development kernel tree: Changes to 'andy'

git at git at
Wed Jul 16 09:26:58 CEST 2008

Rebased ref, commits from common ancestor:
commit 48726b4cb4c2cd264ecc87beed5ee5600b5f012f
Author: Andy Green <andy at>
Date:   Tue Jul 15 17:21:45 2008 +0100

    This patch allows you to control the maximum clock rate that will
    be selected for SD Card access, from the kernel commandline using
    and also from
     echo 10000000 > /sys/module/glamo_mci/parameters/sd_max_clk
    although you have to suspend and resume to make the limit operational
    on the actual SD_CLK line.
    Clocks that are possible are divided down from ~50MHz, so 25000000,
    16666666, 12500000, 10000000, etc.  With Freerunner A5 revision that
    has 100R series resistors in SD Card signals, I didn't get reliable
    operation above 16MHz.  With A6 revision the series resistors went
    down to 75R, maybe it can work at 25MHz.
    Reducing the clock rate is something to try if you find that your
    SD Card is not communicating properly with the default speed.
    Signed-off-by: Andy Green <andy at>

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