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

Jens Axboe
2007-10-18T17:01:41Z

On Thu, Oct 18 2007, Linus Torvalds 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?

Sure thing, it's used quite a lot.

> 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, so adding that helper function that abstracts the sg access would
> be helpful in hiding some of the cruft?

I'll add it to the mix.

--
Jens Axboe