[PATCH 05/12] mmc: omap_hsmmc: add DMA engine support

[Russell King - ARM Linux]

On Fri, Apr 27, 2012 at 09:00:22PM +0200, Linus Walleij wrote:
> On Mon, Apr 23, 2012 at 6:05 PM, Russell King
> <rmk+kernel at arm.linux.org.uk> wrote:
> 
> > Add DMA engine support to the OMAP HSMMC driver.  This supplements the
> > private DMA API implementation contained within this driver, and the
> > driver can be switched at build time between using DMA engine and the
> > private DMA API.
> >
> > Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
> 
> Great,
> 
> > +#if 1
> > +               sig = host->dma_line_rx;
> > +               host->rx_chan = dma_request_channel(mask, omap_dma_filter_fn, &sig);
> > +               if (!host->rx_chan) {
> > +                       dev_warn(mmc_dev(host->mmc), "unable to obtain RX DMA engine channel %u\n", sig);
> > +               }
> > +#endif
> > +#if 1
> > +               sig = host->dma_line_tx;
> > +               host->tx_chan = dma_request_channel(mask, omap_dma_filter_fn, &sig);
> > +               if (!host->tx_chan) {
> > +                       dev_warn(mmc_dev(host->mmc), "unable to obtain TX DMA engine channel %u\n", sig);
> > +               }
> > +#endif
> 
> Are these development artifacts?

Read the commit message. ;)

They're there (and removed by the next patch) so that the driver can
be easily switched between DMA engine and the private DMA API.  Simply
change the relevant #if to zero at build time.

I don't think it warrants config symbols or trying to do it via module
params as its just a stepping stone through the process.