On Sun, 7 Apr 2024 19:29:17 +0200
Vasileios Amoiridis <vassilisamir@xxxxxxxxx> wrote:
> Introduce new linux/cleanup.h with the guard(mutex) functionality
> in the {read,write}_raw() functions.
>
> Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Suggested-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Signed-off-by: Vasileios Amoiridis <vassilisamir@xxxxxxxxx>
A could of corners of dead code that you can remove.
In general looks good.
Jonathan
> ---
> drivers/iio/pressure/bmp280-core.c | 129 +++++++++++++----------------
> 1 file changed, 58 insertions(+), 71 deletions(-)
>
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 50bdf79011bc..51bcdf8cede6 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -27,6 +27,7 @@
>
> #include <linux/bitops.h>
> #include <linux/bitfield.h>
> +#include <linux/cleanup.h>
> #include <linux/completion.h>
> #include <linux/delay.h>
> #include <linux/device.h>
> @@ -499,77 +500,69 @@ static int bme280_read_humid(struct bmp280_data *data, int *val, int *val2)
> return IIO_VAL_INT;
> }
>
> -static int bmp_read_raw(struct iio_dev *indio_dev,
> - struct iio_chan_spec const *chan,
> - int *val, int *val2, long mask)
> +static int bmp_read_raw_impl(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> {
> struct bmp280_data *data = iio_priv(indio_dev);
> - int ret;
>
> - pm_runtime_get_sync(data->dev);
> - mutex_lock(&data->lock);
> + guard(mutex)(&data->lock);
>
> switch (mask) {
> case IIO_CHAN_INFO_PROCESSED:
> switch (chan->type) {
> case IIO_HUMIDITYRELATIVE:
> - ret = data->chip_info->read_humid(data, val, val2);
> - break;
> + return data->chip_info->read_humid(data, val, val2);
> case IIO_PRESSURE:
> - ret = data->chip_info->read_press(data, val, val2);
> - break;
> + return data->chip_info->read_press(data, val, val2);
> case IIO_TEMP:
> - ret = data->chip_info->read_temp(data, val, val2);
> - break;
> + return data->chip_info->read_temp(data, val, val2);
> default:
> - ret = -EINVAL;
> - break;
> + return -EINVAL;
> }
> - break;
> case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> switch (chan->type) {
> case IIO_HUMIDITYRELATIVE:
> *val = 1 << data->oversampling_humid;
> - ret = IIO_VAL_INT;
> - break;
> + return IIO_VAL_INT;
> case IIO_PRESSURE:
> *val = 1 << data->oversampling_press;
> - ret = IIO_VAL_INT;
> - break;
> + return IIO_VAL_INT;
> case IIO_TEMP:
> *val = 1 << data->oversampling_temp;
> - ret = IIO_VAL_INT;
> - break;
> + return IIO_VAL_INT;
> default:
> - ret = -EINVAL;
> - break;
> + return -EINVAL;
> }
> - break;
> case IIO_CHAN_INFO_SAMP_FREQ:
> - if (!data->chip_info->sampling_freq_avail) {
> - ret = -EINVAL;
> - break;
> - }
> + if (!data->chip_info->sampling_freq_avail)
> + return -EINVAL;
>
> *val = data->chip_info->sampling_freq_avail[data->sampling_freq][0];
> *val2 = data->chip_info->sampling_freq_avail[data->sampling_freq][1];
> - ret = IIO_VAL_INT_PLUS_MICRO;
> - break;
> + return IIO_VAL_INT_PLUS_MICRO;
> case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> - if (!data->chip_info->iir_filter_coeffs_avail) {
> - ret = -EINVAL;
> - break;
> - }
> + if (!data->chip_info->iir_filter_coeffs_avail)
> + return -EINVAL;
>
> *val = (1 << data->iir_filter_coeff) - 1;
> - ret = IIO_VAL_INT;
> - break;
> + return IIO_VAL_INT;
> default:
> - ret = -EINVAL;
> - break;
> + return -EINVAL;
> }
>
> - mutex_unlock(&data->lock);
> + return 0;
As below. I don't think you can get here. I hope all paths have already returned.
> +}
> +
> +static int bmp_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct bmp280_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + pm_runtime_get_sync(data->dev);
> + ret = bmp_read_raw_impl(indio_dev, chan, val, val2, mask);
> pm_runtime_mark_last_busy(data->dev);
> pm_runtime_put_autosuspend(data->dev);
>
> @@ -697,12 +690,13 @@ static int bmp_write_iir_filter_coeffs(struct bmp280_data *data, int val)
> return -EINVAL;
> }
>
> -static int bmp_write_raw(struct iio_dev *indio_dev,
> - struct iio_chan_spec const *chan,
> - int val, int val2, long mask)
> +static int bmp_write_raw_impl(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long mask)
> {
> struct bmp280_data *data = iio_priv(indio_dev);
> - int ret = 0;
> +
> + guard(mutex)(&data->lock);
>
> /*
> * Helper functions to update sensor running configuration.
> @@ -712,46 +706,39 @@ static int bmp_write_raw(struct iio_dev *indio_dev,
> */
> switch (mask) {
> case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> - pm_runtime_get_sync(data->dev);
> - mutex_lock(&data->lock);
> switch (chan->type) {
> case IIO_HUMIDITYRELATIVE:
> - ret = bmp_write_oversampling_ratio_humid(data, val);
> - break;
> + return bmp_write_oversampling_ratio_humid(data, val);
> case IIO_PRESSURE:
> - ret = bmp_write_oversampling_ratio_press(data, val);
> - break;
> + return bmp_write_oversampling_ratio_press(data, val);
> case IIO_TEMP:
> - ret = bmp_write_oversampling_ratio_temp(data, val);
> - break;
> + return bmp_write_oversampling_ratio_temp(data, val);
> default:
> - ret = -EINVAL;
> - break;
> + return -EINVAL;
> }
> - mutex_unlock(&data->lock);
> - pm_runtime_mark_last_busy(data->dev);
> - pm_runtime_put_autosuspend(data->dev);
> - break;
> case IIO_CHAN_INFO_SAMP_FREQ:
> - pm_runtime_get_sync(data->dev);
> - mutex_lock(&data->lock);
> - ret = bmp_write_sampling_frequency(data, val, val2);
> - mutex_unlock(&data->lock);
> - pm_runtime_mark_last_busy(data->dev);
> - pm_runtime_put_autosuspend(data->dev);
> - break;
> + return bmp_write_sampling_frequency(data, val, val2);
> case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> - pm_runtime_get_sync(data->dev);
> - mutex_lock(&data->lock);
> - ret = bmp_write_iir_filter_coeffs(data, val);
> - mutex_unlock(&data->lock);
> - pm_runtime_mark_last_busy(data->dev);
> - pm_runtime_put_autosuspend(data->dev);
> - break;
> + return bmp_write_iir_filter_coeffs(data, val);
> default:
> return -EINVAL;
> }
>
> + return 0;
I'm fairly sure you can't get here so this is dead code. Hene
drop this final return.
> +}
>
