mmc: debugfs: Add a restriction to mmc debugfs clock setting

commit e5905ff1281f0a0f5c9863c430ac1ed5faaf5707 upstream.

Clock frequency values written to an mmc host should not be less than
the minimum clock frequency which the mmc host supports.

Signed-off-by: Yuan Juntao <juntaox.yuan@intel.com>
Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
index 154aced0b91b63e33cb95a9ba1a82e386395392d..705586dcd9fa22fa380cf1572b56907ae615b702 100644 (file)
--- a/drivers/mmc/core/debugfs.c
+++ b/drivers/mmc/core/debugfs.c
@@ -220,7 +220,7 @@ static int mmc_clock_opt_set(void *data, u64 val)
        struct mmc_host *host = data;
 
        /* We need this check due to input value is u64 */
-       if (val > host->f_max)
+       if (val != 0 && (val > host->f_max || val < host->f_min))
                return -EINVAL;
 
        mmc_claim_host(host);