From 77f53f49ad628429cf0664d3df3ee7df41b4a7d8 Mon Sep 17 00:00:00 2001 From: Cheng Ming Lin Date: Tue, 12 Nov 2024 15:52:42 +0800 Subject: mtd: spi-nor: core: replace dummy buswidth from addr to data commit 98d1fb94ce75f39febd456d6d3cbbe58b6678795 upstream. The default dummy cycle for Macronix SPI NOR flash in Octal Output Read Mode(1-1-8) is 20. Currently, the dummy buswidth is set according to the address bus width. In the 1-1-8 mode, this means the dummy buswidth is 1. When converting dummy cycles to bytes, this results in 20 x 1 / 8 = 2 bytes, causing the host to read data 4 cycles too early. Since the protocol data buswidth is always greater than or equal to the address buswidth. Setting the dummy buswidth to match the data buswidth increases the likelihood that the dummy cycle-to-byte conversion will be divisible, preventing the host from reading data prematurely. Fixes: 0e30f47232ab ("mtd: spi-nor: add support for DTR protocol") Cc: stable@vger.kernel.org Reviewed-by: Pratyush Yadav Signed-off-by: Cheng Ming Lin Link: https://lore.kernel.org/r/20241112075242.174010-2-linchengming884@gmail.com Signed-off-by: Tudor Ambarus Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/spi-nor/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 9d6e85bf227b..8c57df44c40f 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -89,7 +89,7 @@ void spi_nor_spimem_setup_op(const struct spi_nor *nor, op->addr.buswidth = spi_nor_get_protocol_addr_nbits(proto); if (op->dummy.nbytes) - op->dummy.buswidth = spi_nor_get_protocol_addr_nbits(proto); + op->dummy.buswidth = spi_nor_get_protocol_data_nbits(proto); if (op->data.nbytes) op->data.buswidth = spi_nor_get_protocol_data_nbits(proto); -- cgit v1.2.3