[PATCH] mtd: spi-nor: Fix the number of bytes for the dummy cycles

From: Allen-KH Cheng
Date: Mon Oct 31 2022 - 08:47:08 EST


The number of bytes used by spi_nor_spimem_check_readop() may be
incorrect for the dummy cycles. Since nor->read_dummy is not initialized
before spi_nor_spimem_adjust_hwcaps().

We use both mode and wait state clock cycles instead of nor->read_dummy.

Fixes: 0e30f47232ab ("mtd: spi-nor: add support for DTR protocol")
Co-developed-by: Bayi Cheng <bayi.cheng@xxxxxxxxxxxx>
Signed-off-by: Bayi Cheng <bayi.cheng@xxxxxxxxxxxx>
Signed-off-by: Allen-KH Cheng <allen-kh.cheng@xxxxxxxxxxxx>
---
drivers/mtd/spi-nor/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 6c921eb3fadb..8b9c318a0ad4 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -1914,7 +1914,8 @@ static int spi_nor_spimem_check_readop(struct spi_nor *nor,
spi_nor_spimem_setup_op(nor, &op, read->proto);

/* convert the dummy cycles to the number of bytes */
- op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;
+ op.dummy.nbytes = (read->num_mode_clocks + read->num_wait_states) *
+ op.dummy.buswidth / 8;
if (spi_nor_protocol_is_dtr(nor->read_proto))
op.dummy.nbytes *= 2;

--
2.18.0