[En-Nut-Discussion] at91_emac.c

[DeBaillie, Tim]

How old is the arch/arm/dev/at91_emac.c file?  It looks like it needs
some major rework.  A few examples:

* EmacStart always returns 0 which is used as a check during initialization.
* EMAC_TX_BUFFERS is configurable, but the functions used for TX and
initialization are coded to accept only 2 as a proper answer.
* Reinitialization of the interface is not done properly.
* TX errors are not checked nor handled.
* Blocking of multicast packets isn't configurable.
* Phy and MII interface needs to be much more configurable, including
a non-NRST line tied to the reset of the PHY/MII device.

Some of these issues I can resolve myself, but the "reinitialization
of the interface" requires some major work.

Tim