[U-Boot] [PATCH v2 23/26] mmc: Retry some MMC cmds on failure

[Jean-Jacques Hiblot]

From: Kishon Vijay Abraham I <kishon 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 a few time
as done in Linux kernel.
Similarly, it is seen that MMC_CMD_SET_BLOCKLEN may fail on first
attempt, therefore retry this cmd a few times as done in kernel.

To make it clear that those are optionnal workarounds, a new Kconfig
option 'MMC_QUIRKS' is added (enabled by default).

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/Kconfig |  9 +++++++++
 drivers/mmc/mmc.c   | 41 +++++++++++++++++++++++++++++++++++++++--
 include/mmc.h       |  4 ++++
 3 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 3d577e0..78e58d4 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -33,6 +33,15 @@ config SPL_DM_MMC
 
 if MMC
 
+config MMC_QUIRKS
+	bool "Enable quirks"
+	default y
+	help
+	  Some cards and hosts may sometimes behave unexpectedly (quirks).
+	  This option enable workarounds to handle those quirks. Some of them
+	  are enabled by default, other may require additionnal flags or are
+	  enabled by the host driver.
+
 config MMC_VERBOSE
 	bool "Output more information about the MMC"
 	default y
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index c5eaeaf..6d1bf94 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -279,6 +279,7 @@ int mmc_send_status(struct mmc *mmc, int timeout)
 int mmc_set_blocklen(struct mmc *mmc, int len)
 {
 	struct mmc_cmd cmd;
+	int err;
 
 	if (mmc->ddr_mode)
 		return 0;
@@ -287,7 +288,24 @@ int mmc_set_blocklen(struct mmc *mmc, int len)
 	cmd.resp_type = MMC_RSP_R1;
 	cmd.cmdarg = len;
 
-	return mmc_send_cmd(mmc, &cmd, NULL);
+	err = mmc_send_cmd(mmc, &cmd, NULL);
+
+#ifdef CONFIG_MMC_QUIRKS
+	if (err && (mmc->quirks & MMC_QUIRK_RETRY_SET_BLOCKLEN)) {
+		int retries = 4;
+		/*
+		 * It has been seen that SET_BLOCKLEN may fail on the first
+		 * attempt, let's try a few more time
+		 */
+		do {
+			err = mmc_send_cmd(mmc, &cmd, NULL);
+			if (!err)
+				break;
+		} while (retries--);
+	}
+#endif
+
+	return err;
 }
 
 static int mmc_read_blocks(struct mmc *mmc, void *dst, lbaint_t start,
@@ -1881,7 +1899,6 @@ 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;
 	}
@@ -1895,6 +1912,21 @@ static int mmc_startup(struct mmc *mmc)
 
 	err = mmc_send_cmd(mmc, &cmd, NULL);
 
+#ifdef CONFIG_MMC_QUIRKS
+	if (err && (mmc->quirks & MMC_QUIRK_RETRY_SEND_CID)) {
+		int retries = 4;
+		/*
+		 * It has been seen that SEND_CID may fail on the first
+		 * attempt, let's try a few more time
+		 */
+		do {
+			err = mmc_send_cmd(mmc, &cmd, NULL);
+			if (!err)
+				break;
+		} while (retries--);
+	}
+#endif
+
 	if (err)
 		return err;
 
@@ -2239,6 +2271,11 @@ int mmc_start_init(struct mmc *mmc)
 	if (err)
 		return err;
 
+#ifdef CONFIG_MMC_QUIRKS
+	mmc->quirks = MMC_QUIRK_RETRY_SET_BLOCKLEN |
+		      MMC_QUIRK_RETRY_SEND_CID;
+#endif
+
 	err = mmc_power_cycle(mmc);
 	if (err) {
 		/*
diff --git a/include/mmc.h b/include/mmc.h
index a8901bf..a9ebc88 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -306,6 +306,9 @@ static inline bool mmc_is_tuning_cmd(uint cmdidx)
 #define ENHNCD_SUPPORT		(0x2)
 #define PART_ENH_ATTRIB		(0x1f)
 
+#define MMC_QUIRK_RETRY_SEND_CID	BIT(0)
+#define MMC_QUIRK_RETRY_SET_BLOCKLEN	BIT(1)
+
 enum mmc_voltage {
 	MMC_SIGNAL_VOLTAGE_000 = 0,
 	MMC_SIGNAL_VOLTAGE_120,
@@ -591,6 +594,7 @@ struct mmc {
 				  * operating mode due to limitations when
 				  * accessing the boot partitions
 				  */
+	u32 quirks;
 };
 
 struct mmc_hwpart_conf {
-- 
1.9.1