[U-Boot] [PATCH] sunxi: Add support for eth1addr

[Ian Campbell]

On Thu, 2016-06-30 at 13:15 +0200, Hans de Goede wrote:
> Hi,
> 
> On 30-06-16 12:50, Ian Campbell wrote:
> > On Sun, 2016-06-26 at 13:54 +0200, Hans de Goede wrote:
> > > Currently we will already fill ethaddr with a fixed unique address
> > > based on the SoCs serial (from the sid) to make sure that boards which
> > > use the integrated emac / gmac get a fixed mac rather then a random one.
> > > 
> > > On some boards (observed on 2 tablets using sdio rtl8703as wifi chips)
> > > the wifi does not come with a fixed mac either, so also set eth1addr,
> > > so that dts files can set an ethernet1 alias to get mac-address and
> > > local-mac-address filled for dt nodes describing the wifi controller.
> > 
> > This does it unconditionally, won't having eth1addr show up for boards
> > which only have one network device (WIFI or otherwise) be potentially
> > confusing for users? i.e. lacking it would be a sign that the online
> > guide you are following might not exactly be relevant to your board, or
> > people seeing it and then wasting time trying to figure out how to use
> > the second device. Of secondary concern (since I think it is far less
> > liklely) would be confusing some software somewhere.
> > 
[...]
> This just sets eth1addr in the u-boot env,

It's this which I worried might confuse people, people who notice
eth1addr (perhaps due to tab completion on "printenv eth"?) will wonder
where the eth1 device is and/or why it is not working for them.

The rest of what you say regarding how this goes on to interact with
Linux makes sense to me, although even then having an eth1addr which
does't correspond to the MAC used by the device under Linux (because it
is burnt in and therefore eth1addr is ignored) still seems potentially
confusing to me.

I see at least some platforms use a CONFIG_HAS_ETH1 to control this. It
could also perhaps be gated on the DTB used by u-boot itself by looking
at the mac-address for the ethernet1 alias (and ethernet2 too I
suppose).

Ian.