1 files changed, 43 insertions, 15 deletions

diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index 66f0405f7e53..b16f3cda97ff 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -9,7 +9,15 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+/*
+ * When the first attempt at device initialization fails, we may need to
+ * wait a little bit and retry. This timeout, by default 3 seconds, gives
+ * device time to start up. Required on BCM2708 and a few other chipsets.
+ */
+#define MTD_DEFAULT_TIMEOUT     3
+
 #include <linux/module.h>
+#include <linux/delay.h>
 #include <linux/fs.h>
 #include <linux/blkdev.h>
 #include <linux/bio.h>
@@ -209,10 +217,14 @@ static void block2mtd_free_device(struct block2mtd_dev *dev)
 }
 
 
-static struct block2mtd_dev *add_device(char *devname, int erase_size)
+static struct block2mtd_dev *add_device(char *devname, int erase_size,
+                int timeout)
 {
+#ifndef MODULE
+        int i;
+#endif
         const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
-        struct block_device *bdev;
+        struct block_device *bdev = ERR_PTR(-ENODEV);
         struct block2mtd_dev *dev;
         char *name;
 
@@ -225,15 +237,28 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size)
 
         /* Get a handle on the device */
         bdev = blkdev_get_by_path(devname, mode, dev);
-#ifndef MODULE
-        if (IS_ERR(bdev)) {
-
-                /* We might not have rootfs mounted at this point. Try
-                   to resolve the device name by other means. */
 
-                dev_t devt = name_to_dev_t(devname);
-                if (devt)
-                        bdev = blkdev_get_by_dev(devt, mode, dev);
+#ifndef MODULE
+        /*
+         * We might not have the root device mounted at this point.
+         * Try to resolve the device name by other means.
+         */
+        for (i = 0; IS_ERR(bdev) && i <= timeout; i++) {
+                dev_t devt;
+
+                if (i)
+                        /*
+                         * Calling wait_for_device_probe in the first loop
+                         * was not enough, sleep for a bit in subsequent
+                         * go-arounds.
+                         */
+                        msleep(1000);
+                wait_for_device_probe();
+
+                devt = name_to_dev_t(devname);
+                if (!devt)
+                        continue;
+                bdev = blkdev_get_by_dev(devt, mode, dev);
         }
 #endif
 
@@ -280,6 +305,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size)
                 /* Device didn't get added, so free the entry */
                 goto err_destroy_mutex;
         }
+
         list_add(&dev->list, &blkmtd_device_list);
         pr_info("mtd%d: [%s] erase_size = %dKiB [%d]\n",
                 dev->mtd.index,
@@ -348,16 +374,19 @@ static inline void kill_final_newline(char *str)
 
 #ifndef MODULE
 static int block2mtd_init_called = 0;
-static char block2mtd_paramline[80 + 12]; /* 80 for device, 12 for erase size */
+/* 80 for device, 12 for erase size */
+static char block2mtd_paramline[80 + 12];
 #endif
 
 static int block2mtd_setup2(const char *val)
 {
-        char buf[80 + 12]; /* 80 for device, 12 for erase size */
+        /* 80 for device, 12 for erase size, 80 for name, 8 for timeout */
+        char buf[80 + 12 + 80 + 8];
         char *str = buf;
         char *token[2];
         char *name;
         size_t erase_size = PAGE_SIZE;
+        unsigned long timeout = MTD_DEFAULT_TIMEOUT;
         int i, ret;
 
         if (strnlen(val, sizeof(buf)) >= sizeof(buf)) {
@@ -395,7 +424,7 @@ static int block2mtd_setup2(const char *val)
                 }
         }
 
-        add_device(name, erase_size);
+        add_device(name, erase_size, timeout);
 
         return 0;
 }
@@ -463,8 +492,7 @@ static void block2mtd_exit(void)
         }
 }
 
-
-module_init(block2mtd_init);
+late_initcall(block2mtd_init);
 module_exit(block2mtd_exit);
 
 MODULE_LICENSE("GPL");