[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: Vojtech Pavlik <vojtech@suse.cz>
Cc: Dmitry Torokhov <dtor_core@ameritech.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/drivers/usb/input/hiddev.c b/drivers/usb/input/hiddev.c
index 6dd6666..c4670e1 100644 (file)
--- a/drivers/usb/input/hiddev.c
+++ b/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);