Hi Sascha, Sascha Hauer wrote: > No need to limit the clock to the cards capabilities since the values > passed to mci_set_clock are based on the cards capabilities. This > enables MMC high speed cards to operate at higher speeds since on > this cards the csd field only holds the non highspeed maximum clock. > > Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> > --- > drivers/mci/mci-core.c | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c > index 283df2f..895108f 100644 > --- a/drivers/mci/mci-core.c > +++ b/drivers/mci/mci-core.c > @@ -664,10 +664,6 @@ static void mci_set_clock(struct mci *mci, unsigned clock) > if (clock < host->f_min) > clock = host->f_min; > > - /* check against the limit at the card's side */ > - if (mci->tran_speed != 0 && clock > mci->tran_speed) > - clock = mci->tran_speed; > - > host->clock = clock; /* the new target frequency */ > mci_set_ios(mci); > } I'm not sure. In mci_startup_sd() there is a very primitive decision for the clock frequency. /* if possible, speed up the transfer */ if (mci->card_caps & MMC_MODE_HS) mci_set_clock(mci, 50000000); else mci_set_clock(mci, 25000000); And yes, the spec tells us, there are two cards at 3.3 V available: 25 MHz and 50 MHz. But theoretically a vendor can limit the max transfer speed to a different value. I'm confused about the spec here, as the card reports a max transfer speed *and* a standard/high speed bit. Which one is reliable? jbe -- Pengutronix e.K. | Juergen Beisert | Linux Solutions for Science and Industry | http://www.pengutronix.de/ | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
