Christos Zoulas <christos@astron.com> typed:
: I mis-read the previous message. It seems that before it was failing to
: do the F_SETOWN so it defaulted to polling instead of using SIGIO. Now
: it is using SIGIO and failing for some reason. There are no warning messages
: now?

It installs the signal handler (*) OK, however there are no SIGIO
signals (xf86SIGIO() is never called).  According to lsof, /dev/mouse sits
on 6 chars in - which is the starting point with a working mouse so maybe
that's an initialisation response.

(*) xsrc/xfree/xc/programs/Xserver/hw/xfree86/os-support/shared/sigio.c

JIC, /dev/mouse is
    com0 at acpi0 (PNP0501-1)
    com0: io 0x3f8-0x3ff irq 4
    com0: ns16550a, working fifo

Regards,
Geoff