Hi Andrew, thank you so much for looking at this patch !

On Fri, Jan 29, 2021 at 3:36 PM Andrew Lunn [off-list ref] wrote:

So this patch appears to contain two different changes
1) You only allocate a receive buffer as big as the MTU plus overheads
2) You change the cache operations to operate on the received length.

The first change should be completely safe, and i guess, is giving
most of the benefits. The second one is where interesting things might
happen. So please split this patch into two.  If it does break, we can
git bisect, and probably end up on the second patch.

Yes, I tested this extensively on arm7, but you're right, it might behave
differently on other platforms. I will split into two, as you suggested.