Messages in this thread |  | | Date | Sat, 28 Apr 2018 14:06:38 +0200 | From | Miquel Raynal <> | Subject | Re: [PATCH 2/2] Use bit-wise majority to recover the contents of ONFI parameter |
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Hi Jane,
Same comments as before, please: get the right maintainers, add a commit log, rebase and fix the title prefix.
Have you ever needed/tried this algorithm before?
On Thu, 26 Apr 2018 17:19:56 -0700, Jane Wan <Jane.Wan@nokia.com> wrote:
> Signed-off-by: Jane Wan <Jane.Wan@nokia.com> > --- > 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;
Please use u8 instead of uint8_t (./scripts/checkpatch.pl --strict will give you the list of styling issues to fix.
I don't think you should allocate that much space on the stack, please use dynamic allocation.
> + > + len = (sizeof(*p) > 256) ? 256 : sizeof(*p);
This is a maximum derivation, there are helpers for that.
I am not sure this is relevant, won't you read only 256 bytes anyway?
> > /* 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; > }
Space.
> + 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];
'copy' is maybe not a meaningful name.
> } > > 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 could be declared in the else statement of in the for loop. The name could also be changed.
> + v8 += (copy[1][j] >> k) & 0x1; > + v8 += (copy[2][j] >> k) & 0x1; > + if (v8 > 1) > + ((uint8_t *)p)[j] |= (1 << k);
Please use the BIT() macro.
> + } > + } > + }
Space.
> + if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) != > + le16_to_cpu(p->crc)) { > + pr_err("ONFI parameter recovery failed, aborting\n"); > + return 0; > + } > } > > /* Check version */
Thanks, Miquèl
-- Miquel Raynal, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com
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