From: Andy Shevchenko andriy.shevchenko@linux.intel.com
commit 35f3f8504c3b60a1ae5576e178b27fc0ddd6157d upstream.
While fixing undefined behaviour the commit f60d7270c8a3 ("spi: Avoid undefined behaviour when counting unused native CSs") missed the case when all CSs are GPIOs and thus unused_native_cs will be evaluated to -1 in unsigned representation. This will falsely trigger a condition in the spi_get_gpio_descs().
Switch to signed types for *_native_cs SPI controller fields to fix above.
Fixes: f60d7270c8a3 ("spi: Avoid undefined behaviour when counting unused native CSs") Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Link: https://lore.kernel.org/r/20210510131242.49455-1-andriy.shevchenko@linux.int... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Nobuhiro Iwamatsu (CIP) nobuhiro1.iwamatsu@toshiba.co.jp Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/spi/spi.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -646,8 +646,8 @@ struct spi_controller { int *cs_gpios; struct gpio_desc **cs_gpiods; bool use_gpio_descriptors; - u8 unused_native_cs; - u8 max_native_cs; + s8 unused_native_cs; + s8 max_native_cs;
/* statistics */ struct spi_statistics statistics;