On Sun, 3 Jan 2010 09:23:30 +1100
Ben Nizette <bn@xxxxxxxxxxxxxxx> wrote:
> >
> > Broken cards seem to be all over the spectrum, so I wouldn't be
> > suprised if you find ones that break if you go too low as well.
>
> Yea good point, though given there might not even be a One Freq to Rule Them All, how about:
>
> ---8<---
>
> From: Ben Nizette <bn@xxxxxxxxxxxxxxx>
> Subject: [PATCH v3] mmc: Make ID freq configurable
>
> While the SD spec specifies a range of frequencies for the ID phase from 100-400kHz, not all cards play by the rules. This patch adds a Kconfig option to allow the user to tweak this to their card/host config, though the default of 250kHz should be fine for all spec-abiding cards and most others besides.
>
> Signed-off-by: Ben Nizette <bn@xxxxxxxxxxxxxxx>
>
This is not a good solution. We all use the same pool of cards so we
should all be using the same init sequence. If there isn't a single
frequency where all cards will work, then we'll have to make something
more advanced where the kernel will try the init several times with
different clocking.
Rgds
--
-- Pierre Ossman
WARNING: This correspondence is being monitored by FRA, a
Swedish intelligence agency. Make sure your server uses
encryption for SMTP traffic and consider using PGP for
end-to-end encryption.
Attachment:
signature.asc
Description: PGP signature
