[RFC PATCH 08/13] mmc: omap_hsmmc: limit max_segs with the EDMA DMAC

Russell King - ARM Linux linux at arm.linux.org.uk
Fri Sep 21 14:47:21 EDT 2012

On Fri, Sep 21, 2012 at 10:45:29PM +0530, S, Venkatraman wrote:
> On Thu, Sep 20, 2012 at 8:13 PM, Matt Porter <mporter at ti.com> 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.
> >
> > Note: this can be removed once the DMA Engine API supports an
> > API to query the DMAC's segment limitations.
> >
> I wouldn't want to bind the properties of EDMA to omap_hsmmc as this patch
> suggests. Why don't we have a max_segs property, which when explicitly specified
> in DT, will override the default ?

Why not have a generic way that DMA engine can export these kinds of

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