Subject: [RFC PATCH v3 11/16] mmc: omap_hsmmc: limit max_segs with the EDMA DMAC

From: [email-masked] (Matt Porter)
Date: Thu, 10 Jan 2013 14:30:28 -0500

On Mon, Oct 29, 2012 at 01:48:46PM +0530, Sekhar Nori wrote:
> On 10/18/2012 6:56 PM, Matt Porter wrote:
> > The EDMA DMAC has a hardware limitation that prevents supporting
> > scatter gather lists with any number of segments. Since the EDMA
> > DMA Engine driver sets the maximum segments to 16, we do the
> > same.
> > 
> > TODO: this will be replaced once the DMA Engine API supports an
> > API to query the DMAC's segment size limit.
> > 
> > Signed-off-by: Matt Porter <[email-masked]>
> > ---
> >  drivers/mmc/host/omap_hsmmc.c |   10 ++++++++++
> >  1 file changed, 10 insertions(+)
> > 
> > diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
> > index b327cd0..52bab01 100644
> > --- a/drivers/mmc/host/omap_hsmmc.c
> > +++ b/drivers/mmc/host/omap_hsmmc.c
> > @@ -1828,6 +1828,16 @@ static int __devinit omap_hsmmc_probe(struct platform_device *pdev)
> >  	 * as we want. */
> >  	mmc->max_segs = 1024;
> >  
> > +	/* Eventually we should get our max_segs limitation for EDMA by
> > +	 * querying the dmaengine API */
> 
> Nit picking: This is not as per multi-line comment style in
> Documentation/CodingStyle.

Thanks :). This is dropped from v4 anyway, as I now use a call to
dma_get_channel_caps() to determine the SG limits.

-Matt