diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 3bebd3b55dc5..bffcaf8df352 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -460,12 +460,20 @@ static void mmc_power_up(struct mmc_host *host) host->ios.timing = MMC_TIMING_LEGACY; mmc_set_ios(host); - mmc_delay(1); + /* + * This delay should be sufficient to allow the power supply + * to reach the minimum voltage. + */ + mmc_delay(2); host->ios.clock = host->f_min; host->ios.power_mode = MMC_POWER_ON; mmc_set_ios(host); + /* + * This delay must be at least 74 clock sizes, or 1 ms, or the + * time required to reach a stable voltage. + */ mmc_delay(2); }