linux-kernel - [PATCH] hwmod: (pmbus) disable PEC if not enabled

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Message-ID: <20220419205228.303952-1-dev_public@wujek.eu>
Date:   Tue, 19 Apr 2022 20:53:03 +0000
From:   Adam Wujek <dev_public@...ek.eu>
To:     unlisted-recipients:; (no To-header on input)
Cc:     Adam Wujek <dev_public@...ek.eu>,
        Guenter Roeck <linux@...ck-us.net>,
        Jean Delvare <jdelvare@...e.com>, linux-hwmon@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] hwmod: (pmbus) disable PEC if not enabled

Explicitly disable PEC when the client does not support it.
Without the explicit disable, when the device with the PEC support is removed
later when a device without PEC support is inserted into the same address,
the driver uses the old value of client->flags which contains the I2C_CLIENT_PEC
flag. As a consequence the PEC is used when it should not.

Signed-off-by: Adam Wujek <dev_public@...ek.eu>
---
 drivers/hwmon/pmbus/pmbus_core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 82c3754e21e3..f8ca36759b0a 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -2014,6 +2014,8 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
 	ret = i2c_smbus_read_byte_data(client, PMBUS_CAPABILITY);
 	if (ret >= 0 && (ret & PB_CAPABILITY_ERROR_CHECK))
 		client->flags |= I2C_CLIENT_PEC;
+	else
+		client->flags &= ~I2C_CLIENT_PEC;

 	pmbus_clear_faults(client);

--
2.17.1