(HOT!) Report on the rtl8852au and rtl8832au chipsets and driver

[morrownr]

chipsets- rtl8852au and rtl8832au - AX1800 - USB 3

The rtl8852au and rtl8832au chipsets were the first USB WiFi 6 (AX) capable chipsets from Realtek. Unfortunately, Realtek decided to support these chipsets with an out-of-kernel driver instead of doing the right thing and providing a mac80211 technology in-kernel driver. The Linux driver (v1.15.0.1) was found on a CD provided with a cheap adapter I bought solely for the purpose of helping the community. I also found this version of the driver located in a couple of Github repos and it appears this version is the only version released by Realtek. I, and two others, tried to get this driver up to speed so as to release it to the public along with the other Realtek drivers located at this site. The work did not go well and the results were not good. Many features simply were not working. Power saving did not work. DFS channels did not work in AP mode. USB mode control was problematic. WPA3 did not work in any mode. We saw problems in basic client mode that we could not explain. v1.15.0.1 is a VERY BAD driver. It was decided to not make the driver public and to warn Linux users to not buy adapters based on the 8852au and 8832au chipsets.

Available information indicates that Realtek terminated production of the 8852au and 8832au chipsets during 2021. There is no information that I am aware of that indicates why the production run was so short. It does raise red flags in that there may have been issues that were problematic and could not be resolved in software.

Recommendation: AVOID adapters based on the 8852au and 8832au chipsets. You will be disappointed.

[codebling]

Thanks for the update! I don't see too many other AX USB drivers. I found 2 NGFF 6E cards at a reasonable price, the MT7921K and the AX210. Both seem to be supported in main kernel. I will try those with a USB PCIe/NGFF bridge. Let me know if you find out of any other AX USB chipsets

[morrownr]

Hi @codebling

I am hearing that Realtek has already gone end of product with the 8852/32au. This really smells like there are silicone problems that can't be fixed with software in this chipset. Evidently a new 8852/32bu is near the start of production. I can actually see it mentioned in the Realtek code that I mentioned in the original post. I hate to keep talking about how bad that driver is but it is ridiculously bad.

I am hoping to see something from Mediatek about a mt7921u and/or mt7921ku soon. CES 2022 is going on this week. Maybe we will hear something. I can confirm that the mt7921 is supported in the kernel as Santa brought me a new laptop for XMas and it has a mt7921 chipset that fired right up with Ubuntu 21.10. No problems noted.

Would you mind posting links to the USB PCIe/NGFF bridge and two cards you mentioned?

Thanks

[codebling]

Two cards are here (Aliexpress). Adapter is something like the one here, though this is not specifically the one I have.

[morrownr]

Two cards are here (Aliexpress). Adapter is something like the one here, though this is not specifically the one I have.

Talk to me about this setup. How are the antennas handled?

[codebling]

The cards have antenna IPEX connectors on them. I have some IPEX to SMA connectors and a bunch of antennas so the plan is to use those.
So they aren't really tied down. For a more permanent setup one might want to create an enclosure and affix the antenna to that. I haven't done very much experimentation with this setup, so far I have an LTE modem on one

[morrownr]

Ah, that leads to another question: Will the mt7921e or intel driver that is in the kernel drive this setup or do you need the as of yet non-existant mt7921u drive or the possibly never to be existant Intel usb driverr?

If the in-kernel driver that drives internal cards will drive driver this then wow, I can see a solution to a lot of problems.

[codebