It took me some time, but now I have OpenBSD 7.7 on an Acer laptop
with iwm. I will send you iwm0.pcap off-list in a few minutes.
Apparently it's channel 48 that I need now.
Note, however, that this device has absolutely no problems connecting
to the same network, so maybe the results are irrelevant.
I still can't reproduce the bwfm connection problems reliably. They
occur often, but are seemingly chaotic. Sometimes ifconfig says
"status: active", but ping 192.168.0.1 either reports 100% packet loss
with no error messages or prints "Can't assign requested address"
repeatedly. Sometimes ifconfig says "status: no network" and ping says
"Network is down". Sometimes ping says "Can't assign requested
address" a few times and then suddenly packets start being received.
What I can observe reliably is that when there *is* connection, packet
loss measured with ping is around 50%. This I have observed reliably.
It doesn't seem to matter whether I use 5GHz or 2.4GHz. Taking off the
case and placing the computer half a meter away from the router
doesn't help, still about 50% loss. Not using bwfm, using an USB
urtwn0 adapter: still about 50% loss. OpenBSD on another computer
(that Acer with iwm): 0% loss, even from a different room. Linux on
the same Raspberry Pi: 0% loss from a different room. But NetBSD on an
equivalent Raspberry Pi: 50% loss. I don't know how to interpret it.
Another thing that I have noticed (it probably isn't relevant either,
but might indicate some other problem): on the Acer laptop, if I have
no hostname.iwm0 and enter `doas ifconfig iwm0 up` followed by `doas
ifconfig iwm0 mediaopt monitor`, the system almost always crashes
immediately. The white on blue error message is something like
`uvm_fault(0xffffffff82b4aaa0, 0x0, 0, 1) -> e`. Only once didn't it
crash and printed `ifconfig: mediaopt: SIOCGIFXFLAGS: Device not
configured` instead. Also, if I have no hostname.iwm0 and enter `doas
ifconfig iwm0 debug`, then `doas ifconfig iwm0 mediaopt monitor`, then
`doas ifconfig iwm0 up`, I immediately end up in the kernel debugger
(I'll send a screen photo off-list as well).
Best regards
Stanislav Syekirin
On Mi, 10 Apr 2024 08:48:45 +0200
Stefan Sperling <s...@stsp.name> wrote:
ifconfig iwm0 mediaopt monitor
ifconfig iwm0 chan 112 # assuming the AP has not moved channels
ifconfig iwm0 up
tcpdump -n -i iwm0 -y IEEE802_11_RADIO -s 4096 -w /tmp/iwm0.pcap
Now attempt the failing association, then cancel tcpdump with Ctrl-C
and send me the /tmp/iwm0.pcap file offlist.
