Re: [PATCH] staging: sm750fb: fix unused tmp in sw_i2c_wait

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Jan 05, 2026 at 10:10:26AM +0800, Sun Jian wrote:
> clang W=1 warns that 'tmp' is set but not used in sw_i2c_wait().
> 
> Replace the dummy loop with cpu_relax() to keep the delay loop without
> triggering -Wunused-but-set-variable.
> 
> No functional change intended.
> 
> Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
> ---
>  drivers/staging/sm750fb/ddk750_swi2c.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/staging/sm750fb/ddk750_swi2c.c b/drivers/staging/sm750fb/ddk750_swi2c.c
> index 0ef8d4ff2ef9..279a1a10f132 100644
> --- a/drivers/staging/sm750fb/ddk750_swi2c.c
> +++ b/drivers/staging/sm750fb/ddk750_swi2c.c
> @@ -92,12 +92,11 @@ static void sw_i2c_wait(void)
>       * it's more reliable than counter loop ..
>       * write 0x61 to 0x3ce and read from 0x3cf
>       */
> -	int i, tmp;
> +	int i;
> +
> +	for (i = 0; i < 600; i++)
> +		cpu_relax();
>  
> -	for (i = 0; i < 600; i++) {
> -		tmp = i;
> -		tmp += i;
> -	}

You just slowed down this loop a lot, are you sure it still works?  And
really, either way, this isn't the proper way to "sleep", as it will
be different speeds on different cpus/systems, and not work properly at
all.  Can you fix this correctly?

thanks,

greg k-h