Re: USB-serial adapter suggestions needed

On Jan 12, 2024, at 11:18, bob prohaska <fbsd@www.zefox.net> wrote:

> On Fri, Jan 12, 2024 at 10:34:11AM -0800, Mark Millard wrote:
>> 
>> If you did not specify the signal explicitly, you tried:
>> 
>>     15    SIGTERM          terminate process    software termination signal
>> 
>> (I'm not claiming all those "terminate process" signals are
>> likely to be involved. But SIGTERM is need not be involved
>> at all.)
>> 
>>> Both the ssh connection from workstation to terminal
>>> server and the su to root needed to run tip survive.
>>> 
>>> I should apologize for not testing this sooner, it
>>> was a very easy experiment. If you think of useful
>>> variations please indicate them.
>> 
>> See above, in particular SIGHUP .
>> 
> 
> Just tried SIGHUP several times. The ssh connection didn't
> disconnect. There were also no reports about overriding stale
> locks. 
> 
> Using SIGKILL reported:
> 
> login: Killed
>             root@nemesis:/home/bob # 
> root@nemesis:/home/bob # tip ucom
> Stale lock on cuaU0 PID=45604... overriding.
> connected
> 
> 
> FreeBSD/arm (ns2.zefox.net) (ttyu0)
> but the ssh session and su survived.
> 
> Finally, I tried SIGSTOP. Again, ssh and su stayed up, but
> restarting tip reported:
> all ports busy
> Power-cycling the usb-serial adpter with usbconfig
> isn't able to free the port. That's new-to-me behavior.
> Deleting the /dev/cuaU0-related files didn't help.
> 
> Not sure what to make of this, except that ssh survives
> exit of tip, graceful or not.  

Remember:

Jan 10 14:29:48 nemesis kernel: ucom_close: tp=0xffffa00001979800
Jan 10 14:29:48 nemesis kernel: ucom_shutdown: 
Jan 10 14:29:48 nemesis kernel: ucom_dtr: onoff = 0
Jan 10 14:29:48 nemesis kernel: ucom_line_state: on=0x00, off=0x01
Jan 10 14:29:48 nemesis kernel: ucom_rts: onoff = 1
Jan 10 14:29:48 nemesis kernel: ucom_line_state: on=0x02, off=0x00
Jan 10 14:29:48 nemesis kernel: ucom_cfg_close: 
Jan 10 15:04:07 nemesis su[35181]: bob to root on /dev/pts/4

(and what was somewhat before and somewhat after)?

What were those messages like (if any) for each of the types of kills?

===
Mark Millard
marklmi at yahoo.com