mtd: rawnand: use bit-wise majority to recover the ONFI param page (39138c1f) · Commits · 戴 / test

drivers/mtd/nand/raw/nand_base.c

+47 −5

Original line number	Diff line number	Diff line
		@@ -5086,6 +5086,37 @@ ext_out:
		return ret;
		}

		/*
		* Recover data with bit-wise majority
		*/
		static void nand_bit_wise_majority(const void **srcbufs,
		unsigned int nsrcbufs,
		void *dstbuf,
		unsigned int bufsize)
		{
		int i, j, k;

		for (i = 0; i < bufsize; i++) {
		u8 val = 0;

		for (j = 0; j < 8; j++) {
		unsigned int cnt = 0;

		for (k = 0; k < nsrcbufs; k++) {
		const u8 *srcbuf = srcbufs[k];

		if (srcbuf[i] & BIT(j))
		cnt++;
		}

		if (cnt > nsrcbufs / 2)
		val \|= BIT(j);
		}

		((u8 *)dstbuf)[i] = val;
		}
		}

		/*
		* Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise.
		*/
		@@ -5102,7 +5133,7 @@ static int nand_flash_detect_onfi(struct nand_chip *chip)
		return 0;

		/* ONFI chip: allocate a buffer to hold its parameter page */
		p = kzalloc(sizeof(*p), GFP_KERNEL);
		p = kzalloc((sizeof(p) 3), GFP_KERNEL);
		if (!p)
		return -ENOMEM;

		@@ -5113,22 +5144,33 @@ static int nand_flash_detect_onfi(struct nand_chip *chip)
		}

		for (i = 0; i < 3; i++) {
		ret = nand_read_data_op(chip, p, sizeof(*p), true);
		ret = nand_read_data_op(chip, &p[i], sizeof(*p), true);
		if (ret) {
		ret = 0;
		goto free_onfi_param_page;
		}

		if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
		if (onfi_crc16(ONFI_CRC_BASE, (u8 *)&p[i], 254) ==
		le16_to_cpu(p->crc)) {
		if (i)
		memcpy(p, &p[i], sizeof(*p));
		break;
		}
		}

		if (i == 3) {
		pr_err("Could not find valid ONFI parameter page; aborting\n");
		const void *srcbufs[3] = {p, p + 1, p + 2};

		pr_warn("Could not find a valid ONFI parameter page, trying bit-wise majority to recover it\n");
		nand_bit_wise_majority(srcbufs, ARRAY_SIZE(srcbufs), p,
		sizeof(*p));

		if (onfi_crc16(ONFI_CRC_BASE, (u8 *)p, 254) !=
		le16_to_cpu(p->crc)) {
		pr_err("ONFI parameter recovery failed, aborting\n");
		goto free_onfi_param_page;
		}
		}

		/* Check version */
		val = le16_to_cpu(p->revision);

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