[U-Boot] [PATCH 4/6] mmc: Continue polling MMC card for OCR only if it is still not ready

[Pantelis Antoniou]

Hi Andrew,

> On Mar 19, 2015, at 14:44 , Andrew Gabbasov <andrew_gabbasov at mentor.com> wrote:
> 
> Some MMC cards come to ready state quite quickly, so that the respective
> flag appears to be set in mmc_send_op_cond already. In this case trying
> to continue polling the card with CMD1 in mmc_complete_op_cond is incorrect
> and may lead to unpredictable results. So check the flag before polling
> and skip it appropriately.
> 
> Signed-off-by: Andrew Gabbasov <andrew_gabbasov at mentor.com>
> ---
> drivers/mmc/mmc.c | 20 +++++++++++---------
> 1 file changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
> index d073d79..42af47c 100644
> --- a/drivers/mmc/mmc.c
> +++ b/drivers/mmc/mmc.c
> @@ -403,15 +403,17 @@ static int mmc_complete_op_cond(struct mmc *mmc)
> 	int err;
> 
> 	mmc->op_cond_pending = 0;
> -	start = get_timer(0);
> -	do {
> -		err = mmc_send_op_cond_iter(mmc, 1);
> -		if (err)
> -			return err;
> -		if (get_timer(start) > timeout)
> -			return UNUSABLE_ERR;
> -		udelay(100);
> -	} while (!(mmc->ocr & OCR_BUSY));
> +	if (!(mmc->ocr & OCR_BUSY)) {
> +		start = get_timer(0);
> +		do {
> +			err = mmc_send_op_cond_iter(mmc, 1);
> +			if (err)
> +				return err;
> +			if (get_timer(start) > timeout)
> +				return UNUSABLE_ERR;
> +			udelay(100);
> +		} while (!(mmc->ocr & OCR_BUSY));
> +	}
> 
> 	if (mmc_host_is_spi(mmc)) { /* read OCR for spi */
> 		cmd.cmdidx = MMC_CMD_SPI_READ_OCR;
> -- 
> 2.1.0
> 


Thanks, Applied.

— Pantelis

PS. Peng, I’m picking up this instead of your patch.