]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
mtd: spi-nor: core: replace dummy buswidth from addr to data
authorCheng Ming Lin <chengminglin@mxic.com.tw>
Tue, 12 Nov 2024 07:52:42 +0000 (15:52 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 14 Dec 2024 18:51:15 +0000 (19:51 +0100)
commite6e42c57cee9fd51039e472146adf133e1093c90
tree27593207cdba5d6a6d35c3e534662a18d36ffff6
parent6827966f6953d9c11d2ac1b96154c57e05f01043
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 <pratyush@kernel.org>
Signed-off-by: Cheng Ming Lin <chengminglin@mxic.com.tw>
Link: https://lore.kernel.org/r/20241112075242.174010-2-linchengming884@gmail.com
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/mtd/spi-nor/core.c