[BRLTTY] brltty hangs after startup
Sébastien Hinderer
Sebastien.Hinderer at ens-lyon.org
Fri Apr 8 03:12:23 EDT 2011
Hi,
Dave Mielke (2011/04/08 00:18 -0400):
> If restarting brltty makes it work correctly then that'd seem to eliminate the
> possibility of tere being a flow control and/or parity problem.
Indeed.
> Is there an initial handshake during driver startup, involving data being sent
> from the computer to the device, which must take place? If so, would I be
> correct in assuming that this has actually occurred correctly, implying that
> data transfer from the computer to the device at least started out
> working?
I'm not sure about the initial handshake, but I'm sure your assumption
is correct, since, before hanging, brltty works perfectly fine: text is
displayed on the braille display and it is possible to use screen
reading commands.
> One possibility, especially being as you're using what's effectively a serial
> port, is that the kernel is doing some probing (perhaps for a mouse) at system
> startup, and that this is interfering with the communication between brltty and
> the device.
Actually, the interference seems to be cased by the NetworkManager
daemon.
Indeed, if it is disabled, the system boots up correctly and brltty does
not hang. I guess I'll have to investigate further on how NetworkManager
should be configured so that it can be enabled without disturbing
brltty.
Sébastien.
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