Re: [PATCH v3 16/17] spi: s3c64xx: drop a superfluous bitwise NOT operation

From: Sam Protsenko
Date: Fri Jan 26 2024 - 15:09:57 EST


On Fri, Jan 26, 2024 at 11:16 AM Tudor Ambarus <tudor.ambarus@xxxxxxxxxx> wrote:
>
> val &= ~mask;
> val |= mask;
>
> is equivalent to:
> val |= mask;
>
> Drop the superfluous bitwise NOT operation.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>
> ---

That's much more clear. Also I'm pretty sure if you compare .o file
before and after the patch, they would be identical -- another way to
argue the patch has no functional change.

Reviewed-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx>

> drivers/spi/spi-s3c64xx.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
> index e9344fe71e56..43b888c8812e 100644
> --- a/drivers/spi/spi-s3c64xx.c
> +++ b/drivers/spi/spi-s3c64xx.c
> @@ -1089,7 +1089,6 @@ static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd)
>
> val = readl(regs + S3C64XX_SPI_MODE_CFG);
> val &= ~S3C64XX_SPI_MODE_4BURST;
> - val &= ~(S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
> val |= (S3C64XX_SPI_MAX_TRAILCNT << S3C64XX_SPI_TRAILCNT_OFF);
> writel(val, regs + S3C64XX_SPI_MODE_CFG);
>
> --
> 2.43.0.429.g432eaa2c6b-goog
>