Re: [PATCH] mcb: Fix incorrect sanity check

Johannes Thumshirn
2025-11-20T11:48:49Z

On 11/20/25 12:37 PM, Jose Javier Rodriguez Barbarin wrote:
> __mcb_register_driver() makes some sanity checks over mcb_driver
> to check if .probe and .remove callbacks are set. However, not all
> mcb device drivers implement .remove callback.
>
> Remove .remove check to ensure all mcb device drivers can be loaded.

The only driver I can see that doesn't implement a .remove method is
gpio-menz127.c.

Is this safe?

>
> Signed-off-by: Jose Javier Rodriguez Barbarin <dev-josejavier.rodriguez@duagon.com>
> ---
> drivers/mcb/mcb-core.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mcb/mcb-core.c b/drivers/mcb/mcb-core.c
> index c1367223e71a..3d487d75c483 100644
> --- a/drivers/mcb/mcb-core.c
> +++ b/drivers/mcb/mcb-core.c
> @@ -85,7 +85,8 @@ static void mcb_remove(struct device *dev)
> struct mcb_device *mdev = to_mcb_device(dev);
> struct module *carrier_mod;
>
> - mdrv->remove(mdev);
> + if (mdrv->remove)
> + mdrv->remove(mdev);
>
> carrier_mod = mdev->dev.parent->driver->owner;
> module_put(carrier_mod);
> @@ -176,13 +177,13 @@ static const struct device_type mcb_carrier_device_type = {
> * @owner: The @mcb_driver's module
> * @mod_name: The name of the @mcb_driver's module
> *
> - * Register a @mcb_driver at the system. Perform some sanity checks, if
> - * the .probe and .remove methods are provided by the driver.
> + * Register a @mcb_driver at the system. Perform a sanity check, if
> + * .probe method is provided by the driver.
> */
> int __mcb_register_driver(struct mcb_driver *drv, struct module *owner,
> const char *mod_name)
> {
> - if (!drv->probe || !drv->remove)
> + if (!drv->probe)
> return -EINVAL;
>
> drv->driver.owner = owner;