IEEE1394: remove rwsem use from ieee1394 core

The subsystem rwsem is not used by the driver core at all, so the use of
it in the ieee1394 code doesn't make any sense.  They might possibly
want to use a local lock, but as most of these operations are already
protected by a local lock, it really doesn't look like it would be
needed.

Cc: Ben Collins <bcollins@debian.org>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: linux1394-devel <linux1394-devel@lists.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/ieee1394/nodemgr.c

@@ -370,9 +370,7 @@ static ssize_t fw_set_ignore_driver(struct device *dev, struct device_attribute
 
 	if (state == 1) {
 		ud->ignore_driver = 1;
-		down_write(&ieee1394_bus_type.subsys.rwsem);
 		device_release_driver(dev);
-		up_write(&ieee1394_bus_type.subsys.rwsem);
 	} else if (state == 0)
 		ud->ignore_driver = 0;
 
@@ -1391,12 +1389,10 @@ static void nodemgr_suspend_ne(struct node_entry *ne)
 		if (ud->ne != ne)
 			continue;
 
-		down_write(&ieee1394_bus_type.subsys.rwsem);
 		if (ud->device.driver &&
 		    (!ud->device.driver->suspend ||
 		      ud->device.driver->suspend(&ud->device, PMSG_SUSPEND)))
 			device_release_driver(&ud->device);
-		up_write(&ieee1394_bus_type.subsys.rwsem);
 	}
 	up(&nodemgr_ud_class.sem);
 }
@@ -1416,10 +1412,8 @@ static void nodemgr_resume_ne(struct node_entry *ne)
 		if (ud->ne != ne)
 			continue;
 
-		down_read(&ieee1394_bus_type.subsys.rwsem);
 		if (ud->device.driver && ud->device.driver->resume)
 			ud->device.driver->resume(&ud->device);
-		up_read(&ieee1394_bus_type.subsys.rwsem);
 	}
 	up(&nodemgr_ud_class.sem);
 
@@ -1440,7 +1434,6 @@ static void nodemgr_update_pdrv(struct node_entry *ne)
 		if (ud->ne != ne)
 			continue;
 
-		down_write(&ieee1394_bus_type.subsys.rwsem);
 		if (ud->device.driver) {
 			pdrv = container_of(ud->device.driver,
 					    struct hpsb_protocol_driver,
@@ -1448,7 +1441,6 @@ static void nodemgr_update_pdrv(struct node_entry *ne)
 			if (pdrv->update && pdrv->update(ud))
 				device_release_driver(&ud->device);
 		}
-		up_write(&ieee1394_bus_type.subsys.rwsem);
 	}
 	up(&nodemgr_ud_class.sem);
 }