• Adrian Hunter's avatar
    mmc: sdhci: Fix recovery from tuning timeout · 6fe58456
    Adrian Hunter authored
    [ Upstream commit 61e53bd0 ]
    
    Clearing the tuning bits should reset the tuning circuit. However there is
    more to do. Reset the command and data lines for good measure, and then
    for eMMC ensure the card is not still trying to process a tuning command by
    sending a stop command.
    
    Note the JEDEC eMMC specification says the stop command (CMD12) can be used
    to stop a tuning command (CMD21) whereas the SD specification is silent on
    the subject with respect to the SD tuning command (CMD19). Considering that
    CMD12 is not a valid SDIO command, the stop command is sent only when the
    tuning command is CMD21 i.e. for eMMC. That addresses cases seen so far
    which have been on eMMC.
    
    Note that this replaces the commit fe5fb2e3 ("mmc: sdhci: Reset cmd and
    data circuits after tuning failure") which is being reverted for v4.9+.
    Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
    Tested-by: default avatarDan O'Donovan <dan@emutex.com>
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
    Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
    6fe58456
sdhci.c 88.6 KB