Re: [GIT PATCH] Fix asm-avr32/dma-mapping.h breakage

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

On Wed, Oct 24 2007, Adrian Bunk wrote:
> On Wed, Oct 24, 2007 at 02:21:20PM +0200, Jens Axboe wrote:
> > On Wed, Oct 24 2007, Robert P. J. Day wrote:
> > > On Wed, 24 Oct 2007, Sam Ravnborg wrote:
> > > 
> > > > On Wed, Oct 24, 2007 at 01:24:53PM +0200, Jens Axboe wrote:
> > > > > On Wed, Oct 24 2007, Haavard Skinnemoen wrote:
> > > > > > Hi Linus,
> > > > > >
> > > > > > Sorry about sending you pull requests so rapidly, but Jens broke my
> > > > > > dma-mapping.h yesterday. Or you may say the bug was there to begin with
> > > > > > and Jens merely exposed it, but that makes it sound like my fault ;-)
> > > > > >
> > > > > > Anyway, please pull from
> > > > > >
> > > > > >   ssh://master.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6.git for-linus
> > > > > >
> > > > > > to receive the following update.
> > > > >
> > > > > You should not take the blame :-)
> > > > >
> > > > > I'm collecting these patches, so I'll pull your fix and make sure it
> > > > > gets to Linus today along with the other fixes.
> > > >
> > > > How about doing a "git grep asm/scatterlist"
> > > > and fix all victims to use linux/scatterlist?
> > > > Or you maybe did this already.
> > > 
> > > i was just about to ask -- is this one of those cases where the asm
> > > versions of scatterlist.h should have a warning/error that they should
> > > not be included directly, and to include linux/scatterlist.h instead?
> > 
> > No, using asm/scatterlist.h is perfectly fine. The problem is code using
> > the sg helpers should include linux/scatterlist.h since that is where
> > those are defined.
> > 
> > If you just need the scatterlist structure definition, then
> > asm/scatterlist.h is the correct include.
> 
> But there's also the general question whether it's good practice for 
> not architecture specific code to include asm/ headers.
> 
> For APIs available on all architectures linux/ header are the right 
> thing to use, and what is in the asm/ header and what in the linux/ 
> header becomes an implementation detail that can be changed.

I agree, for non-arch code you almost always want to use
linux/scatterlist.h since you should be using proper accessor methods
anyway.

-- 
Jens Axboe