From 98d1fb94ce75f39febd456d6d3cbbe58b6678795 Mon Sep 17 00:00:00 2001 From: Cheng Ming Lin Date: Tue, 12 Nov 2024 15:52:42 +0800 Subject: [PATCH] mtd: spi-nor: core: replace dummy buswidth from addr to data 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 --- 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 b6f374ded390a..66949d9f0cc5a 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); -- 2.39.5