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

[Stefano Garzarella <sgarzare@redhat.com>]

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@intel.com>
>---
> 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