From b38576667cdcf7a646843b07666faae11cc63e9c Mon Sep 17 00:00:00 2001
From: Bo Shen <voice.shen@atmel.com>
Date: Thu, 12 Jun 2014 15:58:45 +0800
Subject: mtd: atmel_nand: make ecc parameters same as definition

If the ecc parameter is not the same as definition, when the
mtd core check these parameters, it will give the error result.

Take the following as an example:

Calculate how many bits can be corrected in one page.
According to the ecc parameters definition,

one page correct bits = (mtd->writesize * ecc->strength) / ecc->size

take the following use case as an example:
mtd->writesize = 2048 bytes
ecc->strength = 4 bytes (for 512 bytes)

before this patch, the ecc->size = 2048, so the result is 4 bytes.
after this patch, the ecc->size = 512, so the result is 16 bytes.

So, align the ecc parameters the same as definition to correct
this kind of error.

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 4ce181a..4f5348f 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -861,12 +861,11 @@ static int pmecc_correction(struct mtd_info *mtd, u32 pmecc_stat, uint8_t *buf,
 {
 	struct nand_chip *nand_chip = mtd->priv;
 	struct atmel_nand_host *host = nand_chip->priv;
-	int i, err_nbr, eccbytes;
+	int i, err_nbr;
 	uint8_t *buf_pos;
 	int total_err = 0;
 
-	eccbytes = nand_chip->ecc.bytes;
-	for (i = 0; i < eccbytes; i++)
+	for (i = 0; i < nand_chip->ecc.total; i++)
 		if (ecc[i] != 0xff)
 			goto normal_check;
 	/* Erased page, return OK */
@@ -928,7 +927,7 @@ static int atmel_nand_pmecc_read_page(struct mtd_info *mtd,
 	struct nand_chip *chip, uint8_t *buf, int oob_required, int page)
 {
 	struct atmel_nand_host *host = chip->priv;
-	int eccsize = chip->ecc.size;
+	int eccsize = chip->ecc.size * chip->ecc.steps;
 	uint8_t *oob = chip->oob_poi;
 	uint32_t *eccpos = chip->ecc.layout->eccpos;
 	uint32_t stat;
@@ -1169,8 +1168,7 @@ static int atmel_pmecc_nand_init_params(struct platform_device *pdev,
 		goto err;
 	}
 
-	/* ECC is calculated for the whole page (1 step) */
-	nand_chip->ecc.size = mtd->writesize;
+	nand_chip->ecc.size = sector_size;
 
 	/* set ECC page size and oob layout */
 	switch (mtd->writesize) {
@@ -1185,18 +1183,20 @@ static int atmel_pmecc_nand_init_params(struct platform_device *pdev,
 		host->pmecc_index_of = host->pmecc_rom_base +
 			host->pmecc_lookup_table_offset;
 
-		nand_chip->ecc.steps = 1;
+		nand_chip->ecc.steps = host->pmecc_sector_number;
 		nand_chip->ecc.strength = cap;
-		nand_chip->ecc.bytes = host->pmecc_bytes_per_sector *
+		nand_chip->ecc.bytes = host->pmecc_bytes_per_sector;
+		nand_chip->ecc.total = host->pmecc_bytes_per_sector *
 				       host->pmecc_sector_number;
-		if (nand_chip->ecc.bytes > mtd->oobsize - 2) {
+		if (nand_chip->ecc.total > mtd->oobsize - 2) {
 			dev_err(host->dev, "No room for ECC bytes\n");
 			err_no = -EINVAL;
 			goto err;
 		}
 		pmecc_config_ecc_layout(&atmel_pmecc_oobinfo,
 					mtd->oobsize,
-					nand_chip->ecc.bytes);
+					nand_chip->ecc.total);
+
 		nand_chip->ecc.layout = &atmel_pmecc_oobinfo;
 		break;
 	case 512:
-- 
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