Re: [RFC/T] [NET] make pskb_expand_head warn when called with invalid state

David Miller
2008-05-13T08:38:08Z

From: Johannes Berg <johannes@sipsolutions.net>
Date: Tue, 13 May 2008 10:32:08 +0200

> > FWIW, the only practical case where this can occur is for an SG+CSUM
> > device which cannot handle DMA'ing highmem pages, and we get such a
> > page via sendfile() or similar.
>
> That's well possible since I'm using sungem and it says "no highdma" but
> "sg/hwcsum" for my hardware, and I do have highmem.

It appears only some sungem parts support full 64-bit DMA, so
yes that's indeed possible.