23.05-rc2 and radios on Belkin RT3200

Unlike another poster, my upgrade from 22.03.5 UBI went mostly well in that the radios (including additional SSIDs on VLANs) came up okay. It is just that connected wireless devices won't show up in status nor will either of the radios do a wireless scan.

Any suggestions for what to look at?

(Edited to add that the STAs will show up using the iw command, just not on the GUI)

root@BelkinRT3200:~# cat /etc/config/wireless

config wifi-device 'radio0'
        option type 'mac80211'
        option path 'platform/18000000.wmac'
        option country 'US'
        option band '2g'
        option htmode 'HT20'
        option channel '11'
        option cell_density '0'

config wifi-iface 'default_radio0'
        option device 'radio0'
        option network 'lan'
        option mode 'ap'
        option ssid 'lexluthor24'
        option encryption 'psk2'
        option key '*****'

config wifi-device 'radio1'
        option type 'mac80211'
        option path '1a143000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0'
        option country 'US'
        option band '5g'
        option cell_density '0'
        option channel '52'
        option he_su_beamformee '1'
        option he_bss_color '8'
        option htmode 'VHT80'

config wifi-iface 'default_radio1'
        option device 'radio1'
        option network 'lan'
        option mode 'ap'
        option ssid 'lexluthor50'
        option encryption 'psk2'
        option key '*****'

config wifi-iface 'wifinet2'
        option device 'radio0'
        option mode 'ap'
        option ssid 'Guest24'
        option encryption 'psk2'
        option key '*****'
        option network 'VLANGUEST'

config wifi-iface 'wifinet3'
        option device 'radio0'
        option mode 'ap'
        option ssid 'lexluthor-IoT'
        option encryption 'psk2'
        option key '*****'
        option network 'VLANIOT'

So I had firmware-selector build me a custom UBI image with some packages that I would have installed anyway and flashed that image. Now the 2.4GHz radio works perfectly including showing associated stations and doing a scan. The 5GHz radio, on the other hand, shows enabled on the Wireless page but isn't even broadcasting its SSID.

The relevant section from the output of hwinfo for radio1 is:

05: PCI 100.0: 0002 Unclassified device
[Created at pci.386]
Unique ID: B9V1.WgpudJEozJ1
Parent ID: qLht.T0GRoeMldUD
SysFS ID: /devices/platform/1a143000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0
SysFS BusID: 0000:01:00.0
Hardware Class: unknown
Model: "MEDIATEK Unclassified device"
Vendor: pci 0x14c3 "MEDIATEK Corp."
Device: pci 0x7915
SubVendor: pci 0x14c3 "MEDIATEK Corp."
SubDevice: pci 0x7915
Driver: "mt7915e"
Driver Modules: "mt7915e"
Device File: wl1-ap0
Memory Range: 0x20000000-0x200fffff (ro,non-prefetchable)
Memory Range: 0x20100000-0x20103fff (ro,non-prefetchable)
Memory Range: 0x20104000-0x20104fff (ro,non-prefetchable)
IRQ: 152 (29115 events)
HW Address: e8:9f:80:ec:d8:b2
Permanent HW Address: e8:9f:80:ec:d8:b2
Link detected: yes
Module Alias: "pci:v000014C3d00007915sv000014C3sd00007915bc00sc02i80"
Config Status: cfg=new, avail=yes, need=no, active=unknown
Attached to: #6 (PCI bridge)

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Assuming you already tried to fix the configuration issue: I would drop your configuration, do an OpenWrt factory reset and rebuild your configuration from scratch.

Either from Luci or command line:

This message is sent via OpenWrt 23.05-Snapshot on E8450-UBI, some weeks after RC2. It should not be a code issue but a configuration issue.

After re-creating the config from scratch, everything seems to be working except that the 5GHz radio still won't do a scan. Is it not supposed to? (I can connect to the configured SSID though)

The scan button in Luci wireless menu is for joining your device as a client station to an already existing other SSID. This is what you want to do?

That is how I use it on my travel router. Here I am merely trying to do a wireless survey.

