DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
  s=s1024; d=pacbell.net;
  h=Received:X-YMail-OSG:X-Yahoo-Newman-Property:From:Reply-To:To:Subject:Date:User-Agent:Cc:References:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-Disposition:Message-Id;
  b=Xg1n/9nxx9qdJA/3WurFIaUG13T1bTfoNCKuKR9kYPnrtAO7WAZhRc6sRVEm79Jk6dEYsJpyN2ZpPihxBiXBYCawDZFMLd2n8CfuOEL3z4TV+UvOB0kx2lL6S5Yqk4UbHRlEpFIVbQlqkXiq1WQu6XCFT+igSZ9NJHHjGxBJ9wY=  ;
From: David Brownell <david-b@pacbell.net>
Reply-To: dbrownell@users.sourceforge.net
To: Daniel Ribeiro <drwyrm@gmail.com>
Subject: Re: [spi-devel-general] [patch 05/14] mfd: PCAP2 driver
Date: Sun, 23 Nov 2008 00:26:10 -0800
User-Agent: KMail/1.9.10
Cc: Stefan Schmidt <stefan@datenfreihafen.org>,
       spi-devel-general@lists.sourceforge.net,
       Stefan Schmidt <stefan@openmoko.org>, eric.y.miao@gmail.com,
       linux-kernel@vger.kernel.org, sameo@openedhand.com,
       linux-arm-kernel@lists.arm.linux.org.uk
References: <20081121160403.073751031@dodger.lab.datenfreihafen.org> <200811222059.59806.david-b@pacbell.net> <1227423962.3148.74.camel@brutus>
In-Reply-To: <1227423962.3148.74.camel@brutus>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="us-ascii"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200811230026.11126.david-b@pacbell.net>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 672
Lines: 16

On Saturday 22 November 2008, Daniel Ribeiro wrote:
> Can you be more descriptive on "address the DMA"? Im not familiar on
> what is the issue here.

You may not pass stack based buffers -- as you're now doing -- for
the spi_transfer buffers.  Documentation/DMA-mapping.txt is very
clear that such buffers are not DMA-safe, and the SPI kerneldoc is
just as clear that spi_transfer.{tx,rx}_buf memory must be DMA-safe.

- Dave

--
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/