Re: [PATCH] staging:iio:ad7280a: Use managed interfaces

[Jonathan Cameron]

On 19/07/14 11:33, Himangi Saraogi wrote:
> This patch moves data allocated using unmanaged interfaces to managed
> interfaces like devm_kzalloc, devm_iio_device_register, devm_kasprintf,
> devm_request_threaded_irq and does away with the calls to free the
> allocated memory in the probe and remove functions. Some labels in the
> probe function are also removed.
>
> Signed-off-by: Himangi Saraogi <himangi774@xxxxxxxxx>
cc'ing Lars who tends to look after Analog Devices drivers
and more specifically was involved in the thread that lead to this
patch.

Also, the devm_kasprintf does not appear to be in upstream so this
patch should have made an dependency clear.

https://lkml.org/lkml/2014/7/16/667

What is the intended merge path for that patch?


> ---
> I am not very sure if devmifying request_irq is a good idea as it
> leads to the freeing of the interrupt after the ad7280_write.
Agreed. I wouldn't do it!

Otherwise, all looks fine.
>   drivers/staging/iio/adc/ad7280a.c | 57 ++++++++++++++-------------------------
>   1 file changed, 20 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/staging/iio/adc/ad7280a.c b/drivers/staging/iio/adc/ad7280a.c
> index d215edf..3706b3e 100644
> --- a/drivers/staging/iio/adc/ad7280a.c
> +++ b/drivers/staging/iio/adc/ad7280a.c
> @@ -486,8 +486,8 @@ static int ad7280_channel_init(struct ad7280_state *st)
>   {
>   	int dev, ch, cnt;
>
> -	st->channels = kcalloc((st->slave_num + 1) * 12 + 2,
> -			       sizeof(*st->channels), GFP_KERNEL);
> +	st->channels = devm_kcalloc(&st->spi->dev, (st->slave_num + 1) * 12 + 2,
> +				    sizeof(*st->channels), GFP_KERNEL);
>   	if (st->channels == NULL)
>   		return -ENOMEM;
>
> @@ -547,8 +547,9 @@ static int ad7280_attr_init(struct ad7280_state *st)
>   {
>   	int dev, ch, cnt;
>
> -	st->iio_attr = kzalloc(sizeof(*st->iio_attr) * (st->slave_num + 1) *
> -				AD7280A_CELLS_PER_DEV * 2, GFP_KERNEL);
> +	st->iio_attr = devm_kzalloc(&st->spi->dev, sizeof(*st->iio_attr) *
> +				    (st->slave_num + 1) *
> +				    AD7280A_CELLS_PER_DEV * 2, GFP_KERNEL);
>   	if (st->iio_attr == NULL)
>   		return -ENOMEM;
>
> @@ -564,7 +565,7 @@ static int ad7280_attr_init(struct ad7280_state *st)
>   			st->iio_attr[cnt].dev_attr.store =
>   				ad7280_store_balance_sw;
>   			st->iio_attr[cnt].dev_attr.attr.name =
> -				kasprintf(GFP_KERNEL,
> +				devm_kasprintf(&st->spi->dev, GFP_KERNEL,
>   					"in%d-in%d_balance_switch_en",
>   					(dev * AD7280A_CELLS_PER_DEV) + ch,
>   					(dev * AD7280A_CELLS_PER_DEV) + ch + 1);
> @@ -581,7 +582,8 @@ static int ad7280_attr_init(struct ad7280_state *st)
>   			st->iio_attr[cnt].dev_attr.store =
>   				ad7280_store_balance_timer;
>   			st->iio_attr[cnt].dev_attr.attr.name =
> -				kasprintf(GFP_KERNEL, "in%d-in%d_balance_timer",
> +				devm_kasprintf(&st->spi->dev, GFP_KERNEL,
> +					"in%d-in%d_balance_timer",
>   					(dev * AD7280A_CELLS_PER_DEV) + ch,
>   					(dev * AD7280A_CELLS_PER_DEV) + ch + 1);
>   			ad7280_attributes[cnt] =
> @@ -900,48 +902,36 @@ static int ad7280_probe(struct spi_device *spi)
>
>   	ret = ad7280_attr_init(st);
>   	if (ret < 0)
> -		goto error_free_channels;
> +		return ret;
>
> -	ret = iio_device_register(indio_dev);
> +	ret = devm_iio_device_register(&spi->dev, indio_dev);
>   	if (ret)
> -		goto error_free_attr;
> +		return ret;
>
>   	if (spi->irq > 0) {
>   		ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
>   				   AD7280A_ALERT, 1,
>   				   AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN);
>   		if (ret)
> -			goto error_unregister;
> +			return ret;
>
>   		ret = ad7280_write(st, AD7280A_DEVADDR(st->slave_num),
>   				   AD7280A_ALERT, 0,
>   				   AD7280A_ALERT_GEN_STATIC_HIGH |
>   				   (pdata->chain_last_alert_ignore & 0xF));
>   		if (ret)
> -			goto error_unregister;
> -
> -		ret = request_threaded_irq(spi->irq,
> -					   NULL,
> -					   ad7280_event_handler,
> -					   IRQF_TRIGGER_FALLING |
> -					   IRQF_ONESHOT,
> -					   indio_dev->name,
> -					   indio_dev);
> +			return ret;
> +
> +		ret = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
> +						ad7280_event_handler,
> +						IRQF_TRIGGER_FALLING |
> +						IRQF_ONESHOT, indio_dev->name,
> +						indio_dev);
>   		if (ret)
> -			goto error_unregister;
> +			return ret;
>   	}
>
>   	return 0;
> -error_unregister:
> -	iio_device_unregister(indio_dev);
> -
> -error_free_attr:
> -	kfree(st->iio_attr);
> -
> -error_free_channels:
> -	kfree(st->channels);
> -
> -	return ret;
>   }
>
>   static int ad7280_remove(struct spi_device *spi)
> @@ -949,16 +939,9 @@ static int ad7280_remove(struct spi_device *spi)
>   	struct iio_dev *indio_dev = spi_get_drvdata(spi);
>   	struct ad7280_state *st = iio_priv(indio_dev);
>
> -	if (spi->irq > 0)
> -		free_irq(spi->irq, indio_dev);
> -	iio_device_unregister(indio_dev);
> -
>   	ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
>   			AD7280A_CTRL_HB_PWRDN_SW | st->ctrl_hb);
>
> -	kfree(st->channels);
> -	kfree(st->iio_attr);
> -
>   	return 0;
>   }

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