Re: [bug] ata subsystem related crash with latest -git

Arjan van de Ven
2007-10-18T17:13:41Z

On Thu, 18 Oct 2007 09:55:04 -0700 (PDT)
Linus Torvalds <torvalds@linux-foundation.org> wrote:

>
>
> On Thu, 18 Oct 2007, Jens Axboe wrote:
> > - unsigned long addr = page_to_phys(s->page) +
> > s->offset;
> > + unsigned long addr = page_to_phys(sg_page(s)) +
> > s->offset;
>
> Umm. May I suggest (I haven't read the whole thread yet, maybe
> somebody else already did) that
>
> static inline unsigned long sg_phys(struct scatterlist *sg)
> {
> return page_to_phys(sg_page(sg)) + sg->offset;
> }
>
> would be a good thing to have?
>
> Very few drivers should care so much about the *page* itself (or the
> offset). That's something that the generic allocation code etc cares
> about, but the driver is almost bound to care mostly about the actual
> DMA address

.... but will that work for systems with IOMMU ? or is it fundamentally
the wrong interface