[PATCH v2] iio: stmpe-adc: Fix wait_for_completion_timeout return value check

From: Miaoqian Lin
Date: Mon Apr 11 2022 - 21:56:42 EST


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>
---
changes in v2:
- Fix same issue in stmpe_read_temp.
---
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;
}
--
2.17.1