Red Hat Bugzilla – Bug 145339
agetty locks serial console access
Last modified: 2007-11-30 17:07:06 EST
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User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET
Description of problem:
I connect to the serial port of my Linux machine via a cisco 2500
When I login and I press Ctrl+A and then Ctrl+S, the serial console
gets locked and there is no way to recover it.
With mgetty this does not happen.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.Login to machine through serial console
2.Press Ctrl+A and then Ctrl+S
Actual Results: Console no longer responds
Expected Results: Nothing should happen
This is the configuration line for the serial console:
co:2345:respawn:/sbin/agetty -L ttyS0 115200 vt100
I have also tried without the -L option.
With this configuration on mgetty, the problem does not appear-:
co:2345:respawn:/sbin/mgetty -r -s 115200 -p "Login: " ttyS0
'Ctrl-S' is the signal to the system to stop sending new data to the
Pressing 'Ctrl-Q' should "unfreeze" things.
This is normal and expected behaviour. I don't know why it doesn't
work with mgetty - that sounds like the real bug.
You are right. Ctrl-Q unfreezes the console. This was probably the
only combination of keys I did not try.
Are these control codes documented anywhere?Ã§