Re: [PATCH] mmc: Add delay between CMD6 and CMD13 for Sandisk eMMC cards

[Jaehoon Chung]

Hi,

On 09/09/2014 09:26 PM, Jean-Michel Hautbois wrote:
> Tested on a i.MX6 board, with Sandisk SDIN5D1-2G.
> Without this patch, I/O errors occur.
> This eMMC seems to have a different Manufacturer ID as it reads 0x45
> and not 0x2 as specified in datasheet.

I think this patch don't merge into mainline.
This is not solution for problem.
you mentioned the below comment, this is workaround.

> 
> Signed-off-by: Jean-Michel Hautbois <jean-michel.hautbois@xxxxxxxxxxx>
> ---
>  drivers/mmc/core/mmc_ops.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
> index f51b5ba..91babaa 100644
> --- a/drivers/mmc/core/mmc_ops.c
> +++ b/drivers/mmc/core/mmc_ops.c
> @@ -458,6 +458,15 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
>  	if (!use_busy_signal)
>  		return 0;
>  
> +	/* WORKAROUND: for Sandisk eMMC cards, it might need certain delay
> +	 * before sending CMD13 after CMD6
> +	 * On SDIN5D1-2G MANFID is 0x45 and not 0x2 as specified in datasheet
> +	 */
> +	if (card->cid.manfid == CID_MANFID_SANDISK ||
> +		card->cid.manfid == 0x45) {
> +		msleep(1);
> +	}

If it's a general problem of Sandisk SDIN5D1-2G,
I think you need to verify this problem. And can you use the MMC_FIXUP() and QUIRK?

Best Regards,
Jaehoon Chung

> +
>  	/*
>  	 * CRC errors shall only be ignored in cases were CMD13 is used to poll
>  	 * to detect busy completion.
> 

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