Re: [PATCH 05/11] staging: iio: ad2s1200: Introduce variable for repeated value

[David Julian Veenstra <davidjulianveenstra@gmail.com>]

On 23, March 2018 14:17, Jonathan Cameron wrote:

> On Sun, 18 Mar 2018 14:35:46 +0100
> David Veenstra <davidjulianveenstra@gmail.com> wrote:
>
>> Add variable to hold &spi->dev in ad2s1200_probe. This value is repeatedly
>> used in ad2s1200_probe.
>> 
>> Signed-off-by: David Veenstra <davidjulianveenstra@gmail.com>
> I'm a little unconvinced by this one. It adds code to save
> a really very trivial bit of repetition.  If it had been
> via another pointer or this would have made a big difference
> in number of lines by bringing a lot of entries below 80 chars
> that weren't previous, then there would be a good argument.
>
> Here, not so much.

The 9th patch adds another 4 occurrences. So in total &st->dev appears
9 times in ad2s1200_probe. To me it seemed worth it to
introduce a variable for it. But I agree that it doesn't add much.

Best regards,
David Veenstra

>
> Jonathan
>> ---
>>  drivers/staging/iio/resolver/ad2s1200.c | 13 ++++++++-----
>>  1 file changed, 8 insertions(+), 5 deletions(-)
>> 
>> diff --git a/drivers/staging/iio/resolver/ad2s1200.c b/drivers/staging/iio/resolver/ad2s1200.c
>> index 00efba598671..eceb86e952de 100644
>> --- a/drivers/staging/iio/resolver/ad2s1200.c
>> +++ b/drivers/staging/iio/resolver/ad2s1200.c
>> @@ -118,19 +118,22 @@ static int ad2s1200_probe(struct spi_device *spi)
>>  	unsigned short *pins = spi->dev.platform_data;
>>  	struct ad2s1200_state *st;
>>  	struct iio_dev *indio_dev;
>> +	struct device *dev;
>>  	int pn, ret = 0;
>>  
>> +	dev = &spi->dev;
>> +
>>  	for (pn = 0; pn < AD2S1200_PN; pn++) {
>> -		ret = devm_gpio_request_one(&spi->dev, pins[pn], GPIOF_DIR_OUT,
>> +		ret = devm_gpio_request_one(dev, pins[pn], GPIOF_DIR_OUT,
>>  					    DRV_NAME);
>>  		if (ret) {
>> -			dev_err(&spi->dev, "request gpio pin %d failed\n",
>> +			dev_err(dev, "request gpio pin %d failed\n",
>>  				pins[pn]);
>>  			return ret;
>>  		}
>>  	}
>>  
>> -	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
>> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
>>  	if (!indio_dev)
>>  		return -ENOMEM;
>>  
>> @@ -141,14 +144,14 @@ static int ad2s1200_probe(struct spi_device *spi)
>>  	st->sample = pins[0];
>>  	st->rdvel = pins[1];
>>  
>> -	indio_dev->dev.parent = &spi->dev;
>> +	indio_dev->dev.parent = dev;
>>  	indio_dev->info = &ad2s1200_info;
>>  	indio_dev->modes = INDIO_DIRECT_MODE;
>>  	indio_dev->channels = ad2s1200_channels;
>>  	indio_dev->num_channels = ARRAY_SIZE(ad2s1200_channels);
>>  	indio_dev->name = spi_get_device_id(spi)->name;
>>  
>> -	ret = devm_iio_device_register(&spi->dev, indio_dev);
>> +	ret = devm_iio_device_register(dev, indio_dev);
>>  	if (ret)
>>  		return ret;
>>