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usb: roles: Call try_module_get() from usb_role_switch_find_by_fwnode()

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commit 3a2a91a2d5 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: c6919d5e0c ("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>
This commit is contained in:
Hans de Goede 2021-04-09 14:41:36 +02:00 • committed by Greg Kroah-Hartman
commit eeb4fd46eb
1 changed files with 2 additions and 0 deletions
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2
drivers/usb/roles/class.c
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@ -189,6 +189,8 @@ usb_role_switch_find_by_fwnode(const struct fwnode_handle *fwnode)
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;
}