]> 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>
Thu, 5 Dec 2024 12:54:17 +0000 (13:54 +0100)
commit487db736d7c3bdd8726a9b6fe1aa0c5f8c2ba8a4
treea1ca859cf5cbe24d3d9e1828b321d8b619fac845
parent5a0e8a1c2be539716cbaeb211f949e54310a6109
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