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

[Jens Axboe <jens.axboe@oracle.com>]

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