23.05.3 iwinfo scan disconnects AP
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@crispyoz i tested on two omega2pro and an omega2s+ (running 23.05.3) on our custom pcb. Both disconnects on laptop and pc. I will now get another old pc and check again with this one.
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@DocHardinger Can you set option disassoc_low_ack '0' on your AP and see if it makes any difference. I need it on my sta when connecting to one of Unifi APs.
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Yes i already thought about this but makes no difference
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@crispyoz ok now tested with an old surface book 2, this one keeps the connection. My gaming pc and a new Dell Precision Laptop still keeps disconnecting.
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@DocHardinger I think I have a clue. I managed to reliably reproduce the issue on a Lenovo P15s notebook running windoze 10. It will reliably disconnect if I run iw ra0 scan in a loop on OpenWrt 23. So I ran Wireshark to check for lost packets, acks etc, nothing notable to report. However I did notice the Wifi signal strength kept dropping and then the SSID disappears. If I set the saved network to autoconnect, it reconnects fine. But as the loop runs it disconnects again and then reconnects etc. I put my iPhone and Android 11 devices next to the P15s at the same so they are the same distance from the Omage2p and neither of them disconnect when the windoze device disconnects.
This Lenovo P15s can dual boot either windoze 10 or Ubuntu 24.10, so this time I booted into Ubuntu and ran the same test, it doesn't disconnect. So the problem is isolated to windoze.
I ran LinSSID on Ubuntu and it does not detect any notable drop in signal strength, so I rebooted in windoze and ran Acrylic WiFi Analyser, it shows a short-lived drop in signal strength when I'm running iw ra0 scan in a loop.
My working hypothesis is that windoze is aggressively monitoring connectivity and the faster the machine the more likely it is to disconnect, but slower devices like iphones, android phones and old Surface devices are simply not noticing the short lived signal drop.
OpenWrt 22 uses iw v5.16 OpenWrt 23 uses iw v5.19, so I wondered if the newer iw is doing something different. Looking at the code the changes are minimal, so I installed iw v5.16 on OpenWrt 23 but the issue persists.
Both 22 and 23 use the same mt76 firmware release, so I'm looking at the driver code for some hints.
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@crispyoz For now i will ignore this behavior because our customers only use mobile phone to interact with the omega, and this works so far. Anyway not so good to not know whats going on there...
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@DocHardinger I believe I identified the cause yesterday, once I have finished testing I'll update the forum.
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@crispyoz any news?
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@DocHardinger I'm currently travelling so haven't completed my testing since I don't carry a Windoze machine with me. However what I found thus far is that if I slow down iwinfo by ~200ms each probe, the windows machine does not disconnect.
The question I want to answer, is whether this tiny delay simply reduces the load on the Omega2p so it can respond to the network requests in a more timely manner. If this is the case, then my earlier hypothesis that windoze is simply less tolerant of response time variations than lesser systems, would appear to be true.
But I am not yet prepared to make that conclusion until I have done more testing, but if this were the case then we just create a patch to add this functionality.
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@crispyoz ok, i discovered another strange behavior. When connecting to an ShellyBluetooth Dongle AP the omega keeps disconnecting/connecting. I need to run a script which continuesly ping the AP to keep the connection. With other hardware the connection to the shelly is no problem. So it looks like the omega is doing something different.