Messages in this thread | | | Date | Tue, 22 May 2018 12:02:31 +0200 | From | Miquel Raynal <> | Subject | Re: [PATCH v2 09/14] mtd: rawnand: qcom: modify write_oob to remove read codeword part |
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Hi Abhishek,
Some nitpicking below.
On Thu, 3 May 2018 17:50:36 +0530, Abhishek Sahu <absahu@codeaurora.org> wrote:
> QCOM NAND layout protect available OOB data bytes with ECC also so
^controller
> when ecc->write_oob (qcom_nandc_write_oob) is being called then it
You can just state "->write_oob()"
> can't update just OOB bytes. Currently, it first reads the last > codeword which includes old OOB bytes. Then it updates the old OOB > bytes with new one and then again writes the codeword back.
ones?
> The reading codeword is unnecessary since all the other bytes > should be 0xff only.
since the user is responsible to have these bytes cleared to 0xFF.
> > This patch removes the read part and updates the oob bytes with
s/oob/OOB/
> all other data bytes as 0xff.
The end of the sentence is not clear for me. Do you mean that padding with 0xFF is realized before write?
> > Signed-off-by: Abhishek Sahu <absahu@codeaurora.org> > --- > * Changes from v1: > > NEW CHANGE > > drivers/mtd/nand/raw/qcom_nandc.c | 17 +++++------------ > 1 file changed, 5 insertions(+), 12 deletions(-) > > diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c > index 61d0e7d..f85d8ab 100644 > --- a/drivers/mtd/nand/raw/qcom_nandc.c > +++ b/drivers/mtd/nand/raw/qcom_nandc.c > @@ -2067,10 +2067,9 @@ static int qcom_nandc_write_page_raw(struct mtd_info *mtd, > * implements ecc->write_oob() > * > * the NAND controller cannot write only data or only oob within a codeword,
s/oob/OOB/
Remove the trailing ','
> - * since ecc is calculated for the combined codeword. we first copy the > - * entire contents for the last codeword(data + oob), replace the old oob > - * with the new one in chip->oob_poi, and then write the entire codeword. > - * this read-copy-write operation results in a slight performance loss. > + * since ecc is calculated for the combined codeword. So make all the data
s/ecc/ECC/
> + * bytes as 0xff and update the oob from chip->oob_poi, and then write > + * the entire codeword again.
What about "Pad the data area with OxFF before writing."?
> */ > static int qcom_nandc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, > int page) > @@ -2082,20 +2081,14 @@ static int qcom_nandc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, > int data_size, oob_size; > int ret; > > - host->use_ecc = true; > - > - clear_bam_transaction(nandc); > - ret = copy_last_cw(host, page); > - if (ret) > - return ret; > - > - clear_read_regs(nandc); > clear_bam_transaction(nandc); > > /* calculate the data and oob size for the last codeword/step */ > data_size = ecc->size - ((ecc->steps - 1) << 2); > oob_size = mtd->oobavail; > + host->use_ecc = true;
You don't need to move this line here, do you?
> > + memset(nandc->data_buffer, 0xff, host->cw_data); > /* override new oob content to last codeword */ > mtd_ooblayout_get_databytes(mtd, nandc->data_buffer + data_size, oob, > 0, mtd->oobavail);
Once fixed, you can add my:
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Thanks, Miquèl
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