[U-Boot] [v2] mmc: send CMD0 before CMD1 for some MMC cards

Jaehoon Chung jh80.chung at samsung.com
Tue Aug 9 01:06:14 CEST 2016


Hi Yangbo,

On 08/02/2016 04:33 PM, Yangbo Lu wrote:
> When the MMC framework was added in u-boot, the mmc_go_idle was
> added before mmc_send_op_cond_iter in function mmc_send_op_cond
> annotating that some cards seemed to need this. Actually, we still
> need to do this in function mmc_complete_op_cond for those cards.
> This has been verified on Micron MTFC4GACAECN eMMC chip.

This patch is not bad.. but i need to verify more about entire sequence.
Could you wait a bit?

Best Regards,
Jaehoon Chung

> 
> Signed-off-by: Yangbo Lu <yangbo.lu at nxp.com>
> ---
>  drivers/mmc/mmc.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
> index f8e5f7a..d4e96bc 100644
> --- a/drivers/mmc/mmc.c
> +++ b/drivers/mmc/mmc.c
> @@ -422,6 +422,9 @@ static int mmc_complete_op_cond(struct mmc *mmc)
>  
>  	mmc->op_cond_pending = 0;
>  	if (!(mmc->ocr & OCR_BUSY)) {
> +		/* Some cards seem to need this */
> +		mmc_go_idle(mmc);
> +
>  		start = get_timer(0);
>  		while (1) {
>  			err = mmc_send_op_cond_iter(mmc, 1);
> 



More information about the U-Boot mailing list