Re: USB-serial adapter suggestions needed

On Jan 7, 2024, at 08:48, Mark Millard <[email protected]> wrote:

> On Jan 6, 2024, at 19:00, Mark Millard <[email protected]> wrote:
>> 
>>> On Jan 6, 2024, at 18:36, bob prohaska <[email protected]> wrote:
>>> 
>>> On Sat, Jan 06, 2024 at 11:44:49PM +0000, Marcin Cieslak wrote:
>>>>> On Fri, 5 Jan 2024, Mark Millard wrote:
>>>>> 
>>>>> 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.
>>>> 
>>>> I second this. There is way too much text in this conversation
>>>> and not enough data. It also does not help if every system is somewhat
>>>> different.
>>> 
>>> Unfortunately, the systems simply are different. Four Pi2
>> 
>> Please differentiate RPi2B v1.1 (armv7) from v1.2 (aarch64).
> 
> I meant that to be a general request to never reference just
> RPi2B. The v1.1 vs. v1.2 was an unfortunate marketing naming
> for the armv7 vs. aarch64 change that ends up needing such
> extra text to give the proper context.
> 
>> I suggest armv7 use the snapshot armv7’s config.txt as its
>> config.txt prefix.

Now that I have my normal internet access back, FYI:

# dd if=FreeBSD-15.0-CURRENT-arm-armv7-GENERICSD-20240104-8bf0882e186e-267378img of=/dev/da0 bs=1m conv=fsync,sync status=progress
  5205131264 bytes (5205 MB, 4964 MiB) transferred 18.064s, 288 MB/s
5120+0 records in
5120+0 records out
5368709120 bytes transferred in 18.680162 secs (287401640 bytes/sec)

# mount -onoatime -tmsdosfs /dev/da0s1 /mnt

# more /mnt/config.txt
init_uart_clock=3000000
enable_uart=1
kernel=u-boot.bin
kernel7=u-boot.bin
dtoverlay=mmc


>>> , two Pi3,
>>> one Pi4. I'll try to make the config.txt files on the Pi3s match
>>> better when the present experiment is complete. The interconnection
>>> of hosts is unique and, apparently, unusual. Not all of that is
>>> relevant, but exatctly what part isn't yet obvious.
>>> 
>>>> 
>>>> I have skimmed the peripherial documentation for one of the Broadcom
>>>> chips (I think the one from Raspberry Pi 3) and it says that
>>>> the speed of the mini uart depends on the CPU clock frequency.
>>>> 
>>>> I could imagine a situation when mini uart speed changes during
>>>> downlocking the CPU.  There was suggestion to not use mini uart.
>>>> Use the port where the frequency is not changing with the weather.
>>>> 
>>> 
>>> Agreed, and I changed config.txt to set
>>> dtoverly=disable-bt
>>> on www.zefox.org (the console host) to force use of the PL011.
>>> It didn't help detectably.
>>> 
>>>> I don't know how smart is the power management with powerd, but
>>>> I could also imagine shutting down peripherials or stopping the UART
>>>> clock as a potential power saving feature, so here you are.
>>> 
>>> No sign of that, but Mark posited that powerd might be causing
>>> trouble with the terminal server (pelorus in this test). That
>>> looks like a possibility. At the moment pelorus is without
>>> powerd and it's holding a serial connection to www.zefox.org.
>>> 
>>> Meanwhile www.zefox.org is running powerd and buildworld
>>> while being a terminal server to a Pi4 named nemesis.zefox.com
>>> That connection has dropped twice so far today.
>> 
>> Interesting. You have not reported on nemesis.zefox.com ‘s config.txt
>> content or powerd status. Also, which type of RPi* ?
> 
> If the chart you referenced is right for the issue: RPi4B. (Other
> details about turned out to be in accurate at the time as I
> remember, so the cross check seems appropriate.) If so, that
> still leaves the status of powerd and the config.txt content
> to publicly document.
> 
> Also, as I understand the reports, a system running both tip and
> powerd ends up dropping the serial console connection at times.
> A system running tip but not powerd does not drop the connection.
> 
> However, it might be that some form of test of a RPi* running
> powerd and just tip and not ssh might be useful. Similarly for
> a RPi* running powerd and just ssh, not tip. I'd expect that
> the tip+powerd-ssh case (so no ssh) to fail and the
> ssh+powerd-tip case (so: no tip) to not fail.



===
Mark Millard
marklmi at yahoo.com