Re: [PATCH v3 net] i40e: Look up MAC address in Open Firmware or IDPROM

From: Sowmini Varadhan
Date: Sun Nov 01 2015 - 11:24:19 EST


On (10/30/15 19:13), Sowmini Varadhan wrote:
> > In looking at a couple other drivers, I see the difference being that
> > they typically are writing the primary mac filter on probe (and any
> > other reset), whereas the i40e "knows" that the default mac address is
> > already set up as the filter and doesn't bother with a redundant write.
> > If you want to add this Open Filter code, you'll need to arrange for
> > this write to happen. You can't call i40e_set_mac() to do it, but you
> > can see the i40e_aq_mac_address_write() code there that is involved in
> > updating the mac address as an example. You probably will want to look
> > at section 4.2.1.5.3 of the XL710 data sheet in order to know how to
> > use i40e_aq_mac_address_write() for your situation.
>
> ok. I'll look into it (and also why this did not show up in my testing).

So I figured out why it all "seemed to work" - my test env had another
obscure init process that was marking the link promiscuous. I guess
that was having the side-effect of somehow setting the filters above.

But looks like there's more to getting this right than just calling
i40e_aq_mac_address_write() - I think it also needs a i40e_aq_add_macvlan().

I was able to get this to work by calling a the core part of
i40e_set_mac just before register_netdev. In my patch (RFC patch
in a separate thread - please review) I now have this sequence in
i40e_probe

err = i40e_get_platform_mac_addr(pdev, hw->mac.addr);
if (err)
i40e_get_mac_addr(hw, hw->mac.addr);
:
i40e_setup_pf_switch(..);

And the resulting i40e_vsi_setup() from i40e_setup_pf_switch()
will end up doing the right thing by invoking the guts of
i40e_set_mac(), which is basically the sequence:
i40e_aq_mac_address_write()
i40e_aq_add_macvlan()

I dont know if it is necessary/possible/important to set up the
filters sooner in the sequence- the add_macvlan needs an "seid",
and I could not tell when (in the ":" code above) the right seid
can be found.

Please review the RFC patch I'll be sending shortly.

--Sowmini

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