Re: [PATCH 09/17] soundwire: stream: remove unnecessary variable initializations

Pierre-Louis Bossart
2019-08-06T15:39:28Z

On 8/6/19 10:31 AM, Cezary Rojewski wrote:
> On 2019-08-06 02:55, Pierre-Louis Bossart wrote:
>> @@ -1493,6 +1493,11 @@ static int _sdw_prepare_stream(struct
>> sdw_stream_runtime *stream)
>>           }
>>       }
>> +    if (!bus) {
>> +        pr_err("Configuration error in %s\n", __func__);
>> +        return -EINVAL;
>> +    }
>> +
>
> This should probably be located in separate path - not at all an
> initialization removal.

It's a consequence of the initialization removal: because we are
removing the default init, there is a risk that the loop just before do
not set it, so it's required to trap the case where the variable in not
initialized.

>
>> @@ -1573,6 +1578,11 @@ static int _sdw_enable_stream(struct
>> sdw_stream_runtime *stream)
>>           }
>>       }
>> +    if (!bus) {
>> +        pr_err("Configuration error in %s\n", __func__);
>> +        return -EINVAL;
>> +    }
>> +
>
> Same here.

same reply

>
>> @@ -1639,13 +1650,14 @@ static int _sdw_disable_stream(struct
>> sdw_stream_runtime *stream)
>>       ret = do_bank_switch(stream);
>>       if (ret < 0) {
>> -        dev_err(bus->dev, "Bank switch failed: %d\n", ret);
>> +        pr_err("Bank switch failed: %d\n", ret);
>>           return ret;
>>       }
>
> Here too.

no, same thing, the bus variable is initialized in loops so tools will
report a possible path where bus->dev is an invalid dereference.

> I might have missed something though I bet you got my point.