[U-Boot] [PATCH 22/22] mmc: Retry some MMC cmds on failure

[Jean-Jacques Hiblot]

From: Vignesh R <vigneshr at ti.com>

With certain SD cards like Kingston 8GB/16GB UHS card, it is seen that
MMC_CMD_ALL_SEND_CID cmd fails on first attempt, but succeeds
subsequently. Therefore, retry MMC_CMD_ALL_SEND_CID cmd at least thrice
as done in Linux kernel.
Similarly, it is seen that MMC_CMD_SET_BLOCKLEN may fail on first
attempt, therefore retry this cmd five times as done in kernel.

Signed-off-by: Vignesh R <vigneshr at ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon at ti.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot at ti.com>
---
 drivers/mmc/mmc.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index c7dda64..49edf52 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -275,6 +275,8 @@ int mmc_send_status(struct mmc *mmc, int timeout)
 int mmc_set_blocklen(struct mmc *mmc, int len)
 {
 	struct mmc_cmd cmd;
+	int retries = 5;
+	int err;
 
 	if (mmc->ddr_mode)
 		return 0;
@@ -282,8 +284,13 @@ int mmc_set_blocklen(struct mmc *mmc, int len)
 	cmd.cmdidx = MMC_CMD_SET_BLOCKLEN;
 	cmd.resp_type = MMC_RSP_R1;
 	cmd.cmdarg = len;
+	do {
+		err = mmc_send_cmd(mmc, &cmd, NULL);
+		if (!err)
+			break;
+	} while (retries--);
 
-	return mmc_send_cmd(mmc, &cmd, NULL);
+	return err;
 }
 
 static int mmc_read_blocks(struct mmc *mmc, void *dst, lbaint_t start,
@@ -1867,6 +1874,7 @@ static int mmc_startup(struct mmc *mmc)
 	u64 cmult, csize;
 	struct mmc_cmd cmd;
 	struct blk_desc *bdesc;
+	int retries = 3;
 
 #ifdef CONFIG_MMC_SPI_CRC_ON
 	if (mmc_host_is_spi(mmc)) { /* enable CRC check for spi */
@@ -1874,7 +1882,6 @@ static int mmc_startup(struct mmc *mmc)
 		cmd.resp_type = MMC_RSP_R1;
 		cmd.cmdarg = 1;
 		err = mmc_send_cmd(mmc, &cmd, NULL);
-
 		if (err)
 			return err;
 	}
@@ -1886,7 +1893,9 @@ static int mmc_startup(struct mmc *mmc)
 	cmd.resp_type = MMC_RSP_R2;
 	cmd.cmdarg = 0;
 
-	err = mmc_send_cmd(mmc, &cmd, NULL);
+	do {
+		err = mmc_send_cmd(mmc, &cmd, NULL);
+	} while (err && retries-- > 0);
 
 	if (err)
 		return err;
-- 
1.9.1