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authorHans Verkuil2010-10-17 09:26:18 -0300
committerMauro Carvalho Chehab2010-10-22 23:40:58 -0200
commita682d4cb768381039bdafdc3c04c53cf8d70dcf0 (patch)
tree5b4b92be483f34d08b85e25ae7938af416bc7316 /drivers/media
parente2302501c32a0e7e34b7077f10da03b72dd91570 (diff)
[media] [RFC] radio-mr800: locking fixes
- serialize the suspend and resume functions using the global lock. - do not call usb_autopm_put_interface after a disconnect. - fix a race when disconnecting the device. Reported-by: David Ellingsworth <david@identd.dyndns.org> Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Acked-by: David Ellingsworth<david@identd.dyndns.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/radio/radio-mr800.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/media/radio/radio-mr800.c b/drivers/media/radio/radio-mr800.c
index 2f56b26cece9..b540e8072e92 100644
--- a/drivers/media/radio/radio-mr800.c
+++ b/drivers/media/radio/radio-mr800.c
@@ -284,9 +284,13 @@ static void usb_amradio_disconnect(struct usb_interface *intf)
struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf));
mutex_lock(&radio->lock);
+ /* increase the device node's refcount */
+ get_device(&radio->videodev.dev);
v4l2_device_disconnect(&radio->v4l2_dev);
- mutex_unlock(&radio->lock);
video_unregister_device(&radio->videodev);
+ mutex_unlock(&radio->lock);
+ /* decrease the device node's refcount, allowing it to be released */
+ put_device(&radio->videodev.dev);
}
/* vidioc_querycap - query device capabilities */
@@ -515,7 +519,8 @@ static int usb_amradio_close(struct file *file)
{
struct amradio_device *radio = file->private_data;
- usb_autopm_put_interface(radio->intf);
+ if (video_is_registered(&radio->videodev))
+ usb_autopm_put_interface(radio->intf);
return 0;
}
@@ -524,10 +529,12 @@ static int usb_amradio_suspend(struct usb_interface *intf, pm_message_t message)
{
struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf));
+ mutex_lock(&radio->lock);
if (!radio->muted && radio->initialized) {
amradio_set_mute(radio, AMRADIO_STOP);
radio->muted = 0;
}
+ mutex_unlock(&radio->lock);
dev_info(&intf->dev, "going into suspend..\n");
return 0;
@@ -538,8 +545,9 @@ static int usb_amradio_resume(struct usb_interface *intf)
{
struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf));
+ mutex_lock(&radio->lock);
if (unlikely(!radio->initialized))
- return 0;
+ goto unlock;
if (radio->stereo)
amradio_set_stereo(radio, WANT_STEREO);
@@ -551,6 +559,9 @@ static int usb_amradio_resume(struct usb_interface *intf)
if (!radio->muted)
amradio_set_mute(radio, AMRADIO_START);
+unlock:
+ mutex_unlock(&radio->lock);
+
dev_info(&intf->dev, "coming out of suspend..\n");
return 0;
}