mmc: retry CMD1 in mmc_send_op_cond() until the eMMC is ready

According to eMMC specification v5.1 section 6.4.3, we should issue
CMD1 repeatedly in the idle state until the eMMC is ready even if
mmc_send_op_cond() send CMD1 with argument = 0. Otherwise some eMMC
devices seems to enter the inactive mode after mmc_complete_op_cond()
issued CMD0 when the eMMC device is busy.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 620bb930640fc6df2ec41cbd1668504ed7cd98a0..725a36799d355ae7b3dd922f68e54495cf2b480e 100644 (file)
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -669,12 +669,15 @@ static int mmc_send_op_cond_iter(struct mmc *mmc, int use_arg)
 static int mmc_send_op_cond(struct mmc *mmc)
 {
        int err, i;
+       int timeout = 1000;
+       uint start;
 
        /* Some cards seem to need this */
        mmc_go_idle(mmc);
 
+       start = get_timer(0);
        /* Asking to the card its capabilities */
-       for (i = 0; i < 2; i++) {
+       for (i = 0; ; i++) {
                err = mmc_send_op_cond_iter(mmc, i != 0);
                if (err)
                        return err;
@@ -682,6 +685,10 @@ static int mmc_send_op_cond(struct mmc *mmc)
                /* exit if not busy (flag seems to be inverted) */
                if (mmc->ocr & OCR_BUSY)
                        break;
+
+               if (get_timer(start) > timeout)
+                       return -ETIMEDOUT;
+               udelay(100);
        }
        mmc->op_cond_pending = 1;
        return 0;