]> git.hungrycats.org Git - linux/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>
Mon, 9 Dec 2024 09:32:48 +0000 (10:32 +0100)
commit13dc02cae4e32715a72fccb3a38629ea4e5c77fd
tree7fcf58a1962ff5f97981023904a7565bd5446330
parent66f0fbc8ba18d69d707d22b7f766b610a957c23b
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