GL-MT3000 (MT7981) USB host reliability

Does anyone have any experience using the USB host functionality of an MT7981 device, especially the GL.iNet GL-MT3000?

I'm in the process of trying to set one up as a travel router, but using an external USB WLAN card for WWAN instead of Travelmate (larger antennas). The USB device (Alfa AWUS036AXML, MT7921u) works great on an Ubuntu 23.04 laptop, but when connected to a GL-MT3000 (latest git master as of tonight), it will:

Start up in "device not active" state when first plugged in. but if I click "Restart" it might connect (not reliably...)

Log starting from device plugin, including the restart attempts below:

Within a few minutes, a USB disconnect occurs and then things go south.

I'm not sure if this is a USB host driver bug, an OpenWRT-specific MT7921 driver bug, or power brownout (I'll be trying a powered USB hub if I can before leaving on vacation Saturday). Has anyone else used the USB host functionality of this device successfully?

The full system log is too big to add to this post, so:

OK, I think I solved this. A powered hub seems to fix the problem, so it looks like a 5v 3A power supply (the stock supply of this device) is on its own not powerful enough to feed a GL-MT3000 AND a USB WLAN adapter.

So if anyone else is using USB devices with a GL-MT3000, make sure that they have their own power, whether it be a powered hard drive or a powered hub.

As a side note, is there any way to reference a device by USB PID/VID (and even better, serial number) in /etc/config/wireless so that changing hub port doesn't create a new radio entry?

Just an FYI and since your post made me curious...

I've got a TP-Link UE300 1Gbe USB adapter, so I plugged it into my USB power meter and saw it hit 0.80 W when booting, then stabilized around 0.73-74 W regardless of traffic (I did a big download over it, then let it idle for a while). This was on a laptop with power budget to burn.

Specs for your Alfa wireless adapter claim 2.7 W (0.54 A at 5v), so I can definitely see it pushing the poor little wall wart over its limit. (Found it here .)

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I would have thought that the GL-MT3000 would have more than 0.5A of margin to support its USB host port, but apparently not!

(I found it odd that the device and power supply have the exact same current spec, which implies no budget whatsoever for any USB peripheral - I'm guessing there is SOME budget but apparently not much!)

I've got a USB power meter somewhere but at the moment, it's hiding and I am trying to pack for a trip and get this working at the same time... I made the decision to get a new travel router to support VPN connections back to North America a bit later than I should have.

I have routers that are only capable of 250-350ma of power output. It wouldn't be surprising if they chose a 5v regulator in that range given that 5v 3a is not a lot to work with after powering an SoC, PA, and fan for just for basic functions.

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