[PATCH v8 14/28] mtd: spi-nor-core: Do not set data direction when there is no data

Pratyush Yadav p.yadav at ti.com
Thu Apr 1 21:31:19 CEST 2021

Even when spi_nor_write_reg() has no data to write, like when executing
a write enable operation, it sets the data direction to
SPI_MEM_DATA_OUT. This trips up spi_mem_check_buswidth() because it
expects a data phase when there is none. Make sure the data direction is
set to SPI_MEM_NO_DATA when there is no data to write.

Signed-off-by: Pratyush Yadav <p.yadav at ti.com>
 drivers/mtd/spi/spi-nor-core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index b2a25b0099..1816319ad0 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -209,6 +209,9 @@ static int spi_nor_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
 					  SPI_MEM_OP_DATA_OUT(len, NULL, 1));
+	if (len == 0)
+		op.data.dir = SPI_MEM_NO_DATA;
 	return spi_nor_read_write_reg(nor, &op, buf);

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