Re: Custom device names for v4l2 devices

[vkalia@codeaurora.org]

Please suggest.

Thanks
Vinay

> Hi
>
> Names of V4L2 device nodes keep on varying depending on target, on some
> targets, the device node assigned to my device is /dev/video21 and on some
> it is /dev/video15. In order to determine my device, i am opening it,
> reading the capabilities, enumerating its formats and then chose the one
> matching my requirements. This is impacting start-up latency. One way to
> resolve this without impacting start-up latency is to give custom name to
> my V4L2 device node (/dev/custom_name instead of /dev/video21). This needs
> following change in V4L2 framework. Please review this patch. If you have
> faced similar problem please let me know.
>
> --- a/drivers/media/video/v4l2-dev.c
> +++ b/drivers/media/video/v4l2-dev.c
> @@ -676,7 +676,8 @@ int __video_register_device(struct video_device *vdev,
> int type, int nr,
>  	vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor);
>  	if (vdev->parent)
>  		vdev->dev.parent = vdev->parent;
> -	dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num);
> +	if (!dev_name(&vdev->dev))
> +		dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num);
>  	ret = device_register(&vdev->dev);
>  	if (ret < 0) {
>  		printk(KERN_ERR "%s: device_register failed\n", __func__);
>
>
> Thanks
> Vinay
>