ENGR00287331-1 mmc: add delay after CMD6 befoer sending CMD13 for sandisk

- Some sandisk emmc cards need certain delay befor sending cmd13 after cmd6.
Original CR: ENGR174296 (commit: fd031f9)

Acked-by: Aisheng Dong <b29396@freescale.com>
Signed-off-by: Ryan QIAN <b32804@freescale.com>
(cherry picked from commit f942bf1db36355d46f38792601594949f3f2c71b)

diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 49f04bc9d0eb4cdfdd866b878fe840f0ae5e6e4c..83d17a9daea058d8708302bc3517de56886f4010 100644 (file)
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -440,6 +440,12 @@ 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
+        */
+       mdelay(1);
+
        /* Must check status to be sure of no errors */
        timeout = jiffies + msecs_to_jiffies(MMC_OPS_TIMEOUT_MS);
        do {