[PATCH] iio: proximity: rfd77402: Fix completion race condition in IRQ mode

[Felix Gu]

In IRQ mode, the completion was being reinitialized after the
measurement command had already been sent to the hardware. This
created a race condition where the IRQ handler could call complete()
before reinit_completion() was executed. Consequently,
wait_for_completion_timeout() would fail to see the signal and wait
until it timed out.

Move reinit_completion() to occur before the measurement command is
triggered to ensure the synchronization primitive is ready to
capture the interrupt.

Fixes: dc81be96a73a ("iio: proximity: rfd77402: Add interrupt handling support")
Signed-off-by: Felix Gu <ustc.gu@xxxxxxxxx>
---
 drivers/iio/proximity/rfd77402.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/proximity/rfd77402.c b/drivers/iio/proximity/rfd77402.c
index 6afdbfca3e5a..81b8daf17a54 100644
--- a/drivers/iio/proximity/rfd77402.c
+++ b/drivers/iio/proximity/rfd77402.c
@@ -173,10 +173,8 @@ static int rfd77402_wait_for_result(struct rfd77402_data *data)
 	struct i2c_client *client = data->client;
 	int val, ret;
 
-	if (data->irq_en) {
-		reinit_completion(&data->completion);
+	if (data->irq_en)
 		return rfd77402_wait_for_irq(data);
-	}
 
 	/*
 	 * As per RFD77402 datasheet section '3.1.1 Single Measure', the
@@ -204,6 +202,9 @@ static int rfd77402_measure(struct rfd77402_data *data)
 	if (ret < 0)
 		return ret;
 
+	if (data->irq_en)
+		reinit_completion(&data->completion);
+
 	ret = i2c_smbus_write_byte_data(client, RFD77402_CMD_R,
 					RFD77402_CMD_SINGLE |
 					RFD77402_CMD_VALID);

---
base-commit: c025f6cf4209e1542ec2afebe49f42bbaf1a5c7b
change-id: 20260304-77402-ec479de1b9f6

Best regards,
-- 
Felix Gu <ustc.gu@xxxxxxxxx>