Re: 2.6.25.3: serial problem (minicom)

Alan Cox
2008-06-16T10:31:20Z

> But, then, what is the relationship between CLOCAL and DTR/RTS supposed to
> be? Presumably, it should prevent a SIGHUP from being raised when DSR
> goes low, but beyond that, it all seems rather ill-defined. Throw in B0,

CLOCAL is defined to "ignore modem control lines"

> which the SUS strongly implies should unconditionally lower DTR and RTS,
> and the CRTSCTS flag, and the waters really get murky. It looks to me
> like the only thing you can say for certain is that CLOCAL will cause DSR
> to be ignored...and for anything else you're on your own.

Whatever it implies the behaviour should not have changed between 2.6.24
and 2.6.25. Nobody AFAIK sat down and decided to change it.

>
> Mind you, all this just suggests that POSIX kinda sucks, which is hardly
> an earth-shattering revelation.

Standards are part written spec and a large part an existing tradition
around that standard. The tradition is often the most important bit.

Alan