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>

1 files changed, 13 insertions, 21 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index d3545c9a792a..afbb80f4375a 100644
--- 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;
 }
 
 /**