lkml.org 
[lkml]   [2018]   [May]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH v3 2/2] mtd: rawnand: fsl_ifc: use bit-wise majority to recover the contents of ONFI parameter
Date
Hi Boris,

I've sent v4 of the patches based on the comments.

Thanks.
Jane

> -----Original Message-----
> From: Boris Brezillon [mailto:boris.brezillon@bootlin.com]
> Sent: Tuesday, May 08, 2018 2:09 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 v3 2/2] mtd: rawnand: fsl_ifc: use bit-wise majority to
> recover the contents of ONFI parameter
>
> On Mon, 7 May 2018 09:34:15 -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>
>
> 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.

[Jane] Thanks for the info. I've sent both patches on v4.

>
> > ---
> > 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.

[Jane] Removed buf in v4.

>
> > + 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?

[Jane] Done as suggested in v4.

>
> > + 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.

[Jane] Removed the check. Thanks.

>
> > return ret;
> > }
> >

\
 
 \ /
  Last update: 2018-05-08 23:29    [W:0.072 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site