From mboxrd@z Thu Jan 1 00:00:00 1970 From: s.hauer@pengutronix.de (Sascha Hauer) Date: Mon, 21 Feb 2011 15:07:50 +0100 Subject: [PATCH v2] mxcmmc: use dmaengine API In-Reply-To: <201102181437.02943.arnd@arndb.de> References: <20110218092109.GG24426@pengutronix.de> <201102181437.02943.arnd@arndb.de> Message-ID: <20110221140750.GN24426@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 > > 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 -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |