On Sun, Jan 19, 2014 at 09:28:53PM +0100, Arnd Bergmann wrote:

On Sunday 19 January 2014, Olof Johansson wrote:

quoted

The "multi-slot" concept I was talking about was one host controller
for several physical slots. Seems like at91 implements and uses this
but nobody else. However, it seems that they allocate one mmc host per
slot, so the same model still works.

IIRC dw-mci also has multiple slots, and it's a common host controller
in a number of SoCs. I don't know how many of them actually support
multiple slots rather than a simplified single-slot version of
that controller.

Right, that's the main one i had in mind -- the binding, and the driver, allow
for multiple slots but we've been searching high and low for an actual SoC that
implements that, and none seem to do it. So the additional overhead is just
wasted, and there's been talk of bringing the binding more in line with
a single-slot driver instead. It makes a lot of sense to do.


-Olof