Commit b787a3e7 authored by Xu Yang's avatar Xu Yang Committed by Greg Kroah-Hartman
Browse files

usb: roles: don't get/set_role() when usb_role_switch is unregistered 



There is a possibility that usb_role_switch device is unregistered before
the user put usb_role_switch. In this case, the user may still want to
get/set_role() since the user can't sense the changes of usb_role_switch.

This will add a flag to show if usb_role_switch is already registered and
avoid unwanted behaviors.

Fixes: fde0aa6c ("usb: common: Small class for USB role switches")
cc: stable@vger.kernel.org
Signed-off-by: default avatarXu Yang <xu.yang_2@nxp.com>
Acked-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240129093739.2371530-2-xu.yang_2@nxp.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 1c9be138

drivers/usb/roles/class.c

+10 −2
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ struct usb_role_switch { 
	struct mutex lock; /* device lock*/

	struct module *module; /* the module this device depends on */

	enum usb_role role;

	bool registered;



	/* From descriptor */

	struct device *usb2_port;
@@ -49,6 +50,9 @@ int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role) 
	if (IS_ERR_OR_NULL(sw))

		return 0;



	if (!sw->registered)

		return -EOPNOTSUPP;



	mutex_lock(&sw->lock);



	ret = sw->set(sw, role);
@@ -74,7 +78,7 @@ enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw) 
{

	enum usb_role role;



	if (IS_ERR_OR_NULL(sw))

	if (IS_ERR_OR_NULL(sw) || !sw->registered)

		return USB_ROLE_NONE;



	mutex_lock(&sw->lock);
@@ -357,6 +361,8 @@ usb_role_switch_register(struct device *parent, 
		return ERR_PTR(ret);

	}



	sw->registered = true;



	/* TODO: Symlinks for the host port and the device controller. */



	return sw;
@@ -371,9 +377,11 @@ EXPORT_SYMBOL_GPL(usb_role_switch_register); 
 */

void usb_role_switch_unregister(struct usb_role_switch *sw)

{

	if (!IS_ERR_OR_NULL(sw))

	if (!IS_ERR_OR_NULL(sw)) {

		sw->registered = false;

		device_unregister(&sw->dev);

	}

}

EXPORT_SYMBOL_GPL(usb_role_switch_unregister);



/**