From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Weiner <jw@emlix.com>
Subject: Re: [LKML] Re: [PATCH v3] ad7877: keep dma rx buffers in seperate
 cache lines
Date: Wed, 19 May 2010 15:44:30 +0200
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To: Nick Piggin <npiggin@suse.de>
Cc: David Woodhouse <dwmw2@infradead.org>, Marc Gauthier <marc@tensilica.com>, Mike Frysinger <vapier.adi@gmail.com>, Dmitry Torokhov <dmitry.torokhov@gmail.com>, Christoph Lameter <cl@linux.com>, Pekka Enberg <penberg@cs.helsinki.fi>, Matt Mackall <mpm@selenic.com>, Andrew Morton <akpm@linux-foundation.org>, Oskar Schirmer <os@emlix.com>, Michael Hennerich <Michael.Hennerich@analog.com>, "linux-input@vger.kernel.org" <linux-input@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Daniel =?iso-8859-1?Q?Gl=F6ckner?= <dg@emlix.com>, Oliver Schneidewind <osw@emlix.com>, David Rientjes <rientjes@google.com>, David Brownell <dbrownell@users.sourceforge.net>, Grant Likely <grant.likely@secretlab.ca>, Chris Zankel <chris@zankel.net>, Piet Delaney <Piet.Delaney@tensilica.com>

On Wed, May 19, 2010 at 11:36:56PM +1000, Nick Piggin wrote:
> On Wed, May 19, 2010 at 02:17:47PM +0100, David Woodhouse wrote:
> >
> > The 'cacheline aligned' misconception did manage to get into the ad7877
> > driver in commit 3843384a though -- it now uses ____cacheline_aligned
> > instead of __attribute__((__aligned__(ARCH_KMALLOC_MINALIGN))) as it
> > should.
> 
> OK so long as there is not a "must be cacheline aligned" requirement.
> Your proposal for a __dma_aligned attribute in an arch header looks
> like a good idea there.

Would you happen to know of other potential users?  At this point I'd
much rather just allocate the buffers dynamically and hide the issue
nicely behind kmalloc().