Messages in this thread | | | Date | Tue, 22 May 2018 19:44:54 +0530 | From | Abhishek Sahu <> | Subject | Re: [PATCH v2 09/14] mtd: rawnand: qcom: modify write_oob to remove read codeword part |
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On 2018-05-22 15:32, Miquel Raynal wrote: > 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:
Thanks Miquel. I will fix all these and update the patch.
Regards, Abhishek
> > Acked-by: Miquel Raynal <miquel.raynal@bootlin.com> > > Thanks, > Miquèl
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