Greg Ungerer [off-list ref] writes:
The built in ethernet interfaces on the ixp4xx family are not PCI
based. So they at least do not suffer from the BE/LE conversions
at the eth driver.
The problematic one is IXP42x rev. A0. It has no support for hw mixed
mode (LE core + lane swapping where needed). Unfortunately this early
chip is quite popular. "Software" mixed mode means byte swapping in the
network drivers and IIRC the crypto accelerator becomes unusable (at
least without workarounds).
Later revisions (42x rev. B0 and up, and all other IXP4[356]) can work
in the most efficient hw mixed mode. Support is not upstream but it's
basically ready. I think it may be incompatible with XIP.
--
Krzysztof Halasa