[MTD] NAND: Fix broken bad block table scan

Make the bad block table search functional again

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index c85c69d..5ac2d29 100644 (file)
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -6,7 +6,7 @@
  *   
  *  Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de)
  *
- * $Id: nand_bbt.c,v 1.31 2005/02/16 17:09:36 dedekind Exp $
+ * $Id: nand_bbt.c,v 1.33 2005/06/14 15:47:56 gleixner Exp $
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -80,14 +80,14 @@ static int check_pattern (uint8_t *buf, int len, int paglen, struct nand_bbt_des
        int i, end = 0;
        uint8_t *p = buf;
 
+       end = paglen + td->offs;
        if (td->options & NAND_BBT_SCANEMPTY) {
-               end = paglen + td->offs;
                for (i = 0; i < end; i++) {
                        if (p[i] != 0xff)
                                return -1;
                }
-               p += end;
        }       
+       p += end;
        
        /* Compare the pattern */
        for (i = 0; i < td->len; i++) {
@@ -106,6 +106,32 @@ static int check_pattern (uint8_t *buf, int len, int paglen, struct nand_bbt_des
        return 0;
 }
 
+/** 
+ * check_short_pattern - [GENERIC] check if a pattern is in the buffer
+ * @buf:       the buffer to search
+ * @len:       the length of buffer to search
+ * @paglen:    the pagelength
+ * @td:                search pattern descriptor
+ *
+ * Check for a pattern at the given place. Used to search bad block
+ * tables and good / bad block identifiers. Same as check_pattern, but 
+ * no optional empty check and the pattern is expected to start
+ * at offset 0.
+ *
+*/
+static int check_short_pattern (uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
+{
+       int i;
+       uint8_t *p = buf;
+
+       /* Compare the pattern */
+       for (i = 0; i < td->len; i++) {
+               if (p[i] != td->pattern[i])
+                       return -1;
+       }
+       return 0;
+}
+
 /**
  * read_bbt - [GENERIC] Read the bad block table starting from page
  * @mtd:       MTD device structure
@@ -316,18 +342,25 @@ static int create_bbt (struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr
                                                        readlen, &retlen, &buf[0]);
                                if (ret)
                                        return ret;
-                       }
-                       if (check_pattern (&buf[j * scanlen], scanlen, mtd->oobblock, bd)) {
-                               this->bbt[i >> 3] |= 0x03 << (i & 0x6);
-                               printk (KERN_WARNING "Bad eraseblock %d at 0x%08x\n", 
-                                       i >> 1, (unsigned int) from);
-                               break;
+
+                               if (check_short_pattern (&buf[j * scanlen], scanlen, mtd->oobblock, bd)) {
+                                       this->bbt[i >> 3] |= 0x03 << (i & 0x6);
+                                       printk (KERN_WARNING "Bad eraseblock %d at 0x%08x\n", 
+                                               i >> 1, (unsigned int) from);
+                                       break;
+                               }
+                       } else {
+                               if (check_pattern (&buf[j * scanlen], scanlen, mtd->oobblock, bd)) {
+                                       this->bbt[i >> 3] |= 0x03 << (i & 0x6);
+                                       printk (KERN_WARNING "Bad eraseblock %d at 0x%08x\n", 
+                                               i >> 1, (unsigned int) from);
+                                       break;
+                               }
                        }
                }
                i += 2;
                from += (1 << this->bbt_erase_shift);
        }
-
        return 0;
 }