usbcore: store each usb_device's level in the tree

This patch (as778) adds a field to struct usb_device to store the
device's level in the USB tree.  In itself this number isn't really
important.  But the overhead is very low, and in a later patch it will
be used for preventing bogus warnings from the lockdep checker.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index f5adce049b35ed8351b19c15c4c2518bd86cd5b6..78e910b2046c6516b12f34965f3b044dbc1feebd 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2414,6 +2414,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
                usb_set_device_state(udev, USB_STATE_POWERED);
                udev->speed = USB_SPEED_UNKNOWN;
                udev->bus_mA = hub->mA_per_port;
+               udev->level = hdev->level + 1;
 
                /* set the address */
                choose_address(udev);

diff --git a/include/linux/usb.h b/include/linux/usb.h
index c66303285a4570e64fc9f10d1cde3c586e382fd9..df5c93eb3ce9cc1336b75bd44dcae67107df1fbf 100644 (file)
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -348,6 +348,7 @@ struct usb_device {
 
        unsigned short bus_mA;          /* Current available from the bus */
        u8 portnum;                     /* Parent port number (origin 1) */
+       u8 level;                       /* Number of USB hub ancestors */
 
        int have_langid;                /* whether string_langid is valid */
        int string_langid;              /* language ID for strings */