Date: Wed, 24 Oct 2007 14:41:23 +0200
From: Adrian Bunk <bunk@kernel.org>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: "Robert P. J. Day" <rpjday@crashcourse.ca>,
       Sam Ravnborg <sam@ravnborg.org>,
       Haavard Skinnemoen <hskinnemoen@atmel.no>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [GIT PATCH] Fix asm-avr32/dma-mapping.h breakage
Message-ID: <20071024124123.GD30533@stusta.de>
References: <20071024132220.14070582@dhcp-255-175.norway.atmel.com> <20071024112453.GP14671@kernel.dk> <20071024112938.GA1770@uranus.ravnborg.org> <Pine.LNX.4.64.0710240814570.31881@localhost.localdomain> <20071024122120.GV14671@kernel.dk>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <20071024122120.GV14671@kernel.dk>
User-Agent: Mutt/1.5.16 (2007-06-11)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 2439
Lines: 62

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.

> Jens Axboe

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/