linux-kernel - [PATCH v3] iio: light: cm32181: Unregister second I2C client if present

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Date:   Thu, 23 Feb 2023 00:24:08 +0800
From:   Kai-Heng Feng <kai.heng.feng@...onical.com>
To:     jic23@...nel.org, lars@...afoo.de
Cc:     hdegoede@...hat.com, Kai-Heng Feng <kai.heng.feng@...onical.com>,
        Kevin Tsai <ktsai@...ellamicro.com>, linux-iio@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v3] iio: light: cm32181: Unregister second I2C client if present

If a second dummy client that talks to the actual I2C address was
created in probe(), there should be a proper cleanup on driver and
device removal to avoid leakage.

So unregister the dummy client via another callback.

Suggested-by: Hans de Goede <hdegoede@...hat.com>
Fixes: c1e62062ff54 ("iio: light: cm32181: Handle CM3218 ACPI devices with 2 I2C resources")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2152281
Signed-off-by: Kai-Heng Feng <kai.heng.feng@...onical.com>
---
v3:
 - Use devm_add_action_or_reset() in a correct place.
 - Wording.

v2:
 - Use devm_add_action_or_reset() instead of remove() callback to avoid
   race.

 drivers/iio/light/cm32181.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
index b1674a5bfa368..b3da7a517aaea 100644
--- a/drivers/iio/light/cm32181.c
+++ b/drivers/iio/light/cm32181.c
@@ -429,6 +429,14 @@ static const struct iio_info cm32181_info = {
 	.attrs			= &cm32181_attribute_group,
 };
 
+static void cm32181_unregister_dummy_client(void *data)
+{
+	struct i2c_client *client = data;
+
+	/* Unregister the dummy client */
+	i2c_unregister_device(client);
+}
+
 static int cm32181_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
@@ -460,6 +468,12 @@ static int cm32181_probe(struct i2c_client *client)
 		client = i2c_acpi_new_device(dev, 1, &board_info);
 		if (IS_ERR(client))
 			return PTR_ERR(client);
+
+		ret = devm_add_action_or_reset(dev, cm32181_unregister_dummy_client, client);
+		if (ret) {
+			dev_err(dev, "%s: add devres action failed\n", __func__);
+			return ret;
+		}
 	}
 
 	cm32181 = iio_priv(indio_dev);
-- 
2.34.1