Re: [PATCH 1/3] at91_mci: Enable MMC_CAP_SDIO_IRQ only when itactually works

From: Pierre Ossman
Date: Fri Jul 18 2008 - 19:02:21 EST


On Fri, 18 Jul 2008 15:30:40 +0200
Nicolas Ferre <nicolas.ferre@xxxxxxxxx> wrote:

> Pierre Ossman :
> >
> > Not all SDIO cards use 4-bit mode, so it looks to me like you have to
> > disable it completely (unless there's a third revision where it works
> > without any fine print?).
>
> Well, I understand.
>
> In your opinion, a printed warning that says to be sure to use only
> 4-bit mode SDIO cards on slot B... is not acceptable ?
>

It's not really up to the user. The SDIO spec does not mandate 4-bit
support, so some cards will not have it.

> It kind of disappoints me to remove this feature as the
> at91sam9260ek/9xe/9g20 board uses only slot B, and I really like to
> connect SDIO with IRQ on it.
>

I haven't seen the erratum, but is there no way to poke the hardware
into getting the interrupt running even in 1-bit mode?

--
-- Pierre Ossman

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