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

[Jean-Michel Hautbois]

Hi Jaehoon,

> 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.

Yes

>>
>> 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?

Well, this is difficult to verify, I know that on all my SDIN5D1-2G I
have this MANFID different from what is defined by CID_MANFID_SANDISK.
How should I use MMC_FIXUP ? Like this ?
MMC_FIXUP("SEM02G", 0x45, CID_OEMID_ANY, add_quirk, MMC_QUIRK_INAND_CMD13) ?

If so, can I use :
if (card->quirks & MMC_QUIRK_INAND_CMD38)
    msleep(1);

In drivers/mmc/core/mmc_ops.c ?
Is this the good way ?

Thanks,
JM
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