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From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Guenter Roeck <linux@roeck-us.net>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Jun Li <jun.li@nxp.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-usb@vger.kernel.org, kernel@pengutronix.de
Subject: [PATCH] usb: typec: tcpci: Don't skip cleanup in .remove() on error
Date: Mon,  2 May 2022 10:04:56 +0200	[thread overview]
Message-ID: <20220502080456.21568-1-u.kleine-koenig@pengutronix.de> (raw)

Returning an error value in an i2c remove callback results in an error
message being emitted by the i2c core, but otherwise it doesn't make a
difference. The device goes away anyhow and the devm cleanups are
called.

In this case the remove callback even returns early without stopping the
tcpm worker thread and various timers. A work scheduled on the work
queue, or a firing timer after tcpci_remove() returned probably results
in a use-after-free situation because the regmap and driver data were
freed. So better make sure that tcpci_unregister_port() is called even
if disabling the irq failed.

Also emit a more specific error message instead of the i2c core's
"remove failed (EIO), will be ignored" and return 0 to suppress the
core's warning.

This patch is (also) a preparation for making i2c remove callbacks
return void.

Fixes: 3ba76256fc4e ("usb: typec: tcpci: mask event interrupts when remove driver")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/usb/typec/tcpm/tcpci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index e07d26a3cd8e..f33e08eb7670 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -877,7 +877,7 @@ static int tcpci_remove(struct i2c_client *client)
 	/* Disable chip interrupts before unregistering port */
 	err = tcpci_write16(chip->tcpci, TCPC_ALERT_MASK, 0);
 	if (err < 0)
-		return err;
+		dev_warn(&client->dev, "Failed to disable irqs (%pe)\n", ERR_PTR(err));
 
 	tcpci_unregister_port(chip->tcpci);
 

base-commit: 3123109284176b1532874591f7c81f3837bbdc17
-- 
2.35.1


             reply	other threads:[~2022-05-02  8:06 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-02  8:04 Uwe Kleine-König [this message]
2022-05-02 12:27 ` [PATCH] usb: typec: tcpci: Don't skip cleanup in .remove() on error Heikki Krogerus
2022-05-02 13:30 ` Guenter Roeck
2022-05-05 21:26 ` Guenter Roeck

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