Kernel panic with two dongles plugged in USB 3.0 about 88x2bu HOT 4 CLOSED

I understand why the kernel panicked... I panicked while reading your post!

That is an interesting setup. Can I get you step back and explain the big picture to me. What is it that you are trying to accomplish? Repeater?

Some other info that could enhance this conversation:

Are you using hostapd to set up the AP?

Is the Centos a 64 bit variety?

I see that you are using rtw_vht_enable=2. Are you aware that this does good things for AP mode but terrible things for other modes?

My opinion: You might get a Pi going with two USB WiFi adapters in different modes if the adapters were based on different chipsets and used different drivers. Well, I do that here. Actually I have as many as 4 usb wifi adapters on one system at time but all adapters have different chipsets and use different drivers.

from 88x2bu.

It is something of a repeater that we are making as a part of one of products (not in the sense of any typical Linux bridging though). We are actually using two different dongle chipsets an 8822bu and an 8811cu. The problem being the 8811cu isn’t as performant so we are working on getting two of the 8822bu devices working and any insights would be great.

We are not using hostapd and went with NetworkManager as our application calls out and makes various commands to build out and set up the various things needed for the network and integrating with one tool was easier at the time then integrating with many tools. This is slowly, but surely changing as we build out richer feature sets.

The Centos version is of the 64 but variety.

I have actually been experimenting with vht set to 2 for a little bit today. Any insight into what problems that introduces to the other modes?

from 88x2bu.

My thoughts:

$ iw list

The above will show the following statement near the bottom:

"interface combinations are not supported"

That means the driver will not support more than one type of interface at the same time... and that is with one adapter.

What you are doing is going way beyond that by using two of same type of adapters. This driver is not built to support more than one adapter at the same time as far as I know. I've never even thought to try it but in thinking about it, the system is not built to support that... in any OS as far as I know.

My recommendation, if you are looking for another adapter that can support 867 Mb/s, is to get another adapter with that capability but uses a different chipset... the rtl8812au. I have a very good driver for the 8812au right here on this site:

https://github.com/morrownr

You can load multiple drivers supporting multiple USB adapters but the adapters need to have different chipsets. I do it here with up to 4.

Caution: Only use ( rtw_vht_enable=2 ) for the driver that is going into AP mode.

The adapters based on the MT7612u chipset have in-kernel support these days but I don't remember when that support first appeared. It is capable of 867 Mb/s.

Hopefully some of what I said helps.

Nick

from 88x2bu.

Good luck with your use case. If you need to reopen another issue, you are welcome to do so.

from 88x2bu.