Hi Abhishek, Some nitpicking below.
On Thu, 3 May 2018 17:50:36 +0530, Abhishek Sahu <[email protected]> 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 <[email protected]> > --- > * 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 <[email protected]> Thanks, Miquèl
