According to spec, the maximum power up time is 35ms. Please refer to below spec for sd and emmc: "SD Physical Layer Specification 4.10, chapter 6.4.1.2 Power Up Time of Host." "JEDEC 4.5.1, chapter 10.3.3 Power supply voltages." Signed-off-by: Kevin Liu <kliu5@xxxxxxxxxxx> --- drivers/mmc/core/core.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 538c8d9..e8e7a85 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1490,10 +1490,9 @@ static void mmc_power_up(struct mmc_host *host) __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330); /* - * This delay should be sufficient to allow the power supply - * to reach the minimum voltage. + * The maximum power ramp up time is 35ms according to spec. */ - mmc_delay(10); + mmc_delay(35); host->ios.clock = host->f_init; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
