Re: [PATCH] mmc_spi: fail gracefully if host or card do not supportthe switch command

[Pierre Ossman]

On Mon, 15 Jun 2009 10:36:05 +0200
Wolfgang MÃes <wolfgang.mues@xxxxxxxxxxxx> wrote:

> Am Samstag, 13. Juni 2009 schrieb Pierre Ossman:
> > For SD there are several checks 
> > before the switch command is actually issued.
> 
> But there are two cases not covered by these checks:
> 
> a) the switch command is supported, but the card is not capable of switching 
> to 50 MHz.
> 

But a successful switch command (even if the response is that the card
cannot do it) should not need the checks you added. The switch data
structure is checked further down.

> b) the card rejects the switch command in SPI mode, because it is not 
> mandatory here.

I cannot see anything in the spec backing up this claim.

Rgds
-- 
     -- Pierre Ossman

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