From 28eed9f6cab6ab28cdca4a43df4f8ed51dd5f8f8 Mon Sep 17 00:00:00 2001 From: Abhishek Sahu Date: Wed, 20 Jun 2018 12:57:37 +0530 Subject: [PATCH] mtd: rawnand: qcom: modify write_oob to remove read codeword part QCOM NAND controller layout protects available OOB data bytes with ECC also so when ecc->write_oob() is being called then it 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 ones and then again writes the codeword back. The reading codeword is unnecessary since user is responsible to have these bytes cleared to 0xFF. This patch removes the read part and updates the OOB bytes with data area padded with OxFF. Signed-off-by: Abhishek Sahu Signed-off-by: Miquel Raynal --- drivers/mtd/nand/raw/qcom_nandc.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c index 285b2ad3..28361b5 100644 --- a/drivers/mtd/nand/raw/qcom_nandc.c +++ b/drivers/mtd/nand/raw/qcom_nandc.c @@ -2064,11 +2064,9 @@ 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, - * 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. + * the NAND controller cannot write only data or only OOB within a codeword + * since ECC is calculated for the combined codeword. So update the OOB from + * chip->oob_poi, and pad the data area with OxFF before writing. */ static int qcom_nandc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, int page) @@ -2081,19 +2079,13 @@ static int qcom_nandc_write_oob(struct mtd_info *mtd, struct nand_chip *chip, 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; + 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); -- 2.7.4