Re: [RFC PATCH 0/3] UART slave device bus

quoted

That would still be a regression. Not everyone even uses the kernel
bluetooth stack. It would only return EBUSY if you had done an "up"
on it via the direct bluetooth stack.  

So it returns EBUSY when uart-bus is used. Since uart-bus is about
hardwired devices that's basically always.

That would only be when the bluetooth port in question was active via the
hardwired interface - which is not always. You choose to turn on/off
bluetooth interfaces. If you boot with an older user space you'd use
hciattach instead.

In many cases you'll also still need the tty interface to do things like
firmware upgrades.

Alan