From fde25a9b63b9a3dc91365c394a426ebe64cfc2da Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 24 Jan 2012 13:34:24 -0500 Subject: 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 CC: Dmitry Torokhov CC: Kyungmin Park CC: Andy Walls CC: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- drivers/media/video/cx18/cx18-alsa-main.c | 1 - drivers/media/video/ivtv/ivtvfb.c | 2 -- drivers/media/video/s5p-fimc/fimc-mdevice.c | 5 +---- drivers/media/video/s5p-tv/mixer_video.c | 1 - 4 files changed, 1 insertion(+), 8 deletions(-) (limited to 'drivers/media/video') diff --git a/drivers/media/video/cx18/cx18-alsa-main.c b/drivers/media/video/cx18/cx18-alsa-main.c index a1e6c2a32478..e118361c2e7b 100644 --- a/drivers/media/video/cx18/cx18-alsa-main.c +++ b/drivers/media/video/cx18/cx18-alsa-main.c @@ -285,7 +285,6 @@ static void __exit cx18_alsa_exit(void) drv = driver_find("cx18", &pci_bus_type); ret = driver_for_each_device(drv, NULL, NULL, cx18_alsa_exit_callback); - put_driver(drv); cx18_ext_init = NULL; printk(KERN_INFO "cx18-alsa: module unload complete\n"); diff --git a/drivers/media/video/ivtv/ivtvfb.c b/drivers/media/video/ivtv/ivtvfb.c index d0fbfcf7133d..e5e7fa9e737b 100644 --- a/drivers/media/video/ivtv/ivtvfb.c +++ b/drivers/media/video/ivtv/ivtvfb.c @@ -1293,7 +1293,6 @@ static int __init ivtvfb_init(void) drv = driver_find("ivtv", &pci_bus_type); err = driver_for_each_device(drv, NULL, ®istered, ivtvfb_callback_init); - put_driver(drv); if (!registered) { printk(KERN_ERR "ivtvfb: no cards found\n"); return -ENODEV; @@ -1310,7 +1309,6 @@ static void ivtvfb_cleanup(void) drv = driver_find("ivtv", &pci_bus_type); err = driver_for_each_device(drv, NULL, NULL, ivtvfb_callback_cleanup); - put_driver(drv); } module_init(ivtvfb_init); 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; } diff --git a/drivers/media/video/s5p-tv/mixer_video.c b/drivers/media/video/s5p-tv/mixer_video.c index 7884baeff76a..f7ca5cc143c6 100644 --- a/drivers/media/video/s5p-tv/mixer_video.c +++ b/drivers/media/video/s5p-tv/mixer_video.c @@ -58,7 +58,6 @@ static struct v4l2_subdev *find_and_register_subdev( } done: - put_driver(drv); return sd; } -- cgit v1.2.3