Re: [PATCH] staging: rtl8723bs: core: rtw_mlme_ext.c: move the declaration and initialization of 'evt_seq' inside ifdef macro

[Fabio Aiuto]

Hi Yu,

On Sat, May 29, 2021 at 05:29:48PM +0800, Yu Kuai wrote:
> 'evt_seq' is only used if 'CHECK_ENENT_SEQ' is defined, however,
> it's declared and initialized even if 'CHECK_ENENT_SEQ' is not
> defined. Thus gcc will report following warning if
> 'CHECK_ENENT_SEQ' is not defined:

the macro is mispelled in the commit description

> 
> drivers/staging/rtl8723bs/core/rtw_mlme_ext.c:6009:15: warning:
>  variable ‘evt_seq’ set but not used [-Wunused-but-set-variable]
>  6009 |  u8 evt_code, evt_seq;
> 
> Thus move the declaration and initialization of 'evt_seq' inside
> ifdef macro to fix it.
> 
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> ---
>  drivers/staging/rtl8723bs/core/rtw_mlme_ext.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c b/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c
> index 97b3c2965770..e883371cc96d 100644
> --- a/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c
> +++ b/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c
> @@ -6006,7 +6006,10 @@ static struct fwevent wlanevents[] = {
>  
>  u8 mlme_evt_hdl(struct adapter *padapter, unsigned char *pbuf)
>  {
> -	u8 evt_code, evt_seq;
> +#ifdef CHECK_EVENT_SEQ
> +	u8 evt_seq;
> +#endif
> +	u8 evt_code;
>  	u16 evt_sz;
>  	uint	*peventbuf;
>  	void (*event_callback)(struct adapter *dev, u8 *pbuf);
> @@ -6017,18 +6020,17 @@ u8 mlme_evt_hdl(struct adapter *padapter, unsigned char *pbuf)
>  
>  	peventbuf = (uint *)pbuf;
>  	evt_sz = (u16)(*peventbuf&0xffff);
> -	evt_seq = (u8)((*peventbuf>>24)&0x7f);
>  	evt_code = (u8)((*peventbuf>>16)&0xff);
>  
> -
> -	#ifdef CHECK_EVENT_SEQ
> +#ifdef CHECK_EVENT_SEQ
>  	/*  checking event sequence... */
> +	evt_seq = (u8)((*peventbuf>>24)&0x7f);
>  	if (evt_seq != (atomic_read(&pevt_priv->event_seq) & 0x7f)) {
>  		pevt_priv->event_seq = (evt_seq+1)&0x7f;
>  
>  		goto _abort_event_;
>  	}
> -	#endif
> +#endif
>  
>  	/*  checking if event code is valid */
>  	if (evt_code >= MAX_C2HEVT)
> -- 
> 2.25.4
> 
> 

this conditional block seems to be dead code, for
the symbolic constant CHECK_EVENT_SEQ is defined nowhere in
the code.

/staging$ grep -r CHECK_EVENT_SEQ .
./staging/rtl8723bs/core/rtw_mlme_ext.c:	#ifdef CHECK_EVENT_SEQ

so the variable can be safely removed together with
the dead code block.

thank you,

fabio