Re: USB output in ucom

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

On Tue, Jul 15, 2025 at 03:41:16PM -0000, Michael van Elst wrote:
> It can only work if USB is used in polling mode, which usually also means
> that you must not use that USB controller for anything else.

I note support for USB polling is already present for ukbd to be
used as console input. It seeùs it would not be very complicated
to use the same logic for console input.

On the ouput side, I got some success with cnputc feeding a
thread through a ring buffer, and the thread takes care of USB
output. That will not work in DDB though, since the thread 
will not have the opportunity to get sceduled.

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost