Bug#760916: brltty interferes with getty autostart

[Samuel Thibault]

Dave Mielke, le Mon 29 Dec 2014 12:04:19 -0500, a écrit :
> We could open it on demand rather than immediately?

On which demand?

Whatever the timing, there is a risk that systemd-logind gets slow for
some reason, and not manage to start getty before brltty opening it.

One way could be for brltty to quickly check from /dev/tty1 with
VT_GETSTATE whether some process is actually running on the new VT,
before opening /dev/tty0.  That will always succeed in normal operation,
it will fail when systemd-logind hasn't started getty on the VT yet,
thus preventing brltty from opening it.  Another scenario to consider
is people who could be emitting data to some VT through e.g. a cronjob.
An additional check that brltty could do after VT_GETSTATE would be
checking whether /dev/vcsa is a blank screen.  In that case, there is
indeed really nothing to do with the VT.

Samuel