On Mon, 29 Oct 2018 17:52:41 +0100
Slawomir Stepien <sst@xxxxxxxxx> wrote:
> devm_* APIs are device managed and make code simpler.
>
> Signed-off-by: Slawomir Stepien <sst@xxxxxxxxx>
Very nearly perfect (I think).
But there is one path where we don't quite manage to clean everything up.
> ---
Also, I should be seeing a version log here to avoid me having to look back
at previous versions (potentially) to remind me what needed changing.
Thanks,
Jonathan
> drivers/staging/iio/adc/ad7280a.c | 95 +++++++++++++------------------
> 1 file changed, 39 insertions(+), 56 deletions(-)
>
> diff --git a/drivers/staging/iio/adc/ad7280a.c b/drivers/staging/iio/adc/ad7280a.c
> index b736275c10f5..1263b70693ed 100644
> --- a/drivers/staging/iio/adc/ad7280a.c
> +++ b/drivers/staging/iio/adc/ad7280a.c
> @@ -342,6 +342,14 @@ static int ad7280_read_all_channels(struct ad7280_state *st, unsigned int cnt,
> return sum;
> }
>
> +static void ad7280_sw_power_down(void *data)
> +{
> + struct ad7280_state *st = data;
> +
> + ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
> + AD7280A_CTRL_HB_PWRDN_SW | st->ctrl_hb);
> +}
> +
> static int ad7280_chain_setup(struct ad7280_state *st)
> {
> unsigned int val, n;
> @@ -492,8 +500,8 @@ 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)
> return -ENOMEM;
>
> @@ -552,16 +560,18 @@ static int ad7280_channel_init(struct ad7280_state *st)
> static int ad7280_attr_init(struct ad7280_state *st)
> {
> int dev, ch, cnt;
> + unsigned int index;
>
> - st->iio_attr = kcalloc(2, sizeof(*st->iio_attr) *
> - (st->slave_num + 1) * AD7280A_CELLS_PER_DEV,
> - GFP_KERNEL);
> + st->iio_attr = devm_kcalloc(&st->spi->dev, 2, sizeof(*st->iio_attr) *
> + (st->slave_num + 1) * AD7280A_CELLS_PER_DEV,
> + GFP_KERNEL);
> if (!st->iio_attr)
> return -ENOMEM;
>
> for (dev = 0, cnt = 0; dev <= st->slave_num; dev++)
> for (ch = AD7280A_CELL_VOLTAGE_1; ch <= AD7280A_CELL_VOLTAGE_6;
> ch++, cnt++) {
> + index = dev * AD7280A_CELLS_PER_DEV + ch;
> st->iio_attr[cnt].address =
> ad7280a_devaddr(dev) << 8 | ch;
> st->iio_attr[cnt].dev_attr.attr.mode =
> @@ -571,10 +581,9 @@ 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,
> - "in%d-in%d_balance_switch_en",
> - dev * AD7280A_CELLS_PER_DEV + ch,
> - dev * AD7280A_CELLS_PER_DEV + ch + 1);
> + devm_kasprintf(&st->spi->dev, GFP_KERNEL,
> + "in%d-in%d_balance_switch_en",
> + index, index + 1);
> ad7280_attributes[cnt] =
> &st->iio_attr[cnt].dev_attr.attr;
> cnt++;
> @@ -588,10 +597,9 @@ 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",
> - dev * AD7280A_CELLS_PER_DEV + ch,
> - dev * AD7280A_CELLS_PER_DEV + ch + 1);
> + devm_kasprintf(&st->spi->dev, GFP_KERNEL,
> + "in%d-in%d_balance_timer",
> + index, index + 1);
> ad7280_attributes[cnt] =
> &st->iio_attr[cnt].dev_attr.attr;
> }
> @@ -909,65 +917,41 @@ 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_add_action(&spi->dev, ad7280_sw_power_down, st);
> if (ret)
What state are we left in if the devm_add_action fails?
Answer: Everything is unwound except the thing we were adding the action
for. So you need to call ad7280_sw_power_down in the error path here.
> - goto error_free_attr;
> + return ret;
> +
> + ret = devm_iio_device_register(&spi->dev, indio_dev);
> + if (ret)
> + 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)
> -{
> - 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;
> }
>
> @@ -982,7 +966,6 @@ static struct spi_driver ad7280_driver = {
> .name = "ad7280",
> },
> .probe = ad7280_probe,
> - .remove = ad7280_remove,
> .id_table = ad7280_id,
> };
> module_spi_driver(ad7280_driver);
