[PATCH] USB: Remove USB private semaphore

This patch (as605) removes the private udev->serialize semaphore,
relying instead on the locking provided by the embedded struct device's
semaphore.  The changes are confined to the core, except that the
usb_trylock_device routine now uses the return convention of
down_trylock rather than down_read_trylock (they return opposite values
for no good reason).

A couple of other associated changes are included as well:

	Now that we aren't concerned about HCDs that avoid using the
	hcd glue layer, usb_disconnect no longer needs to acquire the
	usb_bus_lock -- that can be done by usb_remove_hcd where it
	belongs.

	Devices aren't locked over the same scope of code in
	usb_new_device and hub_port_connect_change as they used to be.
	This shouldn't cause any trouble.

Along with the preceding driver core patch, this needs a lot of testing.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
index 83e815d3cd52..55bc563a3256 100644
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -545,10 +545,10 @@ static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes, loff_t *ski
 		struct usb_device *childdev = usbdev->children[chix];
 
 		if (childdev) {
-			down(&childdev->serialize);
+			usb_lock_device(childdev);
 			ret = usb_device_dump(buffer, nbytes, skip_bytes, file_offset, childdev,
 					bus, level + 1, chix, ++cnt);
-			up(&childdev->serialize);
+			usb_unlock_device(childdev);
 			if (ret == -EFAULT)
 				return total_written;
 			total_written += ret;