[MTD] [NAND] Bug on atmel_nand HW ECC : OOB info not correctly written

The functions that write the OOB info (on hardware ECC only) use the 
HW_SYNDROME method.

This is not correct : the start position is "pos = eccsize + chunk" and 
should be eccsize. So, the standard (nand_write_oob_std) function should 
be used. This patch corrects this by using NAND_ECC_HW instead of 
NAND_ECC_HW_SYNDROME.

This has only been tested on small pages nand flash.
(if anyone can test it on large pages that would be great).

kernel version : 2.6.27-rc2 (current git mtd-2.6)

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 6 insertions, 52 deletions

diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 3387e0d5076b..c98c1570a40b 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -174,48 +174,6 @@ static void atmel_write_buf16(struct mtd_info *mtd, const u8 *buf, int len)
 }
 
 /*
- * write oob for small pages
- */
-static int atmel_nand_write_oob_512(struct mtd_info *mtd,
-                struct nand_chip *chip, int page)
-{
-        int chunk = chip->ecc.bytes + chip->ecc.prepad + chip->ecc.postpad;
-        int eccsize = chip->ecc.size, length = mtd->oobsize;
-        int len, pos, status = 0;
-        const uint8_t *bufpoi = chip->oob_poi;
-
-        pos = eccsize + chunk;
-
-        chip->cmdfunc(mtd, NAND_CMD_SEQIN, pos, page);
-        len = min_t(int, length, chunk);
-        chip->write_buf(mtd, bufpoi, len);
-        bufpoi += len;
-        length -= len;
-        if (length > 0)
-                chip->write_buf(mtd, bufpoi, length);
-
-        chip->cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
-        status = chip->waitfunc(mtd, chip);
-
-        return status & NAND_STATUS_FAIL ? -EIO : 0;
-
-}
-
-/*
- * read oob for small pages
- */
-static int atmel_nand_read_oob_512(struct mtd_info *mtd,
-                struct nand_chip *chip, int page, int sndcmd)
-{
-        if (sndcmd) {
-                chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
-                sndcmd = 0;
-        }
-        chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
-        return sndcmd;
-}
-
-/*
  * Calculate HW ECC
  *
  * function called after a write
@@ -235,14 +193,14 @@ static int atmel_nand_calculate(struct mtd_info *mtd,
         /* get the first 2 ECC bytes */
         ecc_value = ecc_readl(host->ecc, PR);
 
-        ecc_code[eccpos[0]] = ecc_value & 0xFF;
-        ecc_code[eccpos[1]] = (ecc_value >> 8) & 0xFF;
+        ecc_code[0] = ecc_value & 0xFF;
+        ecc_code[1] = (ecc_value >> 8) & 0xFF;
 
         /* get the last 2 ECC bytes */
         ecc_value = ecc_readl(host->ecc, NPR) & ATMEL_ECC_NPARITY;
 
-        ecc_code[eccpos[2]] = ecc_value & 0xFF;
-        ecc_code[eccpos[3]] = (ecc_value >> 8) & 0xFF;
+        ecc_code[2] = ecc_value & 0xFF;
+        ecc_code[3] = (ecc_value >> 8) & 0xFF;
 
         return 0;
 }
@@ -476,14 +434,12 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
                         res = -EIO;
                         goto err_ecc_ioremap;
                 }
-                nand_chip->ecc.mode = NAND_ECC_HW_SYNDROME;
+                nand_chip->ecc.mode = NAND_ECC_HW;
                 nand_chip->ecc.calculate = atmel_nand_calculate;
                 nand_chip->ecc.correct = atmel_nand_correct;
                 nand_chip->ecc.hwctl = atmel_nand_hwctl;
                 nand_chip->ecc.read_page = atmel_nand_read_page;
                 nand_chip->ecc.bytes = 4;
-                nand_chip->ecc.prepad = 0;
-                nand_chip->ecc.postpad = 0;
         }
 
         nand_chip->chip_delay = 20;             /* 20us command delay time */
@@ -514,7 +470,7 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
                 goto err_scan_ident;
         }
 
-        if (nand_chip->ecc.mode == NAND_ECC_HW_SYNDROME) {
+        if (nand_chip->ecc.mode == NAND_ECC_HW) {
                 /* ECC is calculated for the whole page (1 step) */
                 nand_chip->ecc.size = mtd->writesize;
 
@@ -522,8 +478,6 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
                 switch (mtd->writesize) {
                 case 512:
                         nand_chip->ecc.layout = &atmel_oobinfo_small;
-                        nand_chip->ecc.read_oob = atmel_nand_read_oob_512;
-                        nand_chip->ecc.write_oob = atmel_nand_write_oob_512;
                         ecc_writel(host->ecc, MR, ATMEL_ECC_PAGESIZE_528);
                         break;
                 case 1024: