Re: [PATCH 27/36] tty: synclinkmp: Mark never checked 'readval' as __always_unused

[Jiri Slaby]

On 04. 11. 20, 20:35, Lee Jones wrote:
> Fixes the following W=1 kernel build warning(s):
>
>   drivers/tty/synclinkmp.c: In function ‘init_adapter’:
>   drivers/tty/synclinkmp.c:5167:6: warning: variable ‘readval’ set but not used [-Wunused-but-set-variable]
>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Jiri Slaby <jirislaby@xxxxxxxxxx>
> Cc: paulkf@xxxxxxxxxxxxx
> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
>   drivers/tty/synclinkmp.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/tty/synclinkmp.c b/drivers/tty/synclinkmp.c
> index 0ca738f61a35b..75f494bfdcbed 100644
> --- a/drivers/tty/synclinkmp.c
> +++ b/drivers/tty/synclinkmp.c
> @@ -5165,7 +5165,7 @@ static bool init_adapter(SLMP_INFO *info)
>   
>   	/* Set BIT30 of Local Control Reg 0x50 to reset SCA */
>   	volatile u32 *MiscCtrl = (u32 *)(info->lcr_base + 0x50);
> -	u32 readval;
> +	u32 __always_unused readval;

Why not just remove readval completely as in other cases?

And the loop can be turned into ndelay:

        /*
         * Force at least 170ns delay before clearing
         * reset bit. Each read from LCR takes at least
         * 30ns so 10 times for 300ns to be safe.
         */
        for(i=0;i<10;i++)
                readval = *MiscCtrl;


thanks,
--
js
suse labs