• Jan Kaisrlik's avatar
    Revert "mmc: core: do not retry CMD6 in __mmc_switch()" · 8ad8e02c
    Jan Kaisrlik authored
    Turns out the commit 3a0681c7 ("mmc: core: do not retry CMD6 in
    __mmc_switch()") breaks initialization of a Toshiba THGBMNG5 eMMC card,
    when using the meson-gx-mmc.c driver on a custom board based on Amlogic
    The CMD6 that switches the card into HS200 mode is then one that fails and
    according to the below printed messages from the log:
    [    1.648951] mmc0: mmc_select_hs200 failed, error -84
    [    1.648988] mmc0: error -84 whilst initialising MMC card
    After some analyze, it turns out that adding a delay of ~5ms inside
    mmc_select_bus_width() but after mmc_compare_ext_csds() has been executed,
    also fixes the problem. Adding yet some more debug code, trying to figure
    out if potentially the card could be in a busy state, both by using CMD13
    and ->card_busy() ops concluded that this was not the case.
    Therefore, let's simply revert the commit that dropped support for retrying
    of CMD6, as this also fixes the problem.
    Fixes: 3a0681c7 ("mmc: core: do not retry CMD6 in __mmc_switch()")
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarJan Kaisrlik <ja.kaisrlik@gmail.com>
    Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
mmc_ops.c 22.9 KB