On 05/25/2017 11:02 PM, Phil Edworthy wrote: > 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.
Well..i didn't agree yet... If mmc_set_clock(mmc, 400K) and mmc->cfg->f_min is 300K? Initial clock should be always 400K..but spec is mentioned "initial clock is maximum 400K.." It means the clock can be the value under 400K. > > Thanks > Phil > >>> >>> Signed-off-by: Phil Edworthy <phil.edwor...@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); >>> > > > > _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
