[U-Boot] [PATCH 9/9] mx23: Use PIO mode support for MMC

Marek Vasut
2013-01-23T11:48:26Z

Dear Stefano Babic,

> On 23/01/2013 12:26, Marek Vasut wrote:
> >>> Hi Otavio, hi Marek,
> >>>
> >>> let me say some words about this discussion. I agree that if there is
> >>> no support for DMA for MX23, we could add support with PIO mode.
> >>> However, there should be a very good reason, because as far as I
> >>> understand, added support for DMA is valid for mxs platform. The
> >>> solution introduced with this patchset lets also the door open for
> >>> people that can use MX28 in PIO mode. I think (I have already seen in
> >>> ML Marek's patchset for it) the way to fix DMA for mx23 and then add
> >>> support for MMC is the rught way to do.
> >>
> >> So you'd like to have this patch ported to Marek's patchset so the
> >> support for PIO mode is kept available? Instead of enabling it for
> >> MX23 we can have a config option which allows force PIO mode and
> >> disable DMA. This is what you want?
> >
> > Forcing PIO is nonsense, why would it be of any use?
>
> No, I agree with Marek - if DMA is then working also for MX23, we do not
> need PIO at all.

Stefano, it's now using mixed mode -- PIO for small transfers, DMA for large
transfers. That is the best pick of both worlds ;-)

Best regards,
Marek Vasut