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From: Mike Frysinger <vapier.adi@gmail.com>
Date: Mon, 10 May 2010 12:39:49 -0400
Message-ID: <AANLkTiniq9gT5-x8tP3SRXvMvTAZ3VJF7pe21OLl1qDH@mail.gmail.com>
Subject: Re: [PATCH v3] ad7877: keep dma rx buffers in seperate cache lines
To: Oskar Schirmer <os@emlix.com>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>,
       Dmitry Torokhov <dmitry.torokhov@gmail.com>,
       Andrew Morton <akpm@linux-foundation.org>, linux-input@vger.kernel.org,
       linux-kernel@vger.kernel.org,
       =?UTF-8?Q?Daniel_Gl=C3=B6ckner?= <dg@emlix.com>,
       Oliver Schneidewind <osw@emlix.com>, Johannes Weiner <jw@emlix.com>
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On Mon, May 10, 2010 at 06:42, Oskar Schirmer wrote:
> With dma based spi transmission, data corruption
> is observed occasionally. With dma buffers located
> right next to msg and xfer fields, cache lines
> correctly flushed in preparation for dma usage
> may be polluted again when writing to fields
> in the same cache line.
>
> Make sure cache fields used with dma do not
> share cache lines with fields changed during
> dma handling. As both fields are part of a
> struct that is allocated via kzalloc, thus
> cache aligned, moving the fields to the 1st
> position and insert padding for alignment
> does the job.

Acked-by: Mike Frysinger <vapier@gentoo.org>

i'm guessing Dmitry will pick it up now
-mike