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Date:   Wed, 24 Aug 2022 12:38:46 -0700
From:   Nathan Chancellor <nathan@kernel.org>
To:     Ping-Ke Shih <pkshih@realtek.com>
Cc:     tony0620emma@gmail.com, kvalo@kernel.org,
        linux-wireless@vger.kernel.org
Subject: Re: [PATCH] wifi: rtw88: fix uninitialized use of primary channel
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Message-ID: <YwZ+RsHL+n02gHZx@dev-arch.thelio-3990X>
References: <20220815062004.22920-1-pkshih@realtek.com>
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On Mon, Aug 15, 2022 at 02:20:04PM +0800, Ping-Ke Shih wrote:
> clang reports uninitialized use:
> 
> >> drivers/net/wireless/realtek/rtw88/main.c:731:2: warning: variable
>    'primary_channel_idx' is used uninitialized whenever switch default is
>    taken [-Wsometimes-uninitialized]
>            default:
>            ^~~~~~~
>    drivers/net/wireless/realtek/rtw88/main.c:754:39: note: uninitialized
>    use occurs here
>            hal->current_primary_channel_index = primary_channel_idx;
>                                                 ^~~~~~~~~~~~~~~~~~~
>    drivers/net/wireless/realtek/rtw88/main.c:687:24: note: initialize the
>    variable 'primary_channel_idx' to silence this warning
>            u8 primary_channel_idx;
>                                  ^
>                                   = '\0'
> 
> This situation could not happen, because possible channel bandwidth
> 20/40/80MHz are enumerated.
> 
> Fixes: 341dd1f7de4c ("wifi: rtw88: add the update channel flow to support setting by parameters")
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

Can we get this into -next soon? This warning is breaking our builds due
to CONFIG_WERROR.

> ---
>  drivers/net/wireless/realtek/rtw88/main.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
> index 790dcfed1125d..5a74dda977563 100644
> --- a/drivers/net/wireless/realtek/rtw88/main.c
> +++ b/drivers/net/wireless/realtek/rtw88/main.c
> @@ -697,6 +697,7 @@ void rtw_update_channel(struct rtw_dev *rtwdev, u8 center_channel,
>  
>  	switch (bandwidth) {
>  	case RTW_CHANNEL_WIDTH_20:
> +	default:
>  		primary_channel_idx = RTW_SC_DONT_CARE;
>  		break;
>  	case RTW_CHANNEL_WIDTH_40:
> @@ -728,8 +729,6 @@ void rtw_update_channel(struct rtw_dev *rtwdev, u8 center_channel,
>  			cch_by_bw[RTW_CHANNEL_WIDTH_40] = center_channel - 4;
>  		}
>  		break;
> -	default:
> -		break;
>  	}
>  
>  	switch (center_channel) {
> -- 
> 2.25.1
> 
>