Re: [PATCH v2] staging: most: video: prevent probes during component exit

[Dan Carpenter <dan.carpenter@linaro.org>]

On Wed, Nov 26, 2025 at 10:59:10AM -0500, Pavan Kumar Yalagada wrote:
> @@ -453,6 +455,9 @@ static int comp_probe_channel(struct most_interface *iface, int channel_idx,
>  			      struct most_channel_config *ccfg, char *name,
>  			      char *args)
>  {
> +	if (comp_exiting)
> +		return -EBUSY;
> +
>  	int ret;
>  	struct most_video_dev *mdev = get_comp_dev(iface, channel_idx);

You've added this check above the declaration block which is ugly.

But what would happen if comp_exiting is false when we check here but
it's true by the time we get to the line which says:

	list_add(&mdev->list, &video_devices);

There would still be a race.

>  
> @@ -553,6 +558,7 @@ static int __init comp_init(void)
>  
>  static void __exit comp_exit(void)
>  {
> +	comp_exiting = true;
>  	struct most_video_dev *mdev, *tmp;

In front of the declaration block.

>  
>  	/*
> @@ -575,7 +581,7 @@ static void __exit comp_exit(void)
>  
>  	most_deregister_configfs_subsys(&comp);
>  	most_deregister_component(&comp);
> -	BUG_ON(!list_empty(&video_devices));
> +	WARN_ON_ONCE(!list_empty(&video_devices));

When the race condition is fixed, then we can just remove this.

regards,
dan carpenter