can't download Oceanic VT3 on linux

[Linus Torvalds]

On Wed, Mar 12, 2014 at 7:32 AM, Jef Driesen <jef at libdivecomputer.org> wrote:
>
> With USB being the Universal *Serial* Bus, it's kind of funny that one thing
> it doesn't do very well is serial communication :-)

You spelled "sad" wrong.

> Isn't USB CDC-ACM supposed to be the standardized way for emulating legacy
> serial communication over USB?

That is indeed supposed to be the standardized way to implement
almost-legacy serial communications over USB.  But it's not really a
"cable replacement" standard, it tries to go further than that, which
is probably why pure cable replacements seem to never use it.

As you mention, it *does* get used by people who actually end up
implementing real USB on the other side.

So it is commonly used as a "virtual serial port" by people who
actually implement USB natively but I've actually never seen it in an
actual *physical* USB to serial port converter.

I'm not 100% sure why, but I suspect it is due to CDC-ACM simply being
over-engineered for the solution, resulting in both unnecessarily
complex silicon and various driver problems. It may also have been
late to the party, and by the time it arrived there were three or four
vendors who had solved it their own way. And then it just remained
that way.

                         Linus