Re: USB-serial adapter suggestions needed

On Fri, Jan 05, 2024 at 07:26:16PM -0800, Mark Millard wrote:
> 
> I'd next try having powerd disabled only on the terminal server
> pelorus and then checking for getting a failure.
> 

I started powerd manually on www.zefox.org using
powerd -a adp (which I think is the default)
last night. The machine's console connection lasted all night.
Previously powerd was started via /etc/rc.conf. Might that be
somewhat different?

However, early in the evening I accidentally crashed the RPiOS
workstation, forcing me to re-establish all the console sessions.
When the connection to www.zefox.org came back up it was prefaced
by the usual non-printable gibberish. That session is still up
as I write this. Could the gibberish be the result of getty
activity on www.zefox.org as it establishes the connection from
pelorus (the terminal server)? Part of baudrate negotiations, 
maybe? 

The overnight test was unloaded. Now www.zefox.org has been 
updated: Updating 499e84e16f56..aa1223ac3afc
with a -j4 build/install cycle running with 3.5 GB swap
divided between two USB mechanical hard disks.  

> Last I would try instead having www.zefox.org <http://www.zefox.org/> be the only one
> of the two with powerd disabled.
>
That test will come next, in a couple of days.
 
> I expect that having powerd disabled just on pelorus will prove
> sufficient and that having powerd disabled just on www.zefox.org <http://www.zefox.org/>
> will not prove sufficient.
>
 
So the difficulty is on the ethernet-usb-serial side? 
I was thinking it's on the serial-console side, maybe
an inadvertent escape sequence from baud mismatch.

> I also request to again list the exact content of the two
> config.txt files --and again every time they are changed during
> this investigation.
> 

On pelorus, the terminal server, config.txt contains:
bob@pelorus:~ % more /boot/efi/config.txt
[all]
arm_64bit=1
dtparam=audio=on,i2c_arm=on,spi=on
dtoverlay=mmc
dtoverlay=disable-bt
device_tree_address=0x4000
kernel=u-boot.bin

[pi4]
hdmi_safe=1
armstub=armstub8-gic.bin

On www.zefox.org, the console client, config.txt contains
bob@www:~ % more /boot/msdos/config.txt
arm_64bit=1
dtoverlay=disable-bt
init_uart_clock=3000000
enable_uart=1
kernel=u-boot.bin
kernel7=u-boot.bin
dtoverlay=mmc
force_mac_address=b8:27:eb:71:46:4f

I'll admit to some uncertainty where 
init_uart_clock=3000000
and 
kernel7=u-boot.bin
came from. The latter seems harmless, but I'm
not so sure about the former. 

> 
> You also have the option of fixed-rate clocking that is faster
> than FreeBSD default. This can be controlled from config.txt .

As a last resort, yes. Still, I'd like to minimize power use
to the extent possible. Powerd seems optimized for laptops.
Maybe it isn't the right tool for mains-powered, lightly
loaded servers which occasionally see saturation loads.

Thanks for writing!

bob prohaska