Re: [patch 2.6.28] mmc: warn about voltage mismatches

From: Pierre Ossman
Date: Wed Dec 31 2008 - 13:27:38 EST


On Wed, 31 Dec 2008 09:50:30 -0800
David Brownell <david-b@xxxxxxxxxxx> wrote:

> From: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
>
> Get rid of a silent failure mode when the MMC/SD host doesn't
> support the voltages needed to operate a given card, by
> adding a warning. A 3.3V host and a 3.0V card, for example,
> no longer need to mysteriously just not work at all.
>

Hmm... I have sort of always assumed that 3.3V was always required by
the host and card, but re-reading the specs that clearly isn't the case.

> This isn't the best diagnostic; ideally it would also tell
> what voltage the card and host support (and not just by
> dumping the bitmasks).
>

Still, it's better than nothing.

> Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
> ---

Queued.

--
-- Pierre Ossman

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

WARNING: This correspondence is being monitored by the
Swedish government. Make sure your server uses encryption
for SMTP traffic and consider using PGP for end-to-end
encryption.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/