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