Re: [PATCH] iio: light: ltr501: claim direct mode during raw writes

From: Jonathan Cameron
Date: Sat Oct 15 2016 - 11:12:27 EST


On 11/10/16 20:57, Alison Schofield wrote:
> Driver was checking for direct mode but not locking it. Use
> claim/release helper functions to guarantee the device stays
> in direct mode during all raw write operations.
>
> Signed-off-by: Alison Schofield <amsfield22@xxxxxxxxx>
Again, use of break to get out of the case code blocks, will
be more elegant than a goto which drops down several levels.

Otherwise, looks fine.
> ---
> drivers/iio/light/ltr501.c | 71 +++++++++++++++++++++++++++-------------------
> 1 file changed, 42 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c
> index 3afc53a..0f1032d 100644
> --- a/drivers/iio/light/ltr501.c
> +++ b/drivers/iio/light/ltr501.c
> @@ -729,8 +729,9 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
> int i, ret, freq_val, freq_val2;
> struct ltr501_chip_info *info = data->chip_info;
>
> - if (iio_buffer_enabled(indio_dev))
> - return -EBUSY;
> + ret = iio_device_claim_direct_mode(indio_dev);
> + if (ret)
> + return ret;
>
> switch (mask) {
> case IIO_CHAN_INFO_SCALE:
> @@ -739,39 +740,50 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
> i = ltr501_get_gain_index(info->als_gain,
> info->als_gain_tbl_size,
> val, val2);
> - if (i < 0)
> - return -EINVAL;
> + if (i < 0) {
> + ret = -EINVAL;
> + goto release;
> + }
>
> data->als_contr &= ~info->als_gain_mask;
> data->als_contr |= i << info->als_gain_shift;
>
> - return regmap_write(data->regmap, LTR501_ALS_CONTR,
> - data->als_contr);
> + ret = regmap_write(data->regmap, LTR501_ALS_CONTR,
> + data->als_contr);
> + goto release;
> case IIO_PROXIMITY:
> i = ltr501_get_gain_index(info->ps_gain,
> info->ps_gain_tbl_size,
> val, val2);
> - if (i < 0)
> - return -EINVAL;
> + if (i < 0) {
> + ret = -EINVAL;
> + goto release;
> + }
> data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;
> data->ps_contr |= i << LTR501_CONTR_PS_GAIN_SHIFT;
>
> - return regmap_write(data->regmap, LTR501_PS_CONTR,
> - data->ps_contr);
> + ret = regmap_write(data->regmap, LTR501_PS_CONTR,
> + data->ps_contr);
> + goto release;
> default:
> - return -EINVAL;
> + ret = -EINVAL;
> + goto release;
> }
> case IIO_CHAN_INFO_INT_TIME:
> switch (chan->type) {
> case IIO_INTENSITY:
> - if (val != 0)
> - return -EINVAL;
> + if (val != 0) {
> + ret = -EINVAL;
> + goto release;
> + }
> mutex_lock(&data->lock_als);
> i = ltr501_set_it_time(data, val2);
> mutex_unlock(&data->lock_als);
> - return i;
> + ret = i;
> + goto release;
> default:
> - return -EINVAL;
> + ret = -EINVAL;
> + goto release;
> }
> case IIO_CHAN_INFO_SAMP_FREQ:
> switch (chan->type) {
> @@ -779,45 +791,46 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
> ret = ltr501_als_read_samp_freq(data, &freq_val,
> &freq_val2);
> if (ret < 0)
> - return ret;
> + goto release;
>
> ret = ltr501_als_write_samp_freq(data, val, val2);
> if (ret < 0)
> - return ret;
> + goto release;
>
> /* update persistence count when changing frequency */
> ret = ltr501_write_intr_prst(data, chan->type,
> 0, data->als_period);
>
> if (ret < 0)
> - return ltr501_als_write_samp_freq(data,
> - freq_val,
> - freq_val2);
> - return ret;
> + ret = ltr501_als_write_samp_freq(data, freq_val,
> + freq_val2);
> + goto release;
> case IIO_PROXIMITY:
> ret = ltr501_ps_read_samp_freq(data, &freq_val,
> &freq_val2);
> if (ret < 0)
> - return ret;
> + goto release;
>
> ret = ltr501_ps_write_samp_freq(data, val, val2);
> if (ret < 0)
> - return ret;
> + goto release;
>
> /* update persistence count when changing frequency */
> ret = ltr501_write_intr_prst(data, chan->type,
> 0, data->ps_period);
>
> if (ret < 0)
> - return ltr501_ps_write_samp_freq(data,
> - freq_val,
> - freq_val2);
> - return ret;
> + ret = ltr501_ps_write_samp_freq(data, freq_val,
> + freq_val2);
> + goto release;
> default:
> - return -EINVAL;
> + ret = -EINVAL;
> + goto release;
> }
> }
> - return -EINVAL;
> +release:
> + iio_device_release_direct_mode(indio_dev);
> + return ret;
> }
>
> static int ltr501_read_thresh(struct iio_dev *indio_dev,
>