[PATCH v2] mxcmmc: use dmaengine API

Sascha Hauer s.hauer at pengutronix.de
Mon Feb 21 09:07:50 EST 2011


On Fri, Feb 18, 2011 at 02:37:02PM +0100, Arnd Bergmann wrote:
> On Friday 18 February 2011, Sascha Hauer wrote:
> > This switches the mxcmmc driver to use the dmaengine API. Unlike
> > the old one this one is always present in the tree, even if no DMA
> > is implemented, hence we can remove all the #ifdefs in from the driver.
> > The driver automatically switches to PIO mode if no DMA support or no
> > suitable channel is available.
> > 
> > Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> 
> The patch looks good to me, but shouldn't you also add a Kconfig
> dependency or select on CONFIG_DMA_ENGINE? I don't see where that
> gets set.

I was about to answer with a patch adding a select on CONFIG_DMA_ENGINE
but just realized this isn't necessary. Without dmaengine support
dma_request_channel becomes a static inline returning NULL. The mxcmmc
driver falls back to PIO then and still works.

Sascha


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