linux-kernel - [PATCH v2] iio: light: cm32181: Unregister second I2C client if present

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Message-Id: <20230208072141.1103738-1-kai.heng.feng@canonical.com>
Date:   Wed,  8 Feb 2023 15:21:41 +0800
From:   Kai-Heng Feng <kai.heng.feng@...onical.com>
To:     ktsai@...ellamicro.com, jic23@...nel.org, lars@...afoo.de
Cc:     hdegoede@...hat.com, Kai-Heng Feng <kai.heng.feng@...onical.com>,
        linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2] iio: light: cm32181: Unregister second I2C client if present

If a second client that talks to the actual I2C address was created in
probe(), there should be a corresponding cleanup in remove() to avoid
leakage.

So if the "client" is not the same one used by I2C core, unregister it
accordingly.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2152281
Fixes: c1e62062ff54 ("iio: light: cm32181: Handle CM3218 ACPI devices with 2 I2C resources")
Signed-off-by: Kai-Heng Feng <kai.heng.feng@...onical.com>
---
v2:
 - Use devm_add_action_or_reset() instead of remove() callback to avoid
   race.

 drivers/iio/light/cm32181.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
index b1674a5bfa368..a3e5f56101c9f 100644
--- a/drivers/iio/light/cm32181.c
+++ b/drivers/iio/light/cm32181.c
@@ -429,6 +429,16 @@ static const struct iio_info cm32181_info = {
 	.attrs			= &cm32181_attribute_group,
 };
 
+static void cm32181_disable(void *data)
+{
+	struct i2c_client *client = data;
+	struct cm32181_chip *cm32181 = iio_priv(i2c_get_clientdata(client));
+
+	/* Unregister the dummy client */
+	if (cm32181->client != client)
+		i2c_unregister_device(cm32181->client);
+}
+
 static int cm32181_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
@@ -479,6 +489,12 @@ static int cm32181_probe(struct i2c_client *client)
 		return ret;
 	}
 
+	ret = devm_add_action_or_reset(dev, cm32181_disable, client);
+	if (ret) {
+		dev_err(dev, "%s: add devres action failed\n", __func__);
+		return ret;
+	}
+
 	ret = devm_iio_device_register(dev, indio_dev);
 	if (ret) {
 		dev_err(dev, "%s: regist device failed\n", __func__);
-- 
2.34.1