From 753e0139e5569946056a8d5960111665a7f8f6f1 Mon Sep 17 00:00:00 2001 From: Armando Visconti Date: Wed, 7 Mar 2012 17:00:54 +0530 Subject: [PATCH] mtd: fsmc: Improve the fsmc_correct_data() routine This patch improves the error correction routine for bch8 - Loop only up to number of errors detected - Improve the error index calculation procedure Additionally, it also renames the "correct" routine to indicate that it is bch8 specific Signed-off-by: Armando Visconti Signed-off-by: Vipin Kumar Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/nand/fsmc_nand.c | 38 ++++++++++++++++-------------------- 1 file changed, 17 insertions(+), 21 deletions(-) diff --git a/drivers/mtd/nand/fsmc_nand.c b/drivers/mtd/nand/fsmc_nand.c index cfe15a6f29d0..5b217f2a31b7 100644 --- a/drivers/mtd/nand/fsmc_nand.c +++ b/drivers/mtd/nand/fsmc_nand.c @@ -587,7 +587,7 @@ static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip, } /* - * fsmc_correct_data + * fsmc_bch8_correct_data * @mtd: mtd info structure * @dat: buffer of read data * @read_ecc: ecc read from device spare area @@ -596,7 +596,7 @@ static int fsmc_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip, * calc_ecc is a 104 bit information containing maximum of 8 error * offset informations of 13 bits each in 512 bytes of read data. */ -static int fsmc_correct_data(struct mtd_info *mtd, uint8_t *dat, +static int fsmc_bch8_correct_data(struct mtd_info *mtd, uint8_t *dat, uint8_t *read_ecc, uint8_t *calc_ecc) { struct fsmc_nand_data *host = container_of(mtd, @@ -605,8 +605,8 @@ static int fsmc_correct_data(struct mtd_info *mtd, uint8_t *dat, struct fsmc_regs *regs = host->regs_va; unsigned int bank = host->bank; uint32_t err_idx[8]; - uint64_t ecc_data[2]; uint32_t num_err, i; + uint32_t ecc1, ecc2, ecc3, ecc4; num_err = (readl(®s->bank_regs[bank].sts) >> 10) & 0xF; @@ -642,9 +642,6 @@ static int fsmc_correct_data(struct mtd_info *mtd, uint8_t *dat, return -EBADMSG; } - /* The calculated ecc is actually the correction index in data */ - memcpy(ecc_data, calc_ecc, chip->ecc.bytes); - /* * ------------------- calc_ecc[] bit wise -----------|--13 bits--| * |---idx[7]--|--.....-----|---idx[2]--||---idx[1]--||---idx[0]--| @@ -654,20 +651,19 @@ static int fsmc_correct_data(struct mtd_info *mtd, uint8_t *dat, * uint64_t array and error offset indexes are populated in err_idx * array */ - for (i = 0; i < 8; i++) { - if (i == 4) { - err_idx[4] = ((ecc_data[1] & 0x1) << 12) | ecc_data[0]; - ecc_data[1] >>= 1; - continue; - } - err_idx[i] = (ecc_data[i/4] & 0x1FFF); - ecc_data[i/4] >>= 13; - } - - num_err = (readl(®s->bank_regs[bank].sts) >> 10) & 0xF; - - if (num_err == 0xF) - return -EBADMSG; + ecc1 = readl(®s->bank_regs[bank].ecc1); + ecc2 = readl(®s->bank_regs[bank].ecc2); + ecc3 = readl(®s->bank_regs[bank].ecc3); + ecc4 = readl(®s->bank_regs[bank].sts); + + err_idx[0] = (ecc1 >> 0) & 0x1FFF; + err_idx[1] = (ecc1 >> 13) & 0x1FFF; + err_idx[2] = (((ecc2 >> 0) & 0x7F) << 6) | ((ecc1 >> 26) & 0x3F); + err_idx[3] = (ecc2 >> 7) & 0x1FFF; + err_idx[4] = (((ecc3 >> 0) & 0x1) << 12) | ((ecc2 >> 20) & 0xFFF); + err_idx[5] = (ecc3 >> 1) & 0x1FFF; + err_idx[6] = (ecc3 >> 14) & 0x1FFF; + err_idx[7] = (((ecc4 >> 16) & 0xFF) << 5) | ((ecc3 >> 27) & 0x1F); i = 0; while (num_err--) { @@ -829,7 +825,7 @@ static int __init fsmc_nand_probe(struct platform_device *pdev) if (AMBA_REV_BITS(host->pid) >= 8) { nand->ecc.read_page = fsmc_read_page_hwecc; nand->ecc.calculate = fsmc_read_hwecc_ecc4; - nand->ecc.correct = fsmc_correct_data; + nand->ecc.correct = fsmc_bch8_correct_data; nand->ecc.bytes = 13; } else { nand->ecc.calculate = fsmc_read_hwecc_ecc1; -- 2.30.2