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From: David Brownell <david-b@pacbell.net>
To: Daniel Ribeiro <drwyrm@gmail.com>
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
Subject: Re: [spi-devel-general] [patch 05/14] mfd: PCAP2 driver
Date: Sun, 23 Nov 2008 00:26:10 -0800	[thread overview]
Message-ID: <200811230026.11126.david-b@pacbell.net> (raw)
In-Reply-To: <1227423962.3148.74.camel@brutus>

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


  reply	other threads:[~2008-11-23  8:26 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20081121160403.073751031@dodger.lab.datenfreihafen.org>
2008-11-21 16:04 ` stefan
2008-11-22  5:25   ` [spi-devel-general] " David Brownell
2008-11-22 14:01     ` Eric Miao
2008-11-22 15:54       ` Daniel Ribeiro
2008-11-22 19:08         ` David Brownell
2008-11-22 23:29           ` Stefan Schmidt
2008-11-22 17:12     ` Daniel Ribeiro
2008-11-22 19:19       ` David Brownell
2008-11-22 23:33         ` Stefan Schmidt
2008-11-22 23:58           ` David Brownell
2008-11-23  0:33             ` Stefan Schmidt
2008-11-23  2:19               ` David Brownell
2008-11-23  3:38                 ` Daniel Ribeiro
2008-11-23  4:59                   ` David Brownell
2008-11-23  7:06                     ` Daniel Ribeiro
2008-11-23  8:26                       ` David Brownell [this message]
2008-11-21 16:04 ` [patch 08/14] input: PCAP2 based touchscreen driver stefan
2008-11-21 17:05   ` Dmitry Torokhov
2008-11-22  0:00     ` Stefan Schmidt
2009-04-21  2:18       ` Dmitry Torokhov
2009-04-21  2:38         ` Daniel Ribeiro
2008-11-21 16:04 ` [patch 10/14] LED: PCAP2 based LED driver stefan
2008-11-22 14:08   ` Eric Miao
2008-11-22 15:46     ` Daniel Ribeiro

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