On Mon, 28 Feb 2005 09:12:52 -0800
Stephen Hemminger [off-list ref] wrote:

The original sk98lin attempted to receive hardware checksumming
but never actually turned it on.

Because there is a bug in the chip wherein checksums can be
miscalculated.  I forget the details, but I do remember that
you can't enable checksumming safely because of this.

In drivers/net/sk98lin/skcsum.c it mentions this:

 * Note:
 *      There is a bug in the GENESIS ASIC which may lead to wrong checksums.

I know this comment is above the send checksum routine, but I
am pretty sure the bug applies to both directions.