mtd: nand: fsl_ifc: fix handing of bit flips in erased pages (d45e5316) · Commits · 戴 / test

drivers/mtd/nand/fsl_ifc_nand.c

+42 −35

Original line number	Diff line number	Diff line
		@@ -171,34 +171,6 @@ static void set_addr(struct mtd_info *mtd, int column, int page_addr, int oob)
		ifc_nand_ctrl->index += mtd->writesize;
		}

		static int is_blank(struct mtd_info *mtd, unsigned int bufnum)
		{
		struct nand_chip *chip = mtd_to_nand(mtd);
		struct fsl_ifc_mtd *priv = nand_get_controller_data(chip);
		u8 __iomem addr = priv->vbase + bufnum (mtd->writesize * 2);
		u32 __iomem mainarea = (u32 __iomem )addr;
		u8 __iomem *oob = addr + mtd->writesize;
		struct mtd_oob_region oobregion = { };
		int i, section = 0;

		for (i = 0; i < mtd->writesize / 4; i++) {
		if (__raw_readl(&mainarea[i]) != 0xffffffff)
		return 0;
		}

		mtd_ooblayout_ecc(mtd, section++, &oobregion);
		while (oobregion.length) {
		for (i = 0; i < oobregion.length; i++) {
		if (__raw_readb(&oob[oobregion.offset + i]) != 0xff)
		return 0;
		}

		mtd_ooblayout_ecc(mtd, section++, &oobregion);
		}

		return 1;
		}

		/* returns nonzero if entire page is blank */
		static int check_read_ecc(struct mtd_info mtd, struct fsl_ifc_ctrl ctrl,
		u32 *eccstat, unsigned int bufnum)
		@@ -274,16 +246,14 @@ static void fsl_ifc_run_command(struct mtd_info *mtd)
		if (errors == 15) {
		/*
		* Uncorrectable error.
		* OK only if the whole page is blank.
		* We'll check for blank pages later.
		*
		* We disable ECCER reporting due to...
		* erratum IFC-A002770 -- so report it now if we
		* see an uncorrectable error in ECCSTAT.
		*/
		if (!is_blank(mtd, bufnum))
		ctrl->nand_stat \|=
		IFC_NAND_EVTER_STAT_ECCER;
		break;
		ctrl->nand_stat \|= IFC_NAND_EVTER_STAT_ECCER;
		continue;
		}

		mtd->ecc_stats.corrected += errors;
		@@ -678,6 +648,39 @@ static int fsl_ifc_wait(struct mtd_info mtd, struct nand_chip chip)
		return nand_fsr \| NAND_STATUS_WP;
		}

		/*
		* The controller does not check for bitflips in erased pages,
		* therefore software must check instead.
		*/
		static int check_erased_page(struct nand_chip chip, u8 buf)
		{
		struct mtd_info *mtd = nand_to_mtd(chip);
		u8 *ecc = chip->oob_poi;
		const int ecc_size = chip->ecc.bytes;
		const int pkt_size = chip->ecc.size;
		int i, res, bitflips = 0;
		struct mtd_oob_region oobregion = { };

		mtd_ooblayout_ecc(mtd, 0, &oobregion);
		ecc += oobregion.offset;

		for (i = 0; i < chip->ecc.steps; ++i) {
		res = nand_check_erased_ecc_chunk(buf, pkt_size, ecc, ecc_size,
		NULL, 0,
		chip->ecc.strength);
		if (res < 0)
		mtd->ecc_stats.failed++;
		else
		mtd->ecc_stats.corrected += res;

		bitflips = max(res, bitflips);
		buf += pkt_size;
		ecc += ecc_size;
		}

		return bitflips;
		}

		static int fsl_ifc_read_page(struct mtd_info mtd, struct nand_chip chip,
		uint8_t *buf, int oob_required, int page)
		{
		@@ -689,8 +692,12 @@ static int fsl_ifc_read_page(struct mtd_info mtd, struct nand_chip chip,
		if (oob_required)
		fsl_ifc_read_buf(mtd, chip->oob_poi, mtd->oobsize);

		if (ctrl->nand_stat & IFC_NAND_EVTER_STAT_ECCER)
		dev_err(priv->dev, "NAND Flash ECC Uncorrectable Error\n");
		if (ctrl->nand_stat & IFC_NAND_EVTER_STAT_ECCER) {
		if (!oob_required)
		fsl_ifc_read_buf(mtd, chip->oob_poi, mtd->oobsize);

		return check_erased_page(chip, buf);
		}

		if (ctrl->nand_stat != IFC_NAND_EVTER_STAT_OPC)
		mtd->ecc_stats.failed++;

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