Re: [PATCH 05/18] MMC: OMAP: Introduce new multislot structure andchange driver to use it

From: Pierre Ossman
Date: Thu Mar 06 2008 - 01:36:27 EST


On Wed, 5 Mar 2008 22:54:09 +0200
Felipe Balbi <me@xxxxxxxxxxxxxxx> wrote:

>
> Not nightmare. OMAP1/2 have mmc/sd/sdio controller supporting one or
> more mmc cards sharing the same bus.
>

Do you have some docs to that effect? All that's been presented to me so far is a standard, one port controller with a mux in front of it. Under that definition, all controllers support an infinite number of cards.

> > > +
> > > + mmc->caps = MMC_CAP_MULTIWRITE | MMC_CAP_MMC_HIGHSPEED |
> > > + MMC_CAP_SD_HIGHSPEED;
> >
> > This is also unrelated. From what I've seen, the OMAP is a SD controller and does not support high speed MMC. The fact that you also conditionally set the max frequency later also suggests that this code is entirely incorrect.
> >
>
> Not true. I can't show you not even parts of the technical documentation
> but OMAP has mmc/sd/sdio controller. On OMAP1/2 it handles several mmc
> cards sharing the same bus.
>

I'm afraid empirical data is insufficient. Show me a data sheet saying that OMAP controllers are designed in accordance with the newer MMC specs and I'll be happy.

And you'll have to do a lot better than that to convince me that older OMAP controllers are designed for standards that were written after the chips were released (i.e. high speed bus timings).

Rgds
--
-- Pierre Ossman

Linux kernel, MMC maintainer http://www.kernel.org
PulseAudio, core developer http://pulseaudio.org
rdesktop, core developer http://www.rdesktop.org
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