Re: kern/57965: urtwn(4) command queue can overflow and deadlock

[Taylor R Campbell <riastradh%NetBSD.org@localhost>]

> Date: Thu, 29 Feb 2024 13:05:09 +0100
> From: Ramiro Aceves <ea1abz%gmail.com@localhost>
> 
> My RaspberryPi Zero W is using now the urtwn driver with a USB WIFI
> adaptor because of bwfm driver does not function well. I made a
> service that checks www.google.com and reboots the system if there is
> no ping,  checking 3 times during  5 min intervals.
> 
> With urtwn, network worked fine but router automatic changing channels
> leaded to complete network loss, needing reboot.

Can you share the output of these commands when it fails, before you
reboot?

ifconfig urtwn0
wpa_cli status
dhcpcd -U urtwn0

The symptom in this PR is that the commands will actually just hang in
tstile or mutex, and examination with `ps' (either ps(1), or in
crash(8) or ddb(4)) will show that some process is waiting for
urtwntsk; the stack trace in crash/ddb will show it is waiting in
urtwn_stop.

If your symptom does match, there's a good chance this will resolve
it.

If your symptom doesn't match, can you file a new PR for it?