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From:   Miaoqian Lin <linmq006@gmail.com>
To:     Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@foss.st.com>,
        Kees Cook <keescook@chromium.org>,
        Miaoqian Lin <linmq006@gmail.com>,
        Philippe Schenker <philippe.schenker@toradex.com>,
        linux-iio@vger.kernel.org,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] iio: stmpe-adc: Fix wait_for_completion_timeout return value check
Date:   Mon, 11 Apr 2022 10:30:27 +0000
Message-Id: <20220411103032.14038-1-linmq006@gmail.com>
Precedence: bulk

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>
---
 drivers/iio/adc/stmpe-adc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/stmpe-adc.c b/drivers/iio/adc/stmpe-adc.c
index d2d405388499..d475d1c17bfc 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);
-- 
2.17.1