Re: [PATCH v2 2/2] spi: realtek-rtl: Improve readability when clearing the size mask

[Sander Vanheule <sander@svanheule.net>]

On Thu, 2022-07-28 at 17:21 +0200, Martin Blumenstingl wrote:
> Define the bitmask RTL_SPI_SFCSR_LEN_MASK so it only sets the bits of
> this specific part of the register instead of setting all bits except
> the relevant ones. This makes it consistent with single bit macros in
> the spi-realtek-rtl driver as well as with the approach that many other
> drivers use.
> 
> Suggested-by: Sander Vanheule <sander@svanheule.net>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

FWIW
Tested-by: Sander Vanheule <sander@svanheule.net>

on my Netgear GS110TPP v1.

> ---
>  drivers/spi/spi-realtek-rtl.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/spi/spi-realtek-rtl.c b/drivers/spi/spi-realtek-rtl.c
> index 866b0477dbd7..0371d44cbfbd 100644
> --- a/drivers/spi/spi-realtek-rtl.c
> +++ b/drivers/spi/spi-realtek-rtl.c
> @@ -20,7 +20,7 @@ struct rtspi {
>  #define RTL_SPI_SFCSR_CSB1             BIT(30)
>  #define RTL_SPI_SFCSR_RDY              BIT(27)
>  #define RTL_SPI_SFCSR_CS               BIT(24)
> -#define RTL_SPI_SFCSR_LEN_MASK         ~(0x03 << 28)
> +#define RTL_SPI_SFCSR_LEN_MASK         (0x03 << 28)
>  #define RTL_SPI_SFCSR_LEN1             (0x00 << 28)
>  #define RTL_SPI_SFCSR_LEN4             (0x03 << 28)
>  
> @@ -49,7 +49,7 @@ static void set_size(struct rtspi *rtspi, int size)
>         u32 value;
>  
>         value = readl(REG(RTL_SPI_SFCSR));
> -       value &= RTL_SPI_SFCSR_LEN_MASK;
> +       value &= ~RTL_SPI_SFCSR_LEN_MASK;
>         if (size == 4)
>                 value |= RTL_SPI_SFCSR_LEN4;
>         else if (size == 1)