On 11/30/2016 07:10 AM, Andrew Lunn wrote: >> What is not really clear - what if several tagging protocols are used >> together. AFAIU, things may be more complex that simple appending of >> tags, e.g. EDSA tag can carry VLAN id inside. > > Hi Nikita > > At least for all current tagging protocols, the size of the tag is > constant. And you cannot run different tagging protocols on the same > master interface at the same time.
I am not sure if using envelope frames is entirely appropriate here, because there are existing switch tagging protocols that: - don't have a specific Ethernet type allocated (Broadcom tags, DSA) - could be appended at the end of the frame instead of pre-pended Alexander Duyck suggested a while ago that we may be able to use the headers_ops to implement the DSA tag pop/push, as well as get an appropriate MTU adjustment, can you see if that would work? > > However, i think Florian tried something funky with the SF2 and B53 > driver. He has a b53 hanging off a sf2. So i think he used nested > tagging protocols! Well, this actually did not work, because the SF2 and B53 switches essentially terminate switch tags when they ingress their switch ports, so the tag inserted by B53 ingressing into the SF2 port does not get sent all the way to the CPU hanging off the SF2... With the B53 hanging off the SF2, we essentially have to disable Broadcom tags in the B53 device, because the tag and switches were never designed to be cascaded in the first place (at least not these specific cores). -- Florian
