[PATCH 1/2] sdhci: add quirk for lack of 1.8v support

[Chris Ball]

Hi,

On Sun, Nov 25 2012, Daniel Drake wrote:
> The OLPC XO-1.75 laptop includes a SDHCI controller which is 1.8v
> capable, and it truthfully reports so in its capabilities. This
> alternate voltage is used for driving new "UHS-I" SD cards at their
> full speed.
>
> However, what the controller doesn't know is that the motherboard
> physically doesn't have a 1.8v supply available.
>
> Add a quirk so that systems such as this one can override disable
> 1.8v support, adding support for UHS-I cards (by running them at
> 3.3v).
>
> This avoids a problem where the system would first try to run the
> card at 1.8v, fail, and then not be able to fully reset the card
> to retry at the normal 3.3v voltage.
>
> This is more appropriate than using the MISSING_CAPS quirk, which
> is intended for cases where the SDHCI controller is actually lying
> about its capabilities, and would force us to somehow override both
> caps words from another source.
>
> Signed-off-by: Daniel Drake <dsd at laptop.org>

Thanks, pushed to mmc-next for 3.8.

- Chris.
-- 
Chris Ball   <cjb at laptop.org>   <http://printf.net/>
One Laptop Per Child