[U-Boot-Users] TSEC Ethernet driver patch - RFC

Andy Fleming
2008-01-15T16:56:21Z

On Jan 9, 2008 2:26 PM, <michael.firth@bt.com> wrote:
>

> > michael.firth at bt.com wrote:
> > > While debugging a board recently I found that the MDIO
> > (mii) command
> > > support in the TSEC Ethernet driver is somewhat unhelpful.
> > >
> > > Currently, even though there is a comment in the code that
> > "For now,
> > > only TSEC1 (index 0) has access to the PHYs, so all of the entries
> > > have '0'", all MDIO commands are processed by searching for a TSEC
> > > instance that has the requested MDIO address associated
> > with it, and
> > > then using that instance to run the command, even though,
> > because of
> > > the aforementioned comment, all instances process MDIO commands
> > > through the same port.
> > >

So, for the most part, I'm happy with this change. I suspect that I
over-engineered it, originally, anticipating the possibility that a
future part might make use of the other mdio interfaces.

The biggest problem I see is that the TBI PHYs, which are internal to
each TSEC, are accessed through the other mdio interfaces. Right now
this isn't really supported, but there's a desire to expose these,
since they are used for SGMII configuration. I hadn't yet figured out
the best way to do that, but this change would potentially make it
more difficult.

Ideally, we would stop referring to PHYs only by address on the bus.
There could be multiple busses (and, in fact, there are), so the ideal
solution would deal with that. But that's a hefty task (which I'm
hoping Ben finds time for), so I'm not really suggesting that for the
short term. For now it's probably fine as long as it doesn't make
Ben's job harder. But it's not really changing the higher-level
interface, so that should be ok, too.

Andy