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

[Zhu Lingshan <lingshan.zhu@linux.intel.com>]

On 4/15/2021 9:48 PM, Stefano Garzarella wrote:
> 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, the reason is we only have one line code after if, so 
looks like {} is unnecessary, I agree switch can clear up
code style confusions. I will add this in v3.

Thanks!
>
> Thanks,
> Stefano
>
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