ANDROID: mmc: sd: Add new CONFIG_MMC_PARANOID_SD_INIT for enabling retries during...

Change-Id: I4e6b9d9a3600d7efbee1d8379e45db11c57827f2
Signed-off-by: San Mehat <san@google.com>

diff --git a/drivers/mmc/core/Kconfig b/drivers/mmc/core/Kconfig
index 42e89060cd41ecb766dbc3c4b2c98b6037decae1..0b004586c80341ec7bb43a25b113ab8039aed9e6 100644 (file)
--- a/drivers/mmc/core/Kconfig
+++ b/drivers/mmc/core/Kconfig
@@ -80,3 +80,10 @@ config MMC_TEST
          This driver is only of interest to those developing or
          testing a host driver. Most people should say N here.
 
+config MMC_PARANOID_SD_INIT
+       bool "Enable paranoid SD card initialization (EXPERIMENTAL)"
+       help
+         If you say Y here, the MMC layer will be extra paranoid
+         about re-trying SD init requests. This can be a useful
+         work-around for buggy controllers and hardware. Enable
+         if you are experiencing issues with SD detection.

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 4fd1620b732d090311f845f6d138c80187517519..e85524cc3659191bd8bd5feceac30d48a34e2f3b 100644 (file)
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -834,6 +834,9 @@ int mmc_sd_setup_card(struct mmc_host *host, struct mmc_card *card,
        bool reinit)
 {
        int err;
+#ifdef CONFIG_MMC_PARANOID_SD_INIT
+       int retries;
+#endif
 
        if (!reinit) {
                /*
@@ -860,7 +863,26 @@ int mmc_sd_setup_card(struct mmc_host *host, struct mmc_card *card,
                /*
                 * Fetch switch information from card.
                 */
+#ifdef CONFIG_MMC_PARANOID_SD_INIT
+               for (retries = 1; retries <= 3; retries++) {
+                       err = mmc_read_switch(card);
+                       if (!err) {
+                               if (retries > 1) {
+                                       printk(KERN_WARNING
+                                              "%s: recovered\n",
+                                              mmc_hostname(host));
+                               }
+                               break;
+                       } else {
+                               printk(KERN_WARNING
+                                      "%s: read switch failed (attempt %d)\n",
+                                      mmc_hostname(host), retries);
+                       }
+               }
+#else
                err = mmc_read_switch(card);
+#endif
+
                if (err)
                        return err;
        }