Hi, The following is the reposting of patch with v2 version indication based on comment on "[PATCH 1/2]" (also in the attachment).
Subject: [PATCH v2 2/2] mtd: rawnand: fsl_ifc: use bit-wise majority to recover the contents of ONFI parameter 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]> --- drivers/mtd/nand/raw/nand_base.c | 36 ++++++++++++++++++++++++++++++------ 1 file changed, 30 insertions(+), 6 deletions(-) diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index 72f3a89..464c4fb 100644 --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -5086,6 +5086,8 @@ 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. */ @@ -5094,7 +5096,8 @@ static int nand_flash_detect_onfi(struct nand_chip *chip) struct mtd_info *mtd = nand_to_mtd(chip); struct nand_onfi_params *p; char id[4]; - int i, ret, val; + int i, ret, val, pagesize; + u8 *buf; /* 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); + 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; + } + 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 */ -- 1.7.9.5 Thanks. Jane > -----Original Message----- > From: Boris Brezillon [mailto:[email protected]] > Sent: Wednesday, May 02, 2018 3:32 AM > To: Wan, Jane (Nokia - US/Sunnyvale) <[email protected]> > Cc: [email protected]; [email protected]; Bos, Ties (Nokia - > US/Sunnyvale) <[email protected]>; [email protected]; linux- > [email protected] > Subject: Re: [PATCH 2/2] Use bit-wise majority to recover the contents of ONFI > parameter > > On Wed, 2 May 2018 12:25:45 +0200 > Boris Brezillon <[email protected]> wrote: > > > Hi Jane, > > > > On Thu, 26 Apr 2018 17:19:56 -0700 > > Jane Wan <[email protected]> wrote: > > > > > Signed-off-by: Jane Wan <[email protected]> > > > --- > > > drivers/mtd/nand/nand_base.c | 35 +++++++++++++++++++++++++++++++- > --- > > > 1 file changed, 31 insertions(+), 4 deletions(-) > > > > > > diff --git a/drivers/mtd/nand/nand_base.c > > > b/drivers/mtd/nand/nand_base.c index c2e1232..161b523 100644 > > > --- a/drivers/mtd/nand/nand_base.c > > > +++ b/drivers/mtd/nand/nand_base.c > > > @@ -3153,8 +3153,10 @@ static int nand_flash_detect_onfi(struct > mtd_info *mtd, struct nand_chip *chip, > > > int *busw) > > > { > > > struct nand_onfi_params *p = &chip->onfi_params; > > > - int i, j; > > > - int val; > > > + int i, j, k, len, val; > > > + uint8_t copy[3][256], v8; > > > + > > > + len = (sizeof(*p) > 256) ? 256 : sizeof(*p); > > > > > > /* Try ONFI for unknown chip or LP */ > > > chip->cmdfunc(mtd, NAND_CMD_READID, 0x20, -1); @@ -3170,11 > > > +3172,36 @@ static int nand_flash_detect_onfi(struct mtd_info *mtd, struct > nand_chip *chip, > > > le16_to_cpu(p->crc)) { > > > break; > > > } > > > + pr_err("CRC of parameter page %d is not valid\n", i); > > > + for (j = 0; j < len; j++) > > > + copy[i][j] = ((uint8_t *)p)[j]; > > > } > > > > > > if (i == 3) { > > > - pr_err("Could not find valid ONFI parameter page; aborting\n"); > > > - return 0; > > > + pr_err("Could not find valid ONFI parameter page\n"); > > > + pr_info("Recover ONFI parameters with bit-wise majority\n"); > > > + for (j = 0; j < len; j++) { > > > + if (copy[0][j] == copy[1][j] || > > > + copy[0][j] == copy[2][j]) { > > > + ((uint8_t *)p)[j] = copy[0][j]; > > > + } else if (copy[1][j] == copy[2][j]) { > > > + ((uint8_t *)p)[j] = copy[1][j]; > > > + } else { > > > + ((uint8_t *)p)[j] = 0; > > > + for (k = 0; k < 8; k++) { > > > + v8 = (copy[0][j] >> k) & 0x1; > > > + v8 += (copy[1][j] >> k) & 0x1; > > > + v8 += (copy[2][j] >> k) & 0x1; > > > + if (v8 > 1) > > > + ((uint8_t *)p)[j] |= (1 << k); > > > + } > > > + } > > > + } > > > > I'd like this bit-wise majority algorithm to be generic and moved to > > nand_base.c, because we might want to do the same in the core and make > > it work for any number of repetitions of the PARAM page. > > Never mind, I thought you were implementing that in the FSL IFC driver, but > you're actually modifying the core.
0002-mtd-rawnand-fsl_ifc-use-bit-wise-majority-to-recover.patch
Description: 0002-mtd-rawnand-fsl_ifc-use-bit-wise-majority-to-recover.patch
