Messages in this thread | | | From | "Wan, Jane (Nokia - US/Sunnyvale)" <> | Subject | RE: [PATCH v6] mtd: rawnand: use bit-wise majority to recover the contents of ONFI parameter | Date | Sun, 13 May 2018 04:39:42 +0000 |
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Hi Boris,
I've sent v7 of the patch.
Thanks. Jane
> -----Original Message----- > From: Boris Brezillon [mailto:boris.brezillon@bootlin.com] > Sent: Saturday, May 12, 2018 1:21 AM > To: Wan, Jane (Nokia - US/Sunnyvale) <jane.wan@nokia.com> > Cc: miquel.raynal@bootlin.com; dwmw2@infradead.org; > computersforpeace@gmail.com; richard@nod.at; marek.vasut@gmail.com; > yamada.masahiro@socionext.com; prabhakar.kushwaha@nxp.com; > shawnguo@kernel.org; jagdish.gediya@nxp.com; > shreeya.patel23498@gmail.com; linux-mtd@lists.infradead.org; linux- > kernel@vger.kernel.org; Bos, Ties (Nokia - US/Sunnyvale) <ties.bos@nokia.com> > Subject: Re: [PATCH v6] mtd: rawnand: use bit-wise majority to recover the > contents of ONFI parameter > > On Thu, 10 May 2018 14:28:37 -0700 > Jane Wan <Jane.Wan@nokia.com> 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 <Jane.Wan@nokia.com> > > --- > > v6: support the cases that srcbufs are not contiguous > > v5: make the bit-wise majority functon generic > > v4: move the bit-wise majority code in a separate function > > v3: fix warning message detected by kbuild test robot > > v2: rebase the changes on top of v4.17-rc1 > > > > drivers/mtd/nand/raw/nand_base.c | 52 > ++++++++++++++++++++++++++++++++++---- > > 1 file changed, 47 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/mtd/nand/raw/nand_base.c > > b/drivers/mtd/nand/raw/nand_base.c > > index 72f3a89..acf905c 100644 > > --- a/drivers/mtd/nand/raw/nand_base.c > > +++ b/drivers/mtd/nand/raw/nand_base.c > > @@ -5087,6 +5087,35 @@ static int > > nand_flash_detect_ext_param_page(struct nand_chip *chip, } > > > > /* > > + * 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 cnt, val; > > + > > + val = 0; > > + for (j = 0; j < 8; j++) { > > + 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. > > */ > > static int nand_flash_detect_onfi(struct nand_chip *chip) @@ -5102,7 > > +5131,7 @@ 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; > > > > @@ -5113,21 +5142,34 @@ 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"); > > - goto free_onfi_param_page; > > + const void *srcbufs[3] = {p, p + 1, p + 2}; > > + > > + pr_err("Could not find valid ONFI parameter page\n"); > > Maybe pr_warn() here > > > + pr_info("Recover ONFI params with bit-wise majority\n"); > > and maybe you can pack the 2 messages: > > pr_warn("Could not find a valid ONFI parameter page, trying > bit-wise majority to recover it");
[Jane] Changed as suggested.
> > > + > > + 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 */
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