The SD spec version 6.0 section 6.4.1.5 requires that Vdd must be lowered to less than 0.5V for a minimum of 1 ms when powering off a card. Increase our wait to 10 ms so that voltage has time to drain down to 0.5V and cards can power off correctly.
Signed-off-by: Kyle Roeschley <[email protected]> --- drivers/mmc/core/core.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 66c9cf49ad2f..38630246de26 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1679,18 +1679,16 @@ void mmc_power_off(struct mmc_host *host) mmc_set_initial_state(host); /* - * Some configurations, such as the 802.11 SDIO card in the OLPC - * XO-1.5, require a short delay after poweroff before the card - * can be successfully turned on again. + * The SD spec requires at least 1 ms with Vdd at less than 0.5 V + * before a card can be re-powered, but we need to wait longer so that + * the voltage has time to drain. */ - mmc_delay(1); + mmc_delay(10); } void mmc_power_cycle(struct mmc_host *host, u32 ocr) { mmc_power_off(host); - /* Wait at least 1 ms according to SD spec */ - mmc_delay(1); mmc_power_up(host, ocr); } -- 2.14.1
