Re: [PATCH] spi: cadence-quadspi: Silence shiftTooManyBitsSigned warning

[Dan Carpenter <dan.carpenter@xxxxxxxxxx>]

On Thu, Mar 04, 2021 at 06:47:52PM +0800, Jay Fang wrote:
> drivers/spi/spi-cadence-quadspi.c:267:18: warning: Shifting signed 32-bit
> value by 31 bits is undefined behaviour [shiftTooManyBitsSigned]
>     return reg & (1 << CQSPI_REG_CONFIG_IDLE_LSB);
>                     ^
> 
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Signed-off-by: Jay Fang <f.fangjian@xxxxxxxxxx>
> ---
>  drivers/spi/spi-cadence-quadspi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
> index 442cc7c..9a2798a5 100644
> --- a/drivers/spi/spi-cadence-quadspi.c
> +++ b/drivers/spi/spi-cadence-quadspi.c
> @@ -264,7 +264,7 @@ static bool cqspi_is_idle(struct cqspi_st *cqspi)
>  {
>  	u32 reg = readl(cqspi->iobase + CQSPI_REG_CONFIG);
>  
> -	return reg & (1 << CQSPI_REG_CONFIG_IDLE_LSB);
> +	return reg & (1UL << CQSPI_REG_CONFIG_IDLE_LSB);

This is always going to be false because reg is a u32.

regards,
dan carpenter