[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>

diff --git a/drivers/mtd/nand/rtc_from4.c b/drivers/mtd/nand/rtc_from4.c
index 0f6ac250f434909708bb6a5206ceb1b5c6ae3fad..26f88215bc47d48c12ff9768da72829366d4ac76 100644 (file)
--- 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);