On Fri, 18 Jun 2010 13:05:44 +0900, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote:
> This patch is bug fixed..
> I think that host->ios.clock(initial clock) will be set lower than 400KHz.
> But in this code, if host->f_min is higher than 400KHz, print warning message and set higher than 400KHz.
> And We use SDHCI_QUIRK_NONSTANDARD_CLOCK..so using get_min_clock function.
> but didn't effect nothing through used get_min_clock function.
I'm a little confused. What problem are you fixing with this patch? What
issue are you seeing? SDHCI_QUIRK_NONSTANDARD_CLOCK is only for sdhci.
If this is the old "my card won't initialise at 400kHz" chestnut I don't
think a solution has ever been agreed upon. The problem was that while
some cards won't initialise at 400kHz, some controllers will try to
initialise at too low a frequency which causes other problems.
Sascha Hauer explains the reason for setting ios.clock to 400kHz here,
http://lkml.org/lkml/2010/1/5/120
So I think your patch will cause problems.
Which driver are you using? The driver should have set the f_min value
to be <= 400kHz. Maybe it is a good idea to set the value of ios.clock
to 400kHz if the driver has set a bogus f_min value, we will at least
have a fighting chance of initialising the card (though I would say that
the driver was broken, but at least core.c will print a warning).
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