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    SubjectRe: [PATCH 5/7] mmc_spi: allow higher timeouts for SPI mode
    On Wed, 11 Mar 2009 14:28:39 +0100
    Wolfgang Mües <wolfgang.mues@auerswald.de> wrote:

    > From: Wolfgang Muees <wolfgang.mues@auerswald.de>
    >
    > o Some SD cards have very high timeouts in SPI mode.
    > So adjust the timeouts from theory to practice.
    >
    > Signed-off-by: Wolfgang Muees <wolfgang.mues@auerswald.de>
    >
    > ---
    > This is one of a line of patches to enhance the usability of
    > the mmc spi host port driver from "don't work with most SD cards"
    > to "work with nearly all SD cards" (including those ugly cards
    > with non-byte-aligned responses).
    >
    > diff -uprN 2_6_29_rc7_patch4_no_crc_on_CID_CSD/drivers/mmc/core/core.c 2_6_29_rc7_patch5_extra_spi_timeouts/drivers/mmc/core/core.c
    > --- 2_6_29_rc7_patch4_no_crc_on_CID_CSD/drivers/mmc/core/core.c 2009-03-04 02:05:22.000000000 +0100
    > +++ 2_6_29_rc7_patch5_extra_spi_timeouts/drivers/mmc/core/core.c 2009-03-10 12:06:16.000000000 +0100
    > @@ -297,6 +297,21 @@ void mmc_set_data_timeout(struct mmc_dat
    > data->timeout_clks = 0;
    > }
    > }
    > + /*
    > + * Some cards need very high timeouts if driven in SPI mode.
    > + * The worst observed timeout was 900ms after writing a
    > + * continuous stream of data until the internal logic
    > + * overflowed.
    > + */
    > + if (mmc_host_is_spi(card->host)) {
    > + if (data->flags & MMC_DATA_WRITE) {
    > + if (data->timeout_ns < 1000000000)
    > + data->timeout_ns = 1000000000; /* 1s */
    > + } else {
    > + if (data->timeout_ns < 100000000)
    > + data->timeout_ns = 100000000; /* 100ms */
    > + }
    > + }
    > }
    > EXPORT_SYMBOL(mmc_set_data_timeout);
    >

    In the future, there are macros called NSEC_PER_SEC and similar that
    can be used to increase readability instead of the comments.

    Rgds
    --
    -- Pierre Ossman

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