[dpdk-dev] [PATCH v2] i40e: modify the meaning of single VLAN type

[Panu Matilainen]

On 06/21/2016 01:29 PM, Bruce Richardson wrote:
> On Mon, Jun 13, 2016 at 04:03:32PM +0800, Beilei Xing wrote:
>> In current i40e codebase, if single VLAN header is added in a packet,
>> it's treated as inner VLAN. Generally, a single VLAN header is
>> treated as the outer VLAN header. So change corresponding register
>> for single VLAN.
>> At the meanwhile, change the meanings of inner VLAN and outer VLAN.
>>
>> Signed-off-by: Beilei Xing <beilei.xing at intel.com>
>
> This patch changes the ABI, since an app written to the original API as specified
> e.g. to set a single vlan header, would no longer work with this change.
> Therefore, even though the original behaviour was inconsistent with other drivers
> it may still need to be preserved.
>
> I'm thinking that we may need to provide appropriately versioned copies of the
> vlan_offload_set and vlan_tpid_set functions for backward compatibility with
> the old ABI.
>
> Any other comments or thoughts on this?
> Neil, Thomas, Panu - is this fix something that we need to provide backward
> version-compatibility for, or given that the functions are being called through
> a generic ethdev API mean that this can just go in as a straight bug-fix?

Since it's currently inconsistent with everything else, I'd just call it 
a bug-fix and leave it at that.

Besides, I dont think you could version it via the ordinary means even 
if you wanted to, due to the way its called through eth_dev_ops etc.

	- Panu -