Re: [PATCH v7 4/7] can: provide a separate bittiming_const parameter to bittiming functions

[Marc Kleine-Budde <mkl@pengutronix.de>]

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On 02/28/2014 01:31 PM, Oliver Hartkopp wrote:
> 
> 
> On 28.02.2014 11:46, Marc Kleine-Budde wrote:
>> On 02/28/2014 11:26 AM, Oliver Hartkopp wrote:
> 
> 
>>>  {
>>> -	struct can_priv *priv = netdev_priv(dev);
>>> -	int err;
>>> +	int err = -EINVAL;
>>
>> Keep err uninitialized and make an explicit else err = -EINVAL.... see
>> below:
>>
> 
> 
>>> +	if (!bt->tq) {
>>> +		/* non-expert mode: Determine bit-timing parameters */
>>> +		if (bt->bitrate)
>>
>> Why not:
>> 	if (!bt->tq && bt->bitrate) {
>>
>>> +			err = can_calc_bittiming(dev, bt, btc);
>>> +	} else {
>>
>> 	} else if (bt->tq && !bt->bitrate) {
>>
>>> +		/*
>>> +		 * expert mode: Check bit-timing parameters and
>>> +		 * calculate proper brp and a human readable bitrate
>>> +		 */
>>> +		if (!bt->bitrate)
>>> +			err = can_fixup_bittiming(dev, bt, btc);
>>>  	}
>> 	} else {
>> 		err = -EINVAL;
>> 	}
> 
> I don't have a strong preference on my implementation.
> 
> But IMHO your suggested changes only add additional code and additional
> comparisons in the if statement.
> 
> I don't see a benefit in your suggestions :-(

You have 3 seperate if()s and an implicit error value from the
initialisation. This is IMHO more straight forward:

	if (!bt->tq && bt->bitrate)
		err = can_calc_bittiming(dev, bt, btc);
	else if (bt->tq && !bt->bitrate)
		err = can_fixup_bittiming(dev, bt, btc);
	else
		err = -EINVAL;

Marc

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