Re: [PATCH] i3c: master: Fix of_node reference leak in i3c_master_register()

[Wentao Liang <vulab@iscas.ac.cn>]

Hi Frank,

Sorry for the very late reply.

Thank you for catching both problems. You are right, and I am sorry for
getting the API wrong in v1: the reference on the node is taken with
fwnode_handle_get(), so it has to be dropped with fwnode_handle_put().
of_node_put() only operates on Open Firmware nodes and is a no-op on ACPI
and software node systems, so the leak remained there.

On your second question: every other error branch in this function runs
after device_initialize(), and all of them end up at err_put_dev, where
put_device() calls i3c_masterdev_release() and that function drops the
fwnode with fwnode_handle_put(dev->fwnode). The i3c_master_rpm_get()
failure is the only path that returns before the device is initialized;
put_device() cannot be used there, so the reference has to be dropped
explicitly.

A v2 that calls fwnode_handle_put(dev_fwnode(&master->dev)), rebased on
current mainline, follows in a separate mail. I also dropped Cc: stable
there, since this only leaks on a registration failure path.

Thanks,
Wentao