rfc2217 Support

[bluespider42]

RFC2217 has never worked with the async version of pyserial.
Could this be added?
This is the only reason I'm stuck on 2024.3.2 for the pre-async version of pyserial.
pyserial#46
pyserial#95

[puddly]

I think the referenced PR rewrites the internals of pyserial-asyncio to use poll-based reading and writing, as opposed to using the event loop for reads and writes. With a polling rate of 0.0005, this would introduce a lot of unnecessary context switching.

Truthfully, I don't think the current approach of hacking in async support is really scalable beyond file descriptor based serial ports. We already special case away serial-over-TCP and I think the same would need to be done for Telnet.

I've been slowly working on an independent serial library (https://github.com/puddly/serialpy) but it's still very WIP. If you want to try and implement a RFC2217 client without IO, we can try to add it in.

[bluespider42]

Thanks for the response - I understand why things moved this way but I don't think my python async is up to the task! - I'm just hopeful I'm not the only one in this situation.