[MTD] [NAND] fix possible Ooops in rfc_from4

I found this while I was looking how the rs_lib is working.  The rs_decoder is
initialized _after_ the nand core code read the BBT table and _after_ the
partition table has been added.  The driver has a private BBT description
which is in located in flash data so we Ooops if there is a bit flip _or_ if a
bit flips while reading the partition table.

This patch moves the initialization of the rs_lib before the first possible
access by nand core.

Signed-off-by: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jörn Engel <joern@wh.fh-wedel.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 29 insertions, 21 deletions

diff --git a/drivers/mtd/nand/rtc_from4.c b/drivers/mtd/nand/rtc_from4.c
index 0f6ac250f434..26f88215bc47 100644
--- a/drivers/mtd/nand/rtc_from4.c
+++ b/drivers/mtd/nand/rtc_from4.c
@@ -478,6 +478,7 @@ static int __init rtc_from4_init(void)
         struct nand_chip *this;
         unsigned short bcr1, bcr2, wcr2;
         int i;
+        int ret;
 
         /* Allocate memory for MTD device structure and private data */
         rtc_from4_mtd = kmalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip), GFP_KERNEL);
@@ -537,6 +538,22 @@ static int __init rtc_from4_init(void)
         this->ecc.hwctl = rtc_from4_enable_hwecc;
         this->ecc.calculate = rtc_from4_calculate_ecc;
         this->ecc.correct = rtc_from4_correct_data;
+
+        /* We could create the decoder on demand, if memory is a concern.
+         * This way we have it handy, if an error happens
+         *
+         * Symbolsize is 10 (bits)
+         * Primitve polynomial is x^10+x^3+1
+         * first consecutive root is 0
+         * primitve element to generate roots = 1
+         * generator polinomial degree = 6
+         */
+        rs_decoder = init_rs(10, 0x409, 0, 1, 6);
+        if (!rs_decoder) {
+                printk(KERN_ERR "Could not create a RS decoder\n");
+                ret = -ENOMEM;
+                goto err_1;
+        }
 #else
         printk(KERN_INFO "rtc_from4_init: using software ECC detection.\n");
 
@@ -549,8 +566,8 @@ static int __init rtc_from4_init(void)
 
         /* Scan to find existence of the device */
         if (nand_scan(rtc_from4_mtd, RTC_FROM4_MAX_CHIPS)) {
-                kfree(rtc_from4_mtd);
-                return -ENXIO;
+                ret = -ENXIO;
+                goto err_2;
         }
 
         /* Perform 'device recovery' for each chip in case there was a power loss. */
@@ -566,28 +583,19 @@ static int __init rtc_from4_init(void)
 #endif
 
         /* Register the partitions */
-        add_mtd_partitions(rtc_from4_mtd, partition_info, NUM_PARTITIONS);
+        ret = add_mtd_partitions(rtc_from4_mtd, partition_info, NUM_PARTITIONS);
+        if (ret)
+                goto err_3;
 
-#ifdef RTC_FROM4_HWECC
-        /* We could create the decoder on demand, if memory is a concern.
-         * This way we have it handy, if an error happens
-         *
-         * Symbolsize is 10 (bits)
-         * Primitve polynomial is x^10+x^3+1
-         * first consecutive root is 0
-         * primitve element to generate roots = 1
-         * generator polinomial degree = 6
-         */
-        rs_decoder = init_rs(10, 0x409, 0, 1, 6);
-        if (!rs_decoder) {
-                printk(KERN_ERR "Could not create a RS decoder\n");
-                nand_release(rtc_from4_mtd);
-                kfree(rtc_from4_mtd);
-                return -ENOMEM;
-        }
-#endif
         /* Return happy */
         return 0;
+err_3:
+        nand_release(rtc_from4_mtd);
+err_2:
+        free_rs(rs_decoder);
+err_1:
+        kfree(rtc_from4_mtd);
+        return ret;
 }
 
 module_init(rtc_from4_init);