From: Hans de Goede hdegoede@redhat.com
commit 3a2a91a2d51761557843996a66098eb7182b48b4 upstream.
usb_role_switch_find_by_fwnode() returns a reference to the role-switch which must be put by calling usb_role_switch_put().
usb_role_switch_put() calls module_put(sw->dev.parent->driver->owner), add a matching try_module_get() to usb_role_switch_find_by_fwnode(), making it behave the same as the other usb_role_switch functions which return a reference.
This avoids a WARN_ON being hit at kernel/module.c:1158 due to the module-refcount going below 0.
Fixes: c6919d5e0cd1 ("usb: roles: Add usb_role_switch_find_by_fwnode()") Cc: stable stable@vger.kernel.org Reviewed-by: Guenter Roeck linux@roeck-us.net Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Signed-off-by: Hans de Goede hdegoede@redhat.com Link: https://lore.kernel.org/r/20210409124136.65591-1-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/roles/class.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/usb/roles/class.c +++ b/drivers/usb/roles/class.c @@ -189,6 +189,8 @@ usb_role_switch_find_by_fwnode(const str return NULL;
dev = class_find_device_by_fwnode(role_class, fwnode); + if (dev) + WARN_ON(!try_module_get(dev->parent->driver->owner));
return dev ? to_role_switch(dev) : NULL; }