Re: [PATCH V2 3/3] vDPA/ifcvf: get_config_size should return dev specific config size

[Stefano Garzarella <sgarzare@xxxxxxxxxx>]

On Thu, Apr 15, 2021 at 05:53:36PM +0800, Zhu Lingshan wrote:
> get_config_size() should return the size based on the decected
> device type.
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
> ---
> drivers/vdpa/ifcvf/ifcvf_main.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
> index cea1313b1a3f..6844c49fe1de 100644
> --- a/drivers/vdpa/ifcvf/ifcvf_main.c
> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
> @@ -347,7 +347,23 @@ static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)
>
> static size_t ifcvf_vdpa_get_config_size(struct vdpa_device *vdpa_dev)
> {
> -	return sizeof(struct virtio_net_config);
> +	struct ifcvf_adapter *adapter = vdpa_to_adapter(vdpa_dev);
> +	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
> +	struct pci_dev *pdev = adapter->pdev;
> +	size_t size;
> +
> +	if (vf->dev_type == VIRTIO_ID_NET)
> +		size = sizeof(struct virtio_net_config);
> +
> +	else if (vf->dev_type == VIRTIO_ID_BLOCK)
> +		size = sizeof(struct virtio_blk_config);
> +
> +	else {
> +		size = 0;
> +		IFCVF_ERR(pdev, "VIRTIO ID %u not supported\n", vf->dev_type);
> +	}

I slightly prefer the switch, but I don't have a strong opinion.

However, if we want to use if/else, we should follow 
`Documentation/process/coding-style.rst` line 166:
    Note that the closing brace is empty on a line of its own, **except** in
    the cases where it is followed by a continuation of the same statement,
    ie a ``while`` in a do-statement or an ``else`` in an if-statement, like

also `scripts/checkpatch.pl --strict` complains:

    CHECK: braces {} should be used on all arms of this statement
    #209: FILE: drivers/vdpa/ifcvf/ifcvf_main.c:355:
    +	if (vf->dev_type == VIRTIO_ID_NET)
    [...]
    +	else if (vf->dev_type == VIRTIO_ID_BLOCK)
    [...]
    +	else {
    [...]

    CHECK: Unbalanced braces around else statement
    #215: FILE: drivers/vdpa/ifcvf/ifcvf_main.c:361:
    +	else {

Thanks,
Stefano