On 03/28/2012 12:28 PM, [email protected] : > From: Ludovic Desroches <[email protected]> > > The HSMCI operates at a rate of up to Master Clock divided by two. > Moreover previous calculation can cause overflows and so wrong > timeouts. > > Signed-off-by: Ludovic Desroches <[email protected]>
Acked-by: Nicolas Ferre <[email protected]> > Cc: stable <[email protected]> > --- > drivers/mmc/host/atmel-mci.c | 9 ++++++++- > 1 files changed, 8 insertions(+), 1 deletions(-) > > diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c > index e4449a5..3a57964 100644 > --- a/drivers/mmc/host/atmel-mci.c > +++ b/drivers/mmc/host/atmel-mci.c > @@ -480,7 +480,14 @@ err: > static inline unsigned int atmci_ns_to_clocks(struct atmel_mci *host, > unsigned int ns) > { > - return (ns * (host->bus_hz / 1000000) + 999) / 1000; > + /* > + * It is easier here to use us instead of ns for the timeout, > + * it prevents from overflows during calculation. > + */ > + unsigned int us = DIV_ROUND_UP(ns, 1000); > + > + /* Maximum clock frequency is host->bus_hz/2 */ > + return us * (DIV_ROUND_UP(host->bus_hz, 2000000)); > } > > static void atmci_set_timeout(struct atmel_mci *host, -- Nicolas Ferre -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
