Re: USB-serial adapter suggestions needed

On Sun, Dec 24, 2023 at 01:21:40AM +0000, Marcin Cieslak wrote:
> On Sat, 23 Dec 2023, bob prohaska wrote:
> 
> > On Sun, Dec 24, 2023 at 12:47:56AM +0000, Marcin Cieslak wrote:
> > > On Sat, 23 Dec 2023, bob prohaska wrote:
> > > 
> > > > What are the best-supported usb-serial adapters for use with FreeBSD on arm systems?
> > > 
> > > I am using uchcom(4)-based CH340, the reason I have it is selectable 3.3V/5V level.
> > > I don't have a Raspberry but I use it for other arm boards.
> > > 
> > > Not sure it is "better" than, say ft232
> > 
> > Have you run into any oddities using the ch340? Noise on the lines,
> > dropped connections, irreproducible behavior?
> 
> Only this https://lists.freebsd.org/archives/freebsd-arm/2023-March/002422.html -
> responding to your post about halted boot - but this is an EFI console problem.
> 
> > Thanks for writing & confirming ch340 is an option!
> 
> Are you still troubleshooting your broken tip connections?

I'm still seeing tip sessions and the associated ssh connections drop,
but am no closer to understanding what's wrong. There does seem to be
a (somewhat imperfect) association between dropped tip sessions and
the use of FTDI-232 usb-serial adapters, but the sample is too small
(7 units) and too erratic (mix of Pi2, Pi3 & Pi4 hosts) to be sure of
anything. 

That's surprising given the Pl2303's rather poor repute and the ft232's
sterling reputation, but far from decisive. In my initial testing a few
years ago it seemed the reputations of the pl2303 and ft232 were more or
less deserved; the pl2303 seemed a little flakier and the ft232. Now that
situation seems to be reversed. 

If there's another usb-serial bridge option which open-source programmers 
prefer it seems wise to adopt it. That's what I'm fishing for. 

Thanks for reading!

bob prohaska