[PATCH 5.4 296/411] iio: adc: stmpe-adc: Fix wait_for_completion_timeout return value check

Greg Kroah-Hartman
2022-06-13T11:39:48Z

From: Miaoqian Lin <linmq006@gmail.com>

[ Upstream commit d345b23200bcdbd2bd3582213d738c258b77718f ]

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@gmail.com>
Reviewed-by: Philippe Schenker <philippe.schenker@toradex.com>
Link: https://lore.kernel.org/r/20220412065150.14486-1-linmq006@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 bd72727fc417..35ae801c4d35 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;
}
--
2.35.1