[U-Boot] FW: ARM Pull Request

Lennert Buytenhek
2009-07-23T08:49:27Z

On Wed, Jul 22, 2009 at 11:44:57PM -0700, Prafulla Wadaskar wrote:

> > >Isn't it just because on the RD6281A, the first ethernet MAC of the
> > >CPU is connected to an ethernet switch chip instead of an
> > ethernet PHY,
> > >and therefore there is no negotiation to be done?
>
> But auto negotiation works with other board for similar case (i.e.
> mv88f6281gtw_ge)
> Only the difference is on rd6281A multichip addressing mode is used.
> I cannot comment much on this at this moment, this is my observation.
> So I was planning to debug this part.

In single-chip address mode, you'll still only be talking to one of
the five PHYs that the switch chip has, and things like forcing link
modes or checking whether the link is up will only work on one of
the five ports.

So if you're checking the PHY registers to make sure the link is up
before you e.g. start sending DHCP requests, then that won't do what
you want even though it will appear to work in single-chip address
mode.

If you're providing a way to force certain ports to certain speeds
from the uboot command line, then you should ideally just implement
multi-chip addressing mode and allow access to the individual PHYs,
I guess.