USB: remove use of the bus rwsem, as it doesn't really protect anything.

The driver core stopped using the rwsem a long time ago, yet the USB
core still grabbed the lock, thinking it protected something.  This
patch removes that useless use.

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oneukum@suse.de>
Cc: David Brownell <david-b@pacbell.net>
Cc: linux-usb-devel <linux-usb-devel@lists.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 0 insertions, 2 deletions

diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
index aefc7987120d..6753ca059ee4 100644
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -246,7 +246,6 @@ static char *usb_dump_interface_descriptor(char *start, char *end,
 
         if (start > end)
                 return start;
-        down_read(&usb_bus_type.subsys.rwsem);
         if (iface) {
                 driver_name = (iface->dev.driver
                                 ? iface->dev.driver->name
@@ -263,7 +262,6 @@ static char *usb_dump_interface_descriptor(char *start, char *end,
                          desc->bInterfaceSubClass,
                          desc->bInterfaceProtocol,
                          driver_name);
-        up_read(&usb_bus_type.subsys.rwsem);
         return start;
 }