Re: i82544EI ethernet driver

[Kate Feng <feng1%bnl.gov@localhost>]

Allen Briggs wrote:

> On Mon, Nov 15, 2004 at 02:28:48PM -0500, Kate Feng wrote:
> > I am porting it to  a big-endian PowerPC.   Thus,
> > 1) for data buffer,  I  think I  should add :
> >
> >   sc->sc_ctrl |= CTRL_BEM;
> >
> > prio to
> >
> >   /* Write the control registers. */
> >   CSR_WRITE(WMREG_CTRL, sc->sc_ctrl);
> >
> >
> > 2) for the descriptor,  I should keep the original
> > codes  htole32/le32toh, and le16toh....
> > Meanwhile, I should  do
> >
> > #define BYTE_ORDER    BIG_ENDIAN
> >
> >
> > Is  that right ?
>
> I would try to get it working as-is first.

You mentioned the code was tested for both big-endian and
little-endian.  It must be somewhere I have to do
#define BYTE_ORDER BIG_ENDIAN

Does that make sense ?

Thanks,
Kate

> You should not need to
> modify the driver to get it to work.  Your bus_space routines for
> the bus should take care of any CPU->PCI byte swapping and since
> the chip is, by default, using little-endian, it will expect the
> descriptors in memory to be little-endian (so you need to write
> them with htole32 and friends, then read them with le32toh and
> friends).  Does that make sense?
>
> -allen
>
> --
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