On Mon, May 02, 2022 at 10:04:56AM +0200, Uwe Kleine-König wrote:
> 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@xxxxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> 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
>
