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From 25f815f66a141436df8a4c45e5d2765272aea2ac Mon Sep 17 00:00:00 2001
From: Boris Brezillon <boris.brezillon@free-electrons.com>
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 <boris.brezillon@free-electrons.com>
[miquel.raynal@free-electrons.com: tested, fixed and rebased on nand/next]
Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---
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;
}
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