mmc: Retry some MMC cmds on failure

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@ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index a8a689f4f56e9bf2037a54fae038a62e8e82b443..006c9016a6d4bd317a51fcaff0b3bd95e5312ea5 100644 (file)
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -42,6 +42,15 @@ config ARM_PL180_MMCI
          If you have an ARM(R) platform with a Multimedia Card slot,
          say Y or M here.
 
+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 6278d1fa0c6c1d5ab488025462858727b127a9ff..26589b8771a892e8ecf524c14a47d95f7dde5529 100644 (file)
--- 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 a8901bffc7b6f852d0942018d7f9e1997d370c46..a9ebc880cb412e42f5b40d1e8525c13726083ef6 100644 (file)
--- 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 {