[PATCH] mtd: spi-nor: honour max_data_size for spi-nor writes

From: Yogesh Gaur
Date: Mon Jun 11 2018 - 05:20:02 EST


Honour max_data_size for spi-nor writes
In new spi-mem framework, data size to be written is being calculated
using spi_mem_adjust_op_size().
This can return value less than nor->page_size.

Add check value of data size return from API spi_mem_adjust_op_size()
with the actual requested data size and write, max, only supported
data size.

Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur@xxxxxxx>
---
drivers/mtd/devices/m25p80.c | 23 ++++++++---------------
drivers/mtd/spi-nor/spi-nor.c | 7 -------
2 files changed, 8 insertions(+), 22 deletions(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index e84563d..60224fe 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -72,7 +72,6 @@ static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
SPI_MEM_OP_ADDR(nor->addr_width, to, 1),
SPI_MEM_OP_DUMMY(0, 1),
SPI_MEM_OP_DATA_OUT(len, buf, 1));
- size_t remaining = len;
int ret;

/* get transfer protocols. */
@@ -84,22 +83,16 @@ static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
op.addr.nbytes = 0;

- while (remaining) {
- op.data.nbytes = remaining < UINT_MAX ? remaining : UINT_MAX;
- ret = spi_mem_adjust_op_size(flash->spimem, &op);
- if (ret)
- return ret;
-
- ret = spi_mem_exec_op(flash->spimem, &op);
- if (ret)
- return ret;
+ ret = spi_mem_adjust_op_size(flash->spimem, &op);
+ if (ret)
+ return ret;
+ op.data.nbytes = len < op.data.nbytes ? len : op.data.nbytes;

- op.addr.val += op.data.nbytes;
- remaining -= op.data.nbytes;
- op.data.buf.out += op.data.nbytes;
- }
+ ret = spi_mem_exec_op(flash->spimem, &op);
+ if (ret)
+ return ret;

- return len;
+ return op.data.nbytes;
}

/*
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 5bfa36e..3e63543 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -1431,13 +1431,6 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
goto write_err;
*retlen += written;
i += written;
- if (written != page_remain) {
- dev_err(nor->dev,
- "While writing %zu bytes written %zd bytes\n",
- page_remain, written);
- ret = -EIO;
- goto write_err;
- }
}

write_err:
--
2.7.4

Patch is based on the spi-mem framework[1]
[1]https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git/log/?h=for-4.18