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    SubjectRe: [RFC] mmc: add OMAP driver
    One additional comment on the patch which I missed, and has shown to
    be a related cause of problems on a different host controller...

    On Thu, Feb 16, 2006 at 10:27:22AM -0400, Carlos Aguiar wrote:
    > +static inline void set_data_timeout(struct mmc_omap_host *host, struct mmc_request *req)
    > +{
    > + int timeout;
    > + u16 reg;
    > +
    > + /* Convert ns to clock cycles by assuming 20MHz frequency
    > + * 1 cycle at 20MHz = 500 ns
    > + */
    > + timeout = req->data->timeout_clks + req->data->timeout_ns / 500;
    > +
    > + /* Some cards require more time to do at least the first read operation */
    > + timeout = timeout << 4;

    This is a hack because you got your calculation above wrong. If you
    assume a fast clock, the timeout will be too slow for a slower clock.
    If you do the calculation correctly and you won't need such hacks.

    --
    Russell King
    Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
    maintainer of: 2.6 Serial core
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