Messages in this thread Patch in this message | | | From | Jean-Michel Hautbois <> | Subject | [PATCH] mmc: Add delay between CMD6 and CMD13 for Sandisk eMMC cards | Date | Tue, 9 Sep 2014 14:26:54 +0200 |
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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.
Signed-off-by: Jean-Michel Hautbois <jean-michel.hautbois@vodalys.com> --- 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); + } + /* * CRC errors shall only be ignored in cases were CMD13 is used to poll * to detect busy completion. -- 2.0.4
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