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From:   Miaoqian Lin <linmq006@gmail.com>
To:     Song Qiang <songqiang1304521@gmail.com>,
        Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Ivan Drobyshevskyi <drobyshevskyi@gmail.com>,
        linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     linmq006@gmail.com
Subject: [PATCH v2] iio: proximity: vl53l0x:  Fix return value check of wait_for_completion_timeout
Date:   Tue, 12 Apr 2022 06:42:09 +0000
Message-Id: <20220412064210.10734-1-linmq006@gmail.com>
In-Reply-To: <PH0PR03MB6786F62DE142E3E2C66C937F99ED9@PH0PR03MB6786.namprd03.prod.outlook.com>
References: <PH0PR03MB6786F62DE142E3E2C66C937F99ED9@PH0PR03MB6786.namprd03.prod.outlook.com>
Precedence: bulk

wait_for_completion_timeout() returns unsigned long not int.
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: 3cef2e31b54b ("iio: proximity: vl53l0x: Add IRQ support")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
Changes in v2:
- add driver name in patch subject.
---
 drivers/iio/proximity/vl53l0x-i2c.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c
index 661a79ea200d..a284b20529fb 100644
--- a/drivers/iio/proximity/vl53l0x-i2c.c
+++ b/drivers/iio/proximity/vl53l0x-i2c.c
@@ -104,6 +104,7 @@ static int vl53l0x_read_proximity(struct vl53l0x_data *data,
 	u16 tries = 20;
 	u8 buffer[12];
 	int ret;
+	unsigned long time_left;
 
 	ret = i2c_smbus_write_byte_data(client, VL_REG_SYSRANGE_START, 1);
 	if (ret < 0)
@@ -112,10 +113,8 @@ static int vl53l0x_read_proximity(struct vl53l0x_data *data,
 	if (data->client->irq) {
 		reinit_completion(&data->completion);
 
-		ret = wait_for_completion_timeout(&data->completion, HZ/10);
-		if (ret < 0)
-			return ret;
-		else if (ret == 0)
+		time_left = wait_for_completion_timeout(&data->completion, HZ/10);
+		if (time_left == 0)
 			return -ETIMEDOUT;
 
 		vl53l0x_clear_irq(data);
-- 
2.17.1