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Commit 3fc23898 authored by Richard Genoud's avatar Richard Genoud Committed by David Woodhouse
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[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: default avatarRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 08d79043

drivers/mtd/nand/atmel_nand.c

+6 −52
Original line number Diff line number Diff line
@@ -173,48 +173,6 @@ static void atmel_write_buf16(struct mtd_info *mtd, const u8 *buf, int len) 
	__raw_writesw(nand_chip->IO_ADDR_W, buf, len / 2);

}



/*

 * 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

 *
@@ -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: