[U-Boot] [PATCH] mmc: Set the initial clock speed to 400KHz

[Phil Edworthy]

Hi Jaehoon Chung,

On 25 May 2017 14:50 Jaehoon Chung wrote:
> Hi,
> 
> On 05/24/2017 10:54 PM, Phil Edworthy wrote:
> > The code currently defaults to the slowest clock speed that can be
> > achieved, which can be significantly lower than the SD spec.
> 
> Is there any problem..As i know, it should be changed from 1 to min_clk.
The only problem is that the initial SD clock can be very slow so it increases
the time to start SD. Admittedly, it's a very small increase in time, but we
should use the correct initial clock speed.

Thanks
Phil

> >
> > Signed-off-by: Phil Edworthy <phil.edworthy at renesas.com>
> > ---
> >  drivers/mmc/mmc.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index
> > 72fc177..dff1be3 100644
> > --- a/drivers/mmc/mmc.c
> > +++ b/drivers/mmc/mmc.c
> > @@ -1676,7 +1676,7 @@ int mmc_start_init(struct mmc *mmc)  #endif
> >  	mmc->ddr_mode = 0;
> >  	mmc_set_bus_width(mmc, 1);
> > -	mmc_set_clock(mmc, 1);
> > +	mmc_set_clock(mmc, 400000);
> >
> >  	/* Reset the Card */
> >  	err = mmc_go_idle(mmc);
> >