++ */
++struct usb_device *usb_find_device_by_name(const char *name)
++{
++      struct list_head *buslist;
++      struct usb_bus *bus;
++      struct usb_device *dev = NULL;
++
++      mutex_lock(&usb_bus_list_lock);
++      for (buslist = usb_bus_list.next;
++           buslist != &usb_bus_list;
++           buslist = buslist->next) {
++              bus = container_of(buslist, struct usb_bus, bus_list);
++              if (!bus->root_hub)
++                      continue;
++              usb_lock_device(bus->root_hub);
++              dev = match_device_name(bus->root_hub, name);
++              usb_unlock_device(bus->root_hub);
++              if (dev)
++                      goto exit;
++      }
++exit:
++      mutex_unlock(&usb_bus_list_lock);
++      return dev;
++}
++EXPORT_SYMBOL_GPL(usb_find_device_by_name);
++
+ /**
+  * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
+  * @dev: device the buffer will be used with
+--- a/include/linux/usb.h
++++ b/include/linux/usb.h
+@@ -700,6 +700,7 @@ static inline bool usb_device_no_sg_cons
+       return udev && udev->bus && udev->bus->no_sg_constraint;
+ }
+ 
++extern struct usb_device *usb_find_device_by_name(const char *name);
+ 
+ /*-------------------------------------------------------------------------*/
+