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author | Alan Stern <stern@rowland.harvard.edu> | 2012-01-24 19:34:24 +0100 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2012-01-25 01:00:34 +0100 |
commit | fde25a9b63b9a3dc91365c394a426ebe64cfc2da (patch) | |
tree | ecc24bd2702cb7cb32cd4d22729541d5c79cee39 /drivers/media/video/s5p-fimc | |
parent | driver-core: Fix possible null reference in subsys_interface_unregister (diff) | |
download | linux-fde25a9b63b9a3dc91365c394a426ebe64cfc2da.tar.xz linux-fde25a9b63b9a3dc91365c394a426ebe64cfc2da.zip |
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>
Diffstat (limited to 'drivers/media/video/s5p-fimc')
-rw-r--r-- | drivers/media/video/s5p-fimc/fimc-mdevice.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/drivers/media/video/s5p-fimc/fimc-mdevice.c b/drivers/media/video/s5p-fimc/fimc-mdevice.c index 8ea4ee116e46..63eccb55728f 100644 --- a/drivers/media/video/s5p-fimc/fimc-mdevice.c +++ b/drivers/media/video/s5p-fimc/fimc-mdevice.c @@ -344,16 +344,13 @@ static int fimc_md_register_platform_entities(struct fimc_md *fmd) return -ENODEV; ret = driver_for_each_device(driver, NULL, fmd, fimc_register_callback); - put_driver(driver); if (ret) return ret; driver = driver_find(CSIS_DRIVER_NAME, &platform_bus_type); - if (driver) { + if (driver) ret = driver_for_each_device(driver, NULL, fmd, csis_register_callback); - put_driver(driver); - } return ret; } |