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

Marek Vasut marex at denx.de
Wed Jan 23 12:26:58 CET 2013


Dear Otavio Salvador,

> On Wed, Jan 23, 2013 at 7:04 AM, Stefano Babic <sbabic at denx.de> wrote:
> > On 22/01/2013 02:56, Otavio Salvador wrote:
> >> On Mon, Jan 21, 2013 at 11:50 PM, Marek Vasut <marex at denx.de> wrote:
> >>> Dear Otavio Salvador,
> >>> 
> >>> NAK. DMA works on MX28 and works in Linux on MX23, therefore the DMA is
> >>> not broken on either. Thus there's no reason to introduce such
> >>> "force_pio" stuff.
> >> 
> >> Lack of time to work on it is one reason. I won't be able to work on
> >> it for some days and I prefer a working solution than skip it for
> >> another release.
> >> 
> >> --
> >> Otavio Salvador                             O.S. Systems
> >> E-mail: otavio at ossystems.com.br  http://www.ossystems.com.br
> >> Mobile: +55 53 9981-7854              http://projetos.ossystems.com.br
> > 
> > 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?

Best regards,
Marek Vasut


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