Re: [PATCH/RFC] 8250: Auto RS485 direction control

Alan Cox
2008-07-24T13:17:47Z

> > So the 16550 sucks, that's not true of everyone elses uarts.
>
> It's true of all 8250 compatibles which don't have hardware RS485
> support. I think that's all of them except 16850 and 16960.

Its not true of a lot of other uart devices however.

> A while back, there were people asking for:
> 1. handshaking on DTR/DSR rather than RTS/CTS.
> 2. a different handshaking method for RTS/CTS (where you assert
> RTS to ask for permission to send when you actually have something
> to send.)
>
> Should CRTSCTS be a global "enable some kind of flow control" bit and
> setserial be used to configure the actual flow control method
> (conventional RTS/CTS, DTR/DSR, alternate RTS/CTS, RS485 on RTS,
> RS485 on DTR) ?

I've actually been trying to find out how other Unixen handle DTR/DSR and
not had any luck finding a sensible common interface for it.

Alan