> Subject: [PATCH v2] mmc: retry CMD1 in mmc_send_op_cond() until the
> eMMC is ready
>
> From: Haibo Chen
>
> According to eMMC specification v5.1 section 6.4.3, we should issue
> CMD1 repeatedly in the idle state until the eMMC is ready even if
> mmc_send_op_cond() send CMD1 with argument = 0. Otherwise some
> eMMC devices seems to enter the inactive mode after
> mmc_complete_op_cond() issued CMD0 when the eMMC device is busy.
>
> Signed-off-by: Haibo Chen
> ---
> drivers/mmc/mmc.c | 9 -
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index
> 85762b82e0..475f75fc64 100644
> --- a/drivers/mmc/mmc.c
> +++ b/drivers/mmc/mmc.c
> @@ -662,12 +662,15 @@ static int mmc_send_op_cond_iter(struct mmc
> *mmc, int use_arg) static int mmc_send_op_cond(struct mmc *mmc) {
> int err, i;
> + int timeout = 1000;
> + uint start;
>
> /* Some cards seem to need this */
> mmc_go_idle(mmc);
>
> + start = get_timer(0);
> /* Asking to the card its capabilities */
> - for (i = 0; i < 2; i++) {
> + for (i = 0; ; i++) {
> err = mmc_send_op_cond_iter(mmc, i != 0);
> if (err)
> return err;
> @@ -675,6 +678,10 @@ static int mmc_send_op_cond(struct mmc *mmc)
> /* exit if not busy (flag seems to be inverted) */
> if (mmc->ocr & OCR_BUSY)
> break;
> +
> + if (get_timer(start) > timeout)
> + return -ETIMEDOUT;
> + udelay(100);
The Linux code use 10ms delay, but it should be fine here.
Reviewed-by: Peng Fan
> }
> mmc->op_cond_pending = 1;
> return 0;
> --
> 2.17.1
