Re: [PATCH 2/2] vfio/mdev: don't warn if ->request is not set

[Cornelia Huck <cohuck@redhat.com>]

On Mon, Jul 26 2021, Christoph Hellwig <hch@lst.de> wrote:

> Only a single driver actually sets the ->request method, so don't print
> a scary warning if it isn't.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/vfio/mdev/mdev_core.c | 4 ----
>  1 file changed, 4 deletions(-)
>
> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
> index b16606ebafa1..b314101237fe 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -138,10 +138,6 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
>  	if (!dev)
>  		return -EINVAL;
>  
> -	/* Not mandatory, but its absence could be a problem */
> -	if (!ops->request)
> -		dev_info(dev, "Driver cannot be asked to release device\n");
> -
>  	mutex_lock(&parent_list_lock);
>  
>  	/* Check for duplicate */

We also log a warning if we would like to call ->request() but none was
provided, so I think that's fine.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>

But I wonder why nobody else implements this? Lack of surprise removal?