[PATCH 6.19 253/781] spi: microchip-core: use XOR instead of ANDNOT to fix the logic

Greg Kroah-Hartman
2026-02-25T01:31:39Z

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

[ Upstream commit 19a4505a7a5d4eea70f1a42d601c25d730922fdf ]

Use XOR instead of ANDNOT to fix the logic. The current approach with
(foo & BAR & ~baz) is harder to process, and it proved to be wrong,
than more usual pattern for the comparing misconfiguration using
((foo ^ baz) & BAR) which can be read as "find all different bits
between foo and baz that are related to BAR (mask)". Besides that
it makes the binary code shorter.

Function old new delta
mchp_corespi_setup 103 99 -4

Fixes: 059f545832be ("spi: add support for microchip "soft" spi controller")
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Prajna Rajendra Kumar <prajna.rajendrakumar@microchip.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260108175100.3535306-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-microchip-core-spi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-microchip-core-spi.c b/drivers/spi/spi-microchip-core-spi.c
index 89e40fc45d73a..c8ebb58e0369a 100644
--- a/drivers/spi/spi-microchip-core-spi.c
+++ b/drivers/spi/spi-microchip-core-spi.c
@@ -161,7 +161,7 @@ static int mchp_corespi_setup(struct spi_device *spi)
return -EOPNOTSUPP;
}

- if (spi->mode & SPI_MODE_X_MASK & ~spi->controller->mode_bits) {
+ if ((spi->mode ^ spi->controller->mode_bits) & SPI_MODE_X_MASK) {
dev_err(&spi->dev, "incompatible CPOL/CPHA, must match controller's Motorola mode\n");
return -EINVAL;
}
--
2.51.0