Re: Bug in serial line hangup code ?

Andrew E. Mileski (
Thu, 9 May 1996 12:29:58 -0400 (EDT)

> ppp enables hangup, and on hangup closes the port. The serial driver
> sets info.count to 0 on hangup, even though my program still has the
> port open. As my program watches info.count to determine if another
> process has the line is open, this is a bit of a problem.
> This is the way the serial driver is *designed*. Once a hangup has
> occurred, programs do not logically have the port "open". Access to the
> file descriptors has been revoked, and so they no longer can read or
> write to the serial port.

PMFJI, if I recall the start of the thread (I may be completely wrong),
the idea is to allow serial port monitoring? Why not just have the
info available via /proc/serial/0 (or whatever)?

A simple tagged format like:
CTS: Active
RTS: Inactive
DTR: Active
DSR: Inactive
DCD: Inactive
RX Buffer: 0
TX Buffer: 0

Sure would aid debugging serial problems.

_OR_ a serial entry that you _COULD_ keep open forever, and
inspect it as you pleased (Personally I prefer the previous idea).

Andrew E. Mileski
Linux Plug-and-Play Project