From: Sascha Hauer <s.hauer@pengutronix.de>
To: Anatolij Gustschin <agust@denx.de>
Cc: linux-mmc@vger.kernel.org, Chris Ball <cjb@laptop.org>,
Markus Pargmann <mpa@pengutronix.de>,
devicetree-discuss@lists.ozlabs.org
Subject: Re: [PATCH 4/5] mmc: mxcmmc: enable DMA support on mpc512x
Date: Thu, 14 Mar 2013 21:11:39 +0100 [thread overview]
Message-ID: <20130314201139.GS1906@pengutronix.de> (raw)
In-Reply-To: <1363279254-22351-6-git-send-email-agust@denx.de>
On Thu, Mar 14, 2013 at 05:40:53PM +0100, Anatolij Gustschin wrote:
> Add SDHC DMA channel description to the mpc512x device
> tree to enable slave channel requesting in the mxcmmc
> driver.
>
> mpc512x DMA engine doesn't support endianness conversion
> when reading/writing data from peripheral's FIFO, so we
> have to swap data buffers before each DMA write and after
> each DMA read transfer manually.
>
> Since chained SDHC DMA transfers are not supported on
> mpc512x, limit 'max_segs' tunable parameter to one and
> initialise it to 64 only when running on i.MX platforms.
They are also not supported on the older i.MX platforms. Shouldn't this
be handled in the DMA driver?
Sascha
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next prev parent reply other threads:[~2013-03-14 20:11 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-14 16:40 [PATCH 0/5] mmc: mxcmmc: add mpc512x support Anatolij Gustschin
2013-03-14 16:40 ` [PATCH 1/5] mmc: mxcmmc: add mpc512x SDHC support Anatolij Gustschin
2013-03-14 16:50 ` Arnd Bergmann
2013-03-14 18:13 ` Anatolij Gustschin
2013-03-14 20:05 ` Sascha Hauer
2013-03-14 22:52 ` Arnd Bergmann
2013-03-14 16:40 ` [PATCH 2/5] mmc: mxcmmc: use slot-gpio API for write-protect detection Anatolij Gustschin
2013-03-14 16:40 ` [PATCH 3/5] mmc: mxcmmc: constify mxcmci_devtype and fix build warning Anatolij Gustschin
2013-03-14 16:40 ` Anatolij Gustschin
2013-03-14 18:15 ` Anatolij Gustschin
2013-03-14 16:40 ` [PATCH 4/5] mmc: mxcmmc: enable DMA support on mpc512x Anatolij Gustschin
2013-03-14 20:11 ` Sascha Hauer [this message]
2013-03-14 21:18 ` Anatolij Gustschin
2013-03-14 16:40 ` [PATCH 5/5] mmc: mxcmmc: fix race conditions for host->req and host->data access Anatolij Gustschin
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