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>

1 files changed, 0 insertions, 1 deletions

diff --git a/drivers/input/gameport/gameport.c b/drivers/input/gameport/gameport.c
index c351aa421f8f..da739d9d1905 100644
--- a/drivers/input/gameport/gameport.c
+++ b/drivers/input/gameport/gameport.c
@@ -449,7 +449,6 @@ static ssize_t gameport_rebind_driver(struct device *dev, struct device_attribut
         } else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
                 gameport_disconnect_port(gameport);
                 error = gameport_bind_driver(gameport, to_gameport_driver(drv));
-                put_driver(drv);
         } else {
                 error = -EINVAL;
         }