mtd: nand: use read_oob() instead of cmdfunc() for bad block check

The nand_default_block_markbad() and scan_block_fast() use high
level APIs to get access to the BBM.

On the other hand, nand_block_bad (the default implementation of
->block_bad) calls the lower level ->cmdfunc hook.  This prevents
drivers from using ->ecc.read_oob() even if optimized read operation
is implemented.  Besides, some NAND controllers may protect the BBM
with ECC.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index d3545c9a792a7d6c216c262ec2671f3afd21c724..afbb80f4375a6b277f4f301edb855a9ab061e559 100644 (file)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -354,40 +354,32 @@ static void nand_read_buf16(struct mtd_info *mtd, uint8_t *buf, int len)
  */
 static int nand_block_bad(struct mtd_info *mtd, loff_t ofs)
 {
-       int page, res = 0, i = 0;
+       int page, page_end, res;
        struct nand_chip *chip = mtd_to_nand(mtd);
-       u16 bad;
+       u8 bad;
 
        if (chip->bbt_options & NAND_BBT_SCANLASTPAGE)
                ofs += mtd->erasesize - mtd->writesize;
 
        page = (int)(ofs >> chip->page_shift) & chip->pagemask;
+       page_end = page + (chip->bbt_options & NAND_BBT_SCAN2NDPAGE ? 2 : 1);
 
-       do {
-               if (chip->options & NAND_BUSWIDTH_16) {
-                       chip->cmdfunc(mtd, NAND_CMD_READOOB,
-                                       chip->badblockpos & 0xFE, page);
-                       bad = cpu_to_le16(chip->read_word(mtd));
-                       if (chip->badblockpos & 0x1)
-                               bad >>= 8;
-                       else
-                               bad &= 0xFF;
-               } else {
-                       chip->cmdfunc(mtd, NAND_CMD_READOOB, chip->badblockpos,
-                                       page);
-                       bad = chip->read_byte(mtd);
-               }
+       for (; page < page_end; page++) {
+               res = chip->ecc.read_oob(mtd, chip, page);
+               if (res)
+                       return res;
+
+               bad = chip->oob_poi[chip->badblockpos];
 
                if (likely(chip->badblockbits == 8))
                        res = bad != 0xFF;
                else
                        res = hweight8(bad) < chip->badblockbits;
-               ofs += mtd->writesize;
-               page = (int)(ofs >> chip->page_shift) & chip->pagemask;
-               i++;
-       } while (!res && i < 2 && (chip->bbt_options & NAND_BBT_SCAN2NDPAGE));
+               if (res)
+                       return res;
+       }
 
-       return res;
+       return 0;
 }
 
 /**