openwrt/target/linux/generic/patches-3.12/441-block2mtd_probe.patch

--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -10,6 +10,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/module.h>
+#include <linux/delay.h>
 #include <linux/fs.h>
 #include <linux/blkdev.h>
 #include <linux/bio.h>
@@ -210,13 +211,14 @@ static void block2mtd_free_device(struct
 
 
 /* FIXME: ensure that mtd->size % erase_size == 0 */
-static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname)
+static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname, int timeout)
 {
 	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;
 	struct mtd_partition *part;
 	char *name;
+	int i;
 
 	if (!devname)
 		return NULL;
@@ -227,15 +229,20 @@ static struct block2mtd_dev *add_device(
 
 	/* Get a handle on the device */
 	bdev = blkdev_get_by_path(devname, mode, dev);
+
 #ifndef MODULE
-	if (IS_ERR(bdev)) {
+	for (i = 0; IS_ERR(bdev) && i <= timeout; i++) {
+		dev_t devt;
 
-		/* We might not have rootfs mounted at this point. Try
-		   to resolve the device name by other means. */
+		if (i)
+			msleep(1000);
+		wait_for_device_probe();
+
+		devt = name_to_dev_t(devname);
+		if (!devt)
+			continue;
 
-		dev_t devt = name_to_dev_t(devname);
-		if (devt)
-			bdev = blkdev_get_by_dev(devt, mode, dev);
+		bdev = blkdev_get_by_dev(devt, mode, dev);
 	}
 #endif
 
@@ -354,11 +361,12 @@ static char block2mtd_paramline[80 + 12]
 
 static int block2mtd_setup2(const char *val)
 {
-	char buf[80 + 12 + 80]; /* 80 for device, 12 for erase size, 80 for name */
+	char buf[80 + 12 + 80 + 8]; /* 80 for device, 12 for erase size, 80 for name, 8 for timeout */
 	char *str = buf;
-	char *token[3];
+	char *token[4];
 	char *name;
 	size_t erase_size = PAGE_SIZE;
+	unsigned long timeout = 0;
 	int i, ret;
 
 	if (strnlen(val, sizeof(buf)) >= sizeof(buf)) {
@@ -369,7 +377,7 @@ static int block2mtd_setup2(const char *
 	strcpy(str, val);
 	kill_final_newline(str);
 
-	for (i = 0; i < 3; i++)
+	for (i = 0; i < 4; i++)
 		token[i] = strsep(&str, ",");
 
 	if (str) {
@@ -398,7 +406,10 @@ static int block2mtd_setup2(const char *
 	if (token[2] && (strlen(token[2]) + 1 > 80))
 		pr_err("mtd device name too long\n");
 
-	add_device(name, erase_size, token[2]);
+	if (token[3] && kstrtoul(token[3], 0, &timeout))
+		pr_err("invalid timeout\n");
+
+	add_device(name, erase_size, token[2], timeout);
 
 	return 0;
 }
@@ -432,7 +443,7 @@ static int block2mtd_setup(const char *v
 
 
 module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
-MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>[,<name>]]\"");
+MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>[,<name>[,<timeout>]]]\"");
 
 static int __init block2mtd_init(void)
 {
@@ -466,7 +477,7 @@ static void block2mtd_exit(void)
 }
 
 
-module_init(block2mtd_init);
+late_initcall(block2mtd_init);
 module_exit(block2mtd_exit);
 
 MODULE_LICENSE("GPL");