On Wednesday 18 November 2009 01:38:45 Laurent Pinchart wrote:
> Replace the video_is_unregistered function by a video_is_registered
> function. The V4L2_FL_UNREGISTERED flag is replaced by a
> V4L2_FL_REGISTERED flag.
>
> This change makes the video_is_registered function return coherent
> results when called on an initialize but not yet registered video_device
> instance. The function can now be used instead of checking
> video_device::minor.
Much better than what I wrote originally! I like this!
Regards,
Hans
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Index: v4l-dvb-mc-uvc/linux/drivers/media/video/v4l2-dev.c
> ===================================================================
> --- v4l-dvb-mc-uvc.orig/linux/drivers/media/video/v4l2-dev.c
> +++ v4l-dvb-mc-uvc/linux/drivers/media/video/v4l2-dev.c
> @@ -227,7 +227,7 @@ static ssize_t v4l2_read(struct file *fi
>
> if (!vdev->fops->read)
> return -EINVAL;
> - if (video_is_unregistered(vdev))
> + if (!video_is_registered(vdev))
> return -EIO;
> return vdev->fops->read(filp, buf, sz, off);
> }
> @@ -239,7 +239,7 @@ static ssize_t v4l2_write(struct file *f
>
> if (!vdev->fops->write)
> return -EINVAL;
> - if (video_is_unregistered(vdev))
> + if (!video_is_registered(vdev))
> return -EIO;
> return vdev->fops->write(filp, buf, sz, off);
> }
> @@ -248,7 +248,7 @@ static unsigned int v4l2_poll(struct fil
> {
> struct video_device *vdev = video_devdata(filp);
>
> - if (!vdev->fops->poll || video_is_unregistered(vdev))
> + if (!vdev->fops->poll || !video_is_registered(vdev))
> return DEFAULT_POLLMASK;
> return vdev->fops->poll(filp, poll);
> }
> @@ -288,7 +288,7 @@ static unsigned long v4l2_get_unmapped_a
>
> if (!vdev->fops->get_unmapped_area)
> return -ENOSYS;
> - if (video_is_unregistered(vdev))
> + if (!video_is_registered(vdev))
> return -ENODEV;
> return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
> }
> @@ -298,8 +298,7 @@ static int v4l2_mmap(struct file *filp,
> {
> struct video_device *vdev = video_devdata(filp);
>
> - if (!vdev->fops->mmap ||
> - video_is_unregistered(vdev))
> + if (!vdev->fops->mmap || !video_is_registered(vdev))
> return -ENODEV;
> return vdev->fops->mmap(filp, vm);
> }
> @@ -315,7 +314,7 @@ static int v4l2_open(struct inode *inode
> vdev = video_devdata(filp);
> /* return ENODEV if the video device has been removed
> already or if it is not registered anymore. */
> - if (vdev == NULL || video_is_unregistered(vdev)) {
> + if (vdev == NULL || !video_is_registered(vdev)) {
> mutex_unlock(&videodev_lock);
> return -ENODEV;
> }
> @@ -623,6 +622,7 @@ static int __video_register_device(struc
> name_base, nr, video_device_node_name(vdev));
>
> /* Part 5: Activate this minor. The char device can now be used. */
> + set_bit(V4L2_FL_REGISTERED, &vdev->flags);
> mutex_lock(&videodev_lock);
> video_device[vdev->minor] = vdev;
> mutex_unlock(&videodev_lock);
> @@ -661,11 +661,11 @@ EXPORT_SYMBOL(video_register_device_no_w
> void video_unregister_device(struct video_device *vdev)
> {
> /* Check if vdev was ever registered at all */
> - if (!vdev || vdev->minor < 0)
> + if (!vdev || !video_is_registered(vdev))
> return;
>
> mutex_lock(&videodev_lock);
> - set_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
> + clear_bit(V4L2_FL_REGISTERED, &vdev->flags);
> mutex_unlock(&videodev_lock);
> #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19)
> class_device_unregister(&vdev->dev);
> Index: v4l-dvb-mc-uvc/linux/include/media/v4l2-dev.h
> ===================================================================
> --- v4l-dvb-mc-uvc.orig/linux/include/media/v4l2-dev.h
> +++ v4l-dvb-mc-uvc/linux/include/media/v4l2-dev.h
> @@ -28,10 +28,10 @@ struct v4l2_ioctl_callbacks;
> struct video_device;
> struct v4l2_device;
>
> -/* Flag to mark the video_device struct as unregistered.
> - Drivers can set this flag if they want to block all future
> - device access. It is set by video_unregister_device. */
> -#define V4L2_FL_UNREGISTERED (0)
> +/* Flag to mark the video_device struct as registered.
> + Drivers can clear this flag if they want to block all future
> + device access. It is cleared by video_unregister_device. */
> +#define V4L2_FL_REGISTERED (0)
>
> struct v4l2_file_operations {
> struct module *owner;
> @@ -100,9 +100,7 @@ struct video_device
> /* Register video devices. Note that if video_register_device fails,
> the release() callback of the video_device structure is *not* called, so
> the caller is responsible for freeing any data. Usually that means that
> - you call video_device_release() on failure.
> -
> - Also note that vdev->minor is set to -1 if the registration failed. */
> + you call video_device_release() on failure. */
> int __must_check video_register_device(struct video_device *vdev, int type, int nr);
>
> /* Same as video_register_device, but no warning is issued if the desired
> @@ -110,7 +108,7 @@ int __must_check video_register_device(s
> int __must_check video_register_device_no_warn(struct video_device *vdev, int type, int nr);
>
> /* Unregister video devices. Will do nothing if vdev == NULL or
> - vdev->minor < 0. */
> + video_is_registered() returns false. */
> void video_unregister_device(struct video_device *vdev);
>
> /* helper functions to alloc/release struct video_device, the
> @@ -162,9 +160,9 @@ static inline const char *video_device_n
> #endif
> }
>
> -static inline int video_is_unregistered(struct video_device *vdev)
> +static inline int video_is_registered(struct video_device *vdev)
> {
> - return test_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
> + return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
> }
>
> #endif /* _V4L2_DEV_H */
>
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG Telecom
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