Hi, On 09/22/2014 02:48 AM, Pavel Machek wrote: > On Mon 2014-09-15 19:44:28, Jaehoon Chung wrote: >> On 09/15/2014 07:08 PM, Jean-Michel Hautbois wrote: >>> 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 ? >> >> I think you need to explain why delay is need. >> i didn't have same card, but it might be your host controller or other problem. > > Datasheet says it is needed, so we need to do the delay. > > Adding pointer to the datasheet (page, chapter) to the comment might be good idea. It's good. Then i think good that it will add the delay with the MMC_FIXUP and QUIRK. Best Regards, Jaehoon Chung > > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html