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- From 25f815f66a141436df8a4c45e5d2765272aea2ac Mon Sep 17 00:00:00 2001
- From: Boris Brezillon <[email protected]>
- 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 <[email protected]>
- [[email protected]: tested, fixed and rebased on nand/next]
- Signed-off-by: Miquel Raynal <[email protected]>
- Acked-by: Masahiro Yamada <[email protected]>
- ---
- 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
- @@ -1725,6 +1725,7 @@ 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;
-
- @@ -1750,6 +1751,7 @@ 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;
-
- @@ -1850,6 +1852,8 @@ 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);
-
- @@ -1902,6 +1906,9 @@ static int qcom_nandc_write_page(struct
-
- free_descs(nandc);
-
- + if (!ret)
- + ret = nand_prog_page_end_op(chip);
- +
- return ret;
- }
-
- @@ -1916,6 +1923,7 @@ 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);
-
- @@ -1970,6 +1978,9 @@ static int qcom_nandc_write_page_raw(str
-
- free_descs(nandc);
-
- + if (!ret)
- + ret = nand_prog_page_end_op(chip);
- +
- return ret;
- }
-
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