[PATCH] HID read busywait fix

Make a read of a HID device block until data is available.  Without it, the
read goes into a busy-wait loop until data is available.

Cc: Greg KH <greg@kroah.com>
Acked-by: NVojtech Pavlik <vojtech@suse.cz>
Cc: Dmitry Torokhov <dtor_core@ameritech.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

drivers/usb/input/hiddev.c

@@ -317,6 +317,7 @@ static ssize_t hiddev_read(struct file * file, char __user * buffer, size_t coun
 				}
 
 				schedule();
+				set_current_state(TASK_INTERRUPTIBLE);
 			}
 
 			set_current_state(TASK_RUNNING);