Re: port-i386/57662: StarTech ICUSB23208FD 8-Port USB-to-Serial Adapter Hub fails on Alix with NetBSD/i386 9.3

[Alexander Schreiber <als%thangorodrim.ch@localhost>]

On Sun, Oct 15, 2023 at 09:35:02PM +0000, Manuel Bouyer wrote:
> The following reply was made to PR port-i386/57662; it has been noted by GNATS.
> 
> From: Manuel Bouyer <bouyer%antioche.eu.org@localhost>
> To: gnats-bugs%netbsd.org@localhost
> Cc: port-i386-maintainer%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
>         netbsd-bugs%netbsd.org@localhost
> Subject: Re: port-i386/57662: StarTech ICUSB23208FD 8-Port USB-to-Serial
>  Adapter Hub fails on Alix with NetBSD/i386 9.3
> Date: Sun, 15 Oct 2023 23:31:07 +0200
> 
>  On Sun, Oct 15, 2023 at 08:45:01PM +0000, als%thangorodrim.ch@localhost wrote:
>  > [...]
>  > 
>  > I can then connect via "cu -l /dev/ttyU0 -s 115200" to an attached device,
>  > and disconnect via the "~." sequence. This works 1-2 times and then any further attempts to do so only yield "cu: link down" and then cu exiting.
>  > 
>  
>  I've seen this with other USB a non-USB serial ports.
>  Usually this is because the serial port is not completely closed (cu usually
>  has 2 processes running, one may be left over when exiting).
>  killing the leftover processes allows a new cu session to start

The fact that:
 - upon device plug-in, I get a "fatal breakpoint trap in supervisor mode"
 - upon removing, waiting a few min and plugging the device back
   in I get "uhub1: autoconfiguration error: device problem, disabling port 1"
tells me that this might not be the problem.

I suspect either some state corruption in the kernel driver or (actually
more likely) incorrect handling of device quirks (quirk being a polite
way of saying the device does something broken). This might be a combination
of USB host issues (it appears to work fine on a different h/w with
amd64) and NetBSD not having as much developer time to deal with devices
behaving oddly (it works with Linux on the same h/w).

-- 
"Opportunity is missed by most people because it is dressed in overalls and
 looks like work."                                      -- Thomas A. Edison