usb: move children to struct usb_port

The usb_device structure contains an array of usb_device "children".
This array is only valid if the usb_device is a hub, so it makes no
sense to store it there.  Instead, store the usb_device child
in its parent usb_port structure.

Since usb_port is an internal USB core structure, add a new function to
get the USB device child, usb_hub_find_child().  Add a new macro,
usb_hub_get_each_child(), to iterate over all the children attached to a
particular USB hub.

Remove the printing the USB children array pointer from the usb-ip
driver, since it's really not necessary.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 13 insertions, 2 deletions

diff --git a/include/linux/usb.h b/include/linux/usb.h
index 30d1ae38eab1..ff8ef2d28589 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -469,7 +469,6 @@ struct usb3_lpm_parameters {
  *      access from userspace
  * @usbfs_dentry: usbfs dentry entry for the device
  * @maxchild: number of ports if hub
- * @children: child devices - USB devices that are attached to this hub
  * @quirks: quirks of the whole device
  * @urbnum: number of URBs submitted for the whole device
  * @active_duration: total time device is not suspended
@@ -543,7 +542,6 @@ struct usb_device {
         struct list_head filelist;
 
         int maxchild;
-        struct usb_device **children;
 
         u32 quirks;
         atomic_t urbnum;
@@ -572,6 +570,19 @@ static inline struct usb_device *interface_to_usbdev(struct usb_interface *intf)
 
 extern struct usb_device *usb_get_dev(struct usb_device *dev);
 extern void usb_put_dev(struct usb_device *dev);
+extern struct usb_device *usb_hub_find_child(struct usb_device *hdev,
+        int port1);
+
+/**
+ * usb_hub_for_each_child - iterate over all child devices on the hub
+ * @hdev:  USB device belonging to the usb hub
+ * @port1: portnum associated with child device
+ * @child: child device pointer
+ */
+#define usb_hub_for_each_child(hdev, port1, child) \
+        for (port1 = 1, child = usb_hub_find_child(hdev, port1); \
+                port1 <= hdev->maxchild; \
+                child = usb_hub_find_child(hdev, ++port1))
 
 /* USB device locking */
 #define usb_lock_device(udev)           device_lock(&(udev)->dev)