Messages in this thread | | | Date | Fri, 21 Sep 2012 20:18:41 +0300 | From | Felipe Balbi <> | Subject | Re: [RFC PATCH 08/13] mmc: omap_hsmmc: limit max_segs with the EDMA DMAC |
| |
On Fri, Sep 21, 2012 at 10:47:30PM +0530, S, Venkatraman wrote: > On Fri, Sep 21, 2012 at 10:45 PM, S, Venkatraman <svenkatr@ti.com> wrote: > > On Thu, Sep 20, 2012 at 8:13 PM, Matt Porter <mporter@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 ? > > If you are adventurous, this can be a generic mmc DT binding instead > of restricting it to OMAP.
I say if it's a limitation in the DMAC, then DMAC's driver should handle it, no ? Meaning that in this case you would copy from one multi-segment sg into a one-segment sg and when transfer is complete, before calling user's callback, copy data the other way around (?)
-- balbi [unhandled content-type:application/pgp-signature] | |