Hi Alan,

quoted

So you mean if I do "hciconfig hci0 down", then the uart-bus should
"down" the tty and only on "hciconfig hci0 up" it should "up" the
tty? I would expect a uart-bus slave-device takes control of the
device ("up" it) on probe. It's hardwired anyway.

Today you can switch stacks at runtime, you can switch between the kernel
stack and debug tools at runtime. Breaking that is a regression.

actually that is not true. We have HCI User Channel since a long time that gives you raw access to the devices. And also kernel interfaces to do all vendor / debug tasks.

Regards

Marcel