Since my last post, I have discovered that scan works if no AP is configured on this radio but shows no SSIDs once an AP is configured. Scan works on the 2.4GHz radio even when APs are configured.

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I've observed a similar behavior on the Xiaomi AX3200 (same radios as RT3200), but in a different feature.

Basically the LuCI option "Status -> Channel Analysis" does not work for the 5Ghz radio either (it only shows its own channel), which is a defect:

The root cause is probably be the same. This limitation seems to be specific for the MediaTek MT7915E, since I have another access point with MediaTek MT76x2e which works fine as expected:

Good to know.

I tried using the iw scan command in the CLI and got

command failed: Resource busy (-16)

And Channel Analysis doesn't even show itself in the diagram

I've just disabled the 5Ghz radio on the Xiaomi AX3200 and the "Channel Analysis" then works fine. Exactly the same behavior you reported.

It is either a bug or a limitation of this radio.

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Fortunately, I don't need it to work but was curious as to what was happening.

Watching for other networks is a different menu item: Status -> Channel Analysis.

Mine does work, Channel Analysis on 2.4 GHz MT7622 integrated radio and on 5 GHz MT7915 radio. 23.05-snapshot, some weeks after RC2. E8450-UBI.

I learned that from @dsouza

I will wait for rc3 or even stable rather than trying snapshot

Channel Analysis works on my E8450 on 23.05-snapshot. Not much newer than RC2.

It’s not master snapshot, only 23.05-snapshot. More or less a preview of the coming RC3.

You are correct:

Well, I don't think the above statement is correct that Channel Analysis requires a second 5Ghz radio (but it is my opinion only).

For example, one of my AP is a small/low-end TP-Link RE305, and this is the one that Status -> Channel Analysis is working fine.

I also remember an TP-Link Archer C6v3 also having the Channel Analysis working fine.

Both TP-Link RE305 and Archer C6v3 are much inferior to the Xiaomi AX3200 (which Channel Analysis is not working).

It depends, on:

  • the hardware
    • its firmware
    • the driver
  • the region (FCC vs ETSI vs MKK vs China, etc.) and its regulatory requirements
  • the tuned channel
    scanning while being tuned to a non-DFS channel is easier, than while being tuned to a DFS channel (where the chip has to scan for radar events constantly, this makes leaving the channel intermittently for scanning harder (depending on the exact regional regulatory requirements impossible).

There simply is no generic answer to this question.
If it works for you, great.
If it doesn't, that may very well be o.k. (working as required). To tell if it could work, is very hard without a deep dive into the driver code and the (usually unobtainable) hardware specifications - and impossible without talking about where the user is located (due to the local regulatory requirements).

That is why quite a few high-end routers have a dedicated radio exclusively used to search for DFS events, constantly scanning the ether to have an alternative free channel (without an active radar signal) on retainer.

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Is this functionality of DFS scanning via a separate radio supported by OpenWrt on any router which can be bought on Amazon now?

There are devices that have been designed with that in mind (e.g. wrt3200acm/ wrt32x[0]), but even the vendor never actually made use of that as such in their proprietary firmware (probably they didn't get it working sufficiently well, but they did add a third radio exclusively meant for this purpose, in an environment where fractions of a cent count). No device using OpenWrt can do that at this point, as the drivers/ firmware won't allow omitting the DFS scanning on the primary device anyways (so there wouldn't be much of a gain compared to just doing it once, on the main radio); locked down proprietary firmware that don't allow (easy-) tampering would have more freedoms in this regard.

Some enterprise APs (with their proprietary firmware) probably have this features, but I don't have a specimen at hand.

[0] the Xiaomi Mi AIoT Router AX3600 and -AX9000 also come with a similar third radio, albeit with a different purpose in mind (second 2.4 GHz network for Xiaomi's IoT ecosystem, the radio itself is 1x1 802.11ac dual-band though)

I'm wondering if the patch below would be also applicable to this case:

[PATCH] mac80211: fix MT7620 Wi-Fi channel scanning function


it should work, can you show
iw phy0 info
iw phy1 info
i do not know if your 5ghz is phy0 or phy1.