USB: documentation update for the pre_reset method
This patch (as1459) updates the documentation for the pre_reset method
in struct usb_driver. When a driver is notified of an impending
reset, it must cancel all outstanding I/O and not start any new I/O
until it has been notified that the reset is complete.
As far as I know, most existing drivers that implement pre_reset do
this now. The major exceptions appear to be the SpeedTouch and
CDC-WDM drivers.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 65f78ca..73c7df4 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -806,8 +806,10 @@
* @resume: Called when the device is being resumed by the system.
* @reset_resume: Called when the suspended device has been reset instead
* of being resumed.
- * @pre_reset: Called by usb_reset_device() when the device
- * is about to be reset.
+ * @pre_reset: Called by usb_reset_device() when the device is about to be
+ * reset. This routine must not return until the driver has no active
+ * URBs for the device, and no more URBs may be submitted until the
+ * post_reset method is called.
* @post_reset: Called by usb_reset_device() after the device
* has been reset
* @id_table: USB drivers use ID table to support hotplugging.