On Mon, 7 May 2018 09:34:15 -0700 Jane Wan <[email protected]> wrote:
> Per ONFI specification (Rev. 4.0), if all parameter pages have invalid > CRC values, the bit-wise majority may be used to recover the contents of > the parameter pages from the parameter page copies present. > > Signed-off-by: Jane Wan <[email protected]> I never received patch 1 of this series. When you fix something in a commit, please resend the whole patchset, even if other patches haven't changed. > --- > drivers/mtd/nand/raw/nand_base.c | 41 > ++++++++++++++++++++++++++++++-------- > 1 file changed, 33 insertions(+), 8 deletions(-) > > diff --git a/drivers/mtd/nand/raw/nand_base.c > b/drivers/mtd/nand/raw/nand_base.c > index 72f3a89..48f2dec 100644 > --- a/drivers/mtd/nand/raw/nand_base.c > +++ b/drivers/mtd/nand/raw/nand_base.c > @@ -5086,15 +5086,18 @@ static int nand_flash_detect_ext_param_page(struct > nand_chip *chip, > return ret; > } > > +#define GET_BIT(bit, val) (((val) >> (bit)) & 0x01) > + > /* > * Check if the NAND chip is ONFI compliant, returns 1 if it is, 0 otherwise. > */ > static int nand_flash_detect_onfi(struct nand_chip *chip) > { > struct mtd_info *mtd = nand_to_mtd(chip); > - struct nand_onfi_params *p; > + struct nand_onfi_params *p = NULL; > char id[4]; > - int i, ret, val; > + int i, ret, val, pagesize; > + u8 *buf = NULL; > > /* Try ONFI for unknown chip or LP */ > ret = nand_readid_op(chip, 0x20, id, sizeof(id)); > @@ -5102,8 +5105,9 @@ 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); > - if (!p) > + pagesize = sizeof(*p); > + buf = kzalloc((pagesize * 3), GFP_KERNEL); Not sure why you have to add a new buf variable here, and pagesize is not needed either, just use sizeof(*p) directly. > + if (!buf) > return -ENOMEM; > > ret = nand_read_param_page_op(chip, 0, NULL, 0); > @@ -5113,7 +5117,8 @@ 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); > + p = (struct nand_onfi_params *)&buf[i*pagesize]; > + ret = nand_read_data_op(chip, p, pagesize, true); > if (ret) { > ret = 0; > goto free_onfi_param_page; > @@ -5126,8 +5131,27 @@ static int nand_flash_detect_onfi(struct nand_chip > *chip) > } > > if (i == 3) { > - pr_err("Could not find valid ONFI parameter page; aborting\n"); > - goto free_onfi_param_page; > + int j, k, l; > + u8 v, m; > + > + pr_err("Could not find valid ONFI parameter page\n"); > + pr_info("Recover ONFI params with bit-wise majority\n"); > + for (j = 0; j < pagesize; j++) { > + v = 0; > + for (k = 0; k < 8; k++) { > + m = 0; > + for (l = 0; l < 3; l++) > + m += GET_BIT(k, buf[l*pagesize + j]); > + if (m > 1) > + v |= BIT(k); > + } > + ((u8 *)p)[j] = v; > + } Can you move the bit-wise majority code in a separate function? > + if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) != > + le16_to_cpu(p->crc)) { > + pr_err("ONFI parameter recovery failed, aborting\n"); > + goto free_onfi_param_page; > + } > } > > /* Check version */ > @@ -5220,7 +5244,8 @@ static int nand_flash_detect_onfi(struct nand_chip > *chip) > sizeof(p->vendor)); > > free_onfi_param_page: > - kfree(p); > + if (buf != NULL) > + kfree(buf); kfree() already handles the buf == NULL case, no need to check it here. > return ret; > } >
