From 9c84d89bf13b702ca0e0db5eb3880300c4bd58f4 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Mon, 11 Oct 2010 12:36:37 -0300 Subject: [PATCH] [media] radio-mr800: fix locking order Don't hold the lock before unregistering the device, since when the device is unregistered the datastruct containing the lock may be freed (if the refcount went to 0). Also fixed the framework documentation that erroneously suggested the wrong locking order as well. Reported-by: David Ellingsworth Signed-off-by: Hans Verkuil Acked-by: David Ellingsworth Signed-off-by: Mauro Carvalho Chehab --- Documentation/video4linux/v4l2-framework.txt | 2 +- drivers/media/radio/radio-mr800.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index a128e01..f22f35c 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt @@ -488,7 +488,7 @@ also waits in the code, then you should do the same to allow other processes to access the device node while the first process is waiting for something. The implementation of a hotplug disconnect should also take the lock before -calling v4l2_device_disconnect and video_unregister_device. +calling v4l2_device_disconnect. video_device registration ------------------------- diff --git a/drivers/media/radio/radio-mr800.c b/drivers/media/radio/radio-mr800.c index 97967ad3..2f56b26 100644 --- a/drivers/media/radio/radio-mr800.c +++ b/drivers/media/radio/radio-mr800.c @@ -285,8 +285,8 @@ static void usb_amradio_disconnect(struct usb_interface *intf) mutex_lock(&radio->lock); v4l2_device_disconnect(&radio->v4l2_dev); - video_unregister_device(&radio->videodev); mutex_unlock(&radio->lock); + video_unregister_device(&radio->videodev); } /* vidioc_querycap - query device capabilities */ -- 2.7.4