5.15-stable review patch. If anyone has any objections, please let me know.
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From: Cheng Ming Lin chengminglin@mxic.com.tw
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 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- 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 struc 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);