Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <fc25d296-b245-9a5d-302f-c313f239569e@infradead.org>
Date:   Tue, 11 Jul 2023 14:07:57 -0700
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.12.0
Subject: Re: [PATCH net] wifi: airo: avoid uninitialized warning in
 airo_get_rate()
Content-Language: en-US
To:     Simon Horman <simon.horman@corigine.com>
Cc:     linux-kernel@vger.kernel.org,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Kalle Valo <kvalo@kernel.org>, linux-wireless@vger.kernel.org,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org
References: <20230709133154.26206-1-rdunlap@infradead.org>
 <ZK2QeBZKWi0Q6vuW@corigine.com>
From:   Randy Dunlap <rdunlap@infradead.org>
In-Reply-To: <ZK2QeBZKWi0Q6vuW@corigine.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hi Simon,

On 7/11/23 10:25, Simon Horman wrote:
> On Sun, Jul 09, 2023 at 06:31:54AM -0700, Randy Dunlap wrote:
>> Quieten a gcc (11.3.0) build error or warning by checking the function
>> call status and returning -EBUSY if the function call failed.
>> This is similar to what several other wireless drivers do for the
>> SIOCGIWRATE ioctl call when there is a locking problem.
>>
>> drivers/net/wireless/cisco/airo.c: error: 'status_rid.currentXmitRate' is used uninitialized [-Werror=uninitialized]
> 
> Hi Randy,
> 
> There seem to be other calls to readStatusRid() in the same file
> with similar properties. Perhaps it would be best to fix them too?
> 

Yes, there are 40+ calls that could have problems.
Please see this thread:
  https://lore.kernel.org/all/2f6ffd1c-a756-b7b8-bba4-77c2308f26b9@infradead.org/

This is an attempt to shut up the build error/warning, which only occurs after
this one function call.

For such an old driver/hardware, I don't plan to do massive surgery
to it.

>> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
>> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
>> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
>> Link: lore.kernel.org/r/39abf2c7-24a-f167-91da-ed4c5435d1c4@linux-m68k.org
>> Cc: Kalle Valo <kvalo@kernel.org>
>> Cc: linux-wireless@vger.kernel.org
>> Cc: "David S. Miller" <davem@davemloft.net>
>> Cc: Eric Dumazet <edumazet@google.com>
>> Cc: Jakub Kicinski <kuba@kernel.org>
>> Cc: Paolo Abeni <pabeni@redhat.com>
>> Cc: netdev@vger.kernel.org
>> ---
>>  drivers/net/wireless/cisco/airo.c |    5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff -- a/drivers/net/wireless/cisco/airo.c b/drivers/net/wireless/cisco/airo.c
>> --- a/drivers/net/wireless/cisco/airo.c
>> +++ b/drivers/net/wireless/cisco/airo.c
>> @@ -6157,8 +6157,11 @@ static int airo_get_rate(struct net_devi
>>  	struct iw_param *vwrq = &wrqu->bitrate;
>>  	struct airo_info *local = dev->ml_priv;
>>  	StatusRid status_rid;		/* Card status info */
>> +	int ret;
>>  
>> -	readStatusRid(local, &status_rid, 1);
>> +	ret = readStatusRid(local, &status_rid, 1);
>> +	if (ret)
>> +		return -EBUSY;
>>  
>>  	vwrq->value = le16_to_cpu(status_rid.currentXmitRate) * 500000;
>>  	/* If more than one rate, set auto */
>>

-- 
~Randy