Re: gpm/serial bug?

Theodore Y. Ts'o (
Sat, 16 Nov 1996 12:57:48 -0500

Date: Sat, 16 Nov 1996 00:40:35 -0500 (EST)
From: Tyson D Sawyer <>

I just spent too many hours figuring out that gpm was running and
shouldn't have been. I had a serial device attached to /dev/cua0
on a headless, sort of embedded, Linux PC. A short time after
starting the program that controls the device on the serial port
the the kernel would start thinking that bogus data was being typed
on the console.

This isn't a kernel problem; this isn't even a gpm bug. GPM is a
program which listens to mouse events (coming from /dev/cua0, in your
case, because that's how it was started in your /etc/rc scripts) and
provides cut and paste functionality to the console. Apparently your
devices was emitting characters which were getting interpreted as mouse
motions and mouse clicks, which was causing gpm to perform "cut and
paste" functions.

That's how come you were getting bogus data that was appearing to be
typed on the console --- that's what cut and paste is all about.

This was a strictly a user configuration error, no more and no less.
You shouldn't be running gpm on a serial port unless you have a serial
mouse hooked up to that serial port.

- Ted