From 25f815f66a141436df8a4c45e5d2765272aea2ac Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Thu, 30 Nov 2017 18:01:30 +0100 Subject: [PATCH 5/7] mtd: nand: force drivers to explicitly send READ/PROG commands The core currently send the READ0 and SEQIN+PAGEPROG commands in nand_do_read/write_ops(). This is inconsistent with ->read/write_oob[_raw]() hooks behavior which are expected to send these commands. There's already a flag (NAND_ECC_CUSTOM_PAGE_ACCESS) to inform the core that a specific controller wants to send the READ/SEQIN+PAGEPROG commands on its own, but it's an opt-in flag, and existing drivers are unlikely to be updated to pass it. Moreover, some controllers cannot dissociate the READ/PAGEPROG commands from the associated data transfer and ECC engine activation, and developers have to hack things in their ->cmdfunc() implementation to handle such complex cases, or have to accept the perf penalty of sending twice the same command. To address this problem we are planning on adding a new interface which is passed all information about a NAND operation (including the amount of data to transfer) and replacing all calls to ->cmdfunc() to calls to this new ->exec_op() hook. But, in order to do that, we need to have all ->cmdfunc() calls placed near their associated ->read/write_buf/byte() calls. Modify the core and relevant drivers to make NAND_ECC_CUSTOM_PAGE_ACCESS the default case, and remove this flag. Signed-off-by: Boris Brezillon [miquel.raynal@free-electrons.com: tested, fixed and rebased on nand/next] Signed-off-by: Miquel Raynal Acked-by: Masahiro Yamada --- drivers/mtd/nand/qcom_nandc.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/mtd/nand/qcom_nandc.c +++ b/drivers/mtd/nand/qcom_nandc.c @@ -1727,6 +1727,7 @@ static int qcom_nandc_read_page(struct m u8 *data_buf, *oob_buf = NULL; int ret; + nand_read_page_op(chip, page, 0, NULL, 0); data_buf = buf; oob_buf = oob_required ? chip->oob_poi : NULL; @@ -1752,6 +1753,7 @@ static int qcom_nandc_read_page_raw(stru int i, ret; int read_loc; + nand_read_page_op(chip, page, 0, NULL, 0); data_buf = buf; oob_buf = chip->oob_poi; @@ -1852,6 +1854,8 @@ static int qcom_nandc_write_page(struct u8 *data_buf, *oob_buf; int i, ret; + nand_prog_page_begin_op(chip, page, 0, NULL, 0); + clear_read_regs(nandc); clear_bam_transaction(nandc); @@ -1904,6 +1908,9 @@ static int qcom_nandc_write_page(struct free_descs(nandc); + if (!ret) + ret = nand_prog_page_end_op(chip); + return ret; } @@ -1918,6 +1925,7 @@ static int qcom_nandc_write_page_raw(str u8 *data_buf, *oob_buf; int i, ret; + nand_prog_page_begin_op(chip, page, 0, NULL, 0); clear_read_regs(nandc); clear_bam_transaction(nandc); @@ -1972,6 +1980,9 @@ static int qcom_nandc_write_page_raw(str free_descs(nandc); + if (!ret) + ret = nand_prog_page_end_op(chip); + return ret; }