From 716fdee110ceb816cca8c46c0890d08c5a1addb9 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Tue, 29 Sep 2009 21:07:19 -0300 Subject: V4L/DVB (13152): uvcvideo: Rely on videodev to reference-count the device The uvcvideo driver has a driver-wide lock and a reference count to protect against a disconnect/open race. Now that videodev handles the race itself, reference-counting in the driver can be removed. Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/uvc/uvc_v4l2.c | 32 ++++++++------------------------ 1 file changed, 8 insertions(+), 24 deletions(-) (limited to 'drivers/media/video/uvc/uvc_v4l2.c') diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c index 94c1d6696af5..b3478d0eaf41 100644 --- a/drivers/media/video/uvc/uvc_v4l2.c +++ b/drivers/media/video/uvc/uvc_v4l2.c @@ -376,25 +376,18 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream, */ static int uvc_acquire_privileges(struct uvc_fh *handle) { - int ret = 0; - /* Always succeed if the handle is already privileged. */ if (handle->state == UVC_HANDLE_ACTIVE) return 0; /* Check if the device already has a privileged handle. */ - mutex_lock(&uvc_driver.open_mutex); if (atomic_inc_return(&handle->stream->active) != 1) { atomic_dec(&handle->stream->active); - ret = -EBUSY; - goto done; + return -EBUSY; } handle->state = UVC_HANDLE_ACTIVE; - -done: - mutex_unlock(&uvc_driver.open_mutex); - return ret; + return 0; } static void uvc_dismiss_privileges(struct uvc_fh *handle) @@ -421,24 +414,20 @@ static int uvc_v4l2_open(struct file *file) int ret = 0; uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_open\n"); - mutex_lock(&uvc_driver.open_mutex); stream = video_drvdata(file); - if (stream->dev->state & UVC_DEV_DISCONNECTED) { - ret = -ENODEV; - goto done; - } + if (stream->dev->state & UVC_DEV_DISCONNECTED) + return -ENODEV; ret = usb_autopm_get_interface(stream->dev->intf); if (ret < 0) - goto done; + return ret; /* Create the device handle. */ handle = kzalloc(sizeof *handle, GFP_KERNEL); if (handle == NULL) { usb_autopm_put_interface(stream->dev->intf); - ret = -ENOMEM; - goto done; + return -ENOMEM; } if (atomic_inc_return(&stream->dev->users) == 1) { @@ -447,7 +436,7 @@ static int uvc_v4l2_open(struct file *file) usb_autopm_put_interface(stream->dev->intf); atomic_dec(&stream->dev->users); kfree(handle); - goto done; + return ret; } } @@ -456,11 +445,7 @@ static int uvc_v4l2_open(struct file *file) handle->state = UVC_HANDLE_PASSIVE; file->private_data = handle; - kref_get(&stream->dev->kref); - -done: - mutex_unlock(&uvc_driver.open_mutex); - return ret; + return 0; } static int uvc_v4l2_release(struct file *file) @@ -490,7 +475,6 @@ static int uvc_v4l2_release(struct file *file) uvc_status_stop(stream->dev); usb_autopm_put_interface(stream->dev->intf); - kref_put(&stream->dev->kref, uvc_delete); return 0; } -- cgit v1.2.1