Driver core: driver_find() drops reference before returning

As part of the removal of get_driver()/put_driver(), this patch
(as1510) changes driver_find(); it now drops the reference it acquires
before returning.  The patch also adjusts all the callers of
driver_find() to remove the now unnecessary calls to put_driver().

In addition, the patch adds a warning to driver_find(): Callers must
make sure the driver they are searching for does not get unloaded
while they are using it.  This has always been the case; driver_find()
has never prevented a driver from being unregistered or unloaded.
Hence the patch will not introduce any new bugs.  The existing callers
all seem to be okay in this respect, however I don't understand the
video drivers well enough to be certain about them.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
CC: Kyungmin Park <kyungmin.park@samsung.com>
CC: Andy Walls <awalls@md.metrocast.net>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern
2012-01-24 13:34:24 -05:00
committed by Greg Kroah-Hartman
parent 2b31594a95
commit fde25a9b63
8 changed files with 10 additions and 17 deletions
-1
View File
@@ -441,7 +441,6 @@ static ssize_t serio_rebind_driver(struct device *dev, struct device_attribute *
} else if ((drv = driver_find(buf, &serio_bus)) != NULL) {
serio_disconnect_port(serio);
error = serio_bind_driver(serio, to_serio_driver(drv));
put_driver(drv);
serio_remove_duplicate_events(serio, SERIO_RESCAN_PORT);
} else {
error = -EINVAL;