On Tue, 2022-04-12 at 06:51 +0000, Miaoqian Lin wrote:
> wait_for_completion_timeout() returns unsigned long not long.
> it returns 0 if timed out, and positive if completed.
> The check for <= 0 is ambiguous and should be == 0 here
> indicating timeout which is the only error case
>
> Fixes: e813dde6f833 ("iio: stmpe-adc: Use
> wait_for_completion_timeout")
> Signed-off-by: Miaoqian Lin <linmq006@xxxxxxxxx>
Reviewed-by: Philippe Schenker <philippe.schenker@xxxxxxxxxxx>
> ---
> changes in v2:
> - Fix same issue in stmpe_read_temp.
> ---
> changes in v3:
> - update the patch subject.
> ---
> drivers/iio/adc/stmpe-adc.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
> index d2d405388499..83e0ac4467ca 100644
> --- a/drivers/iio/adc/stmpe-adc.c
> +++ b/drivers/iio/adc/stmpe-adc.c
> @@ -61,7 +61,7 @@ struct stmpe_adc {
> static int stmpe_read_voltage(struct stmpe_adc *info,
> struct iio_chan_spec const *chan, int *val)
> {
> - long ret;
> + unsigned long ret;
>
> mutex_lock(&info->lock);
>
> @@ -79,7 +79,7 @@ static int stmpe_read_voltage(struct stmpe_adc
> *info,
>
> ret = wait_for_completion_timeout(&info->completion,
> STMPE_ADC_TIMEOUT);
>
> - if (ret <= 0) {
> + if (ret == 0) {
> stmpe_reg_write(info->stmpe, STMPE_REG_ADC_INT_STA,
> STMPE_ADC_CH(info->channel));
> mutex_unlock(&info->lock);
> @@ -96,7 +96,7 @@ static int stmpe_read_voltage(struct stmpe_adc
> *info,
> static int stmpe_read_temp(struct stmpe_adc *info,
> struct iio_chan_spec const *chan, int *val)
> {
> - long ret;
> + unsigned long ret;
>
> mutex_lock(&info->lock);
>
> @@ -114,7 +114,7 @@ static int stmpe_read_temp(struct stmpe_adc *info,
>
> ret = wait_for_completion_timeout(&info->completion,
> STMPE_ADC_TIMEOUT);
>
> - if (ret <= 0) {
> + if (ret == 0) {
> mutex_unlock(&info->lock);
> return -ETIMEDOUT;
> }
