[U-Boot] [PATCH v2] mtd: spi: Improve spi_nor_write_data() implementation

[Rajat Srivastava]

Maximum write size in a single write operation in
spi_nor_write_data() function can be equal to slave
tx buffer, which is adjusted in spi_mem_adjust_op_size()
and write operation gets fragmented.

Previously data write for the above fragmentation
didn't incorporate write enable and status checks.
It was sent to flash at page offsets only.

Signed-off-by: Rajat Srivastava <rajat.srivastava at nxp.com>
---
Changes in v2:
 Incorporating review comments given by Vignesh.
 [PATCH v1]: https://patchwork.ozlabs.org/patch/1078183/

 drivers/mtd/spi/spi-nor-core.c | 28 ++++++++++------------------
 1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index c4e2f6a08f..8e754d445d 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -116,7 +116,6 @@ static ssize_t spi_nor_write_data(struct spi_nor *nor, loff_t to, size_t len,
 				   SPI_MEM_OP_ADDR(nor->addr_width, to, 1),
 				   SPI_MEM_OP_NO_DUMMY,
 				   SPI_MEM_OP_DATA_OUT(len, buf, 1));
-	size_t remaining = len;
 	int ret;
 
 	/* get transfer protocols. */
@@ -127,22 +126,19 @@ static ssize_t spi_nor_write_data(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(nor->spi, &op);
-		if (ret)
-			return ret;
+	op.data.nbytes = len < UINT_MAX ? len : UINT_MAX;
+	ret = spi_mem_adjust_op_size(nor->spi, &op);
+	if (ret)
+		return ret;
 
-		ret = spi_mem_exec_op(nor->spi, &op);
-		if (ret)
-			return ret;
+	ret = spi_mem_exec_op(nor->spi, &op);
+	if (ret)
+		return ret;
 
-		op.addr.val += op.data.nbytes;
-		remaining -= op.data.nbytes;
-		op.data.buf.out += op.data.nbytes;
-	}
+	op.addr.val += op.data.nbytes;
+	op.data.buf.out += op.data.nbytes;
 
-	return len;
+	return op.data.nbytes;
 }
 
 /*
@@ -1101,10 +1097,6 @@ 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) {
-			ret = -EIO;
-			goto write_err;
-		}
 	}
 
 write_err:
-- 
2.14.1