USB: add reset_resume method

This patch (as918) introduces a new USB driver method: reset_resume.
It is called when a device needs to be reset as part of a resume
procedure (whether because of a device quirk or because of the
USB-Persist facility), thereby taking over a role formerly assigned to
the post_reset method.  As a consequence, post_reset no longer needs
an argument indicating whether it is being called as part of a
reset-resume.  This separation of functions makes the code clearer.

In addition, the pre_reset and post_reset method return types are
changed; they now must return an error code.  The return value is
unused at present, but at some later time we may unbind drivers and
re-probe if they encounter an error during reset handling.

The existing pre_reset and post_reset methods in the usbhid,
usb-storage, and hub drivers are updated to match the new
requirements.  For usbhid the post_reset routine is also used for
reset_resume (duplicate method pointers); for the other drivers a new
reset_resume routine is added.  The change to hub.c looks bigger than
it really is, because mark_children_for_reset_resume() gets moved down
next to the new hub_reset_resume() routine.

A minor change to usb-storage makes the usb_stor_report_bus_reset()
routine acquire the host lock instead of requiring the caller to hold
it already.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 5 insertions, 2 deletions

diff --git a/include/linux/usb.h b/include/linux/usb.h
index 0873c62..bde8c65 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -839,6 +839,8 @@ struct usbdrv_wrap {
  *	do (or don't) show up otherwise in the filesystem.
  * @suspend: Called when the device is going to be suspended by the system.
  * @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_composite_device() when the device
  *	is about to be reset.
  * @post_reset: Called by usb_reset_composite_device() after the device
@@ -885,9 +887,10 @@ struct usb_driver {
 
 	int (*suspend) (struct usb_interface *intf, pm_message_t message);
 	int (*resume) (struct usb_interface *intf);
+	int (*reset_resume)(struct usb_interface *intf);
 
-	void (*pre_reset) (struct usb_interface *intf);
-	void (*post_reset) (struct usb_interface *intf, int reset_resume);
+	int (*pre_reset)(struct usb_interface *intf);
+	int (*post_reset)(struct usb_interface *intf);
 
 	const struct usb_device_id *id_table;