Re: sky2: hw checksum failures

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

> > Which means that if it worked on x86 with le16_to_cpu, it should work on
> > powerpc... The main difference here however is that you called
> > le16_to_cpu (which is basically a nop) on a 32 bits field, while I
> > called le32_to_cpu() on it. But both should lead to the same ... (x86
> > will do a swapped 16 bits load of the 2 first bytes, while ppc will do a
> > load of 4 bytes and swap that, thus ending up with the first 2 bytes
> > swapped in the low order of the result). I'll dump the values and have a
> > look to be sure. Another possibility would be a problem with the bits
> > telling the chip where to calculate the checksum.
> >   
> Hardware only computes 16 bit checksum.

Oh I know that, but calling 16 bits swapping macros on a 32 bits field
is a bit dodgy... might work in this case, I'll verify, but you may end
up with the wrong half of the 32 bits word being used :)

Ben.