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

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>

diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
index 65cc0ac9b82d2b9e1eb928131c7a1dea074f2d02..9382a57a5aa496f19c22353521fe475e1d253c91 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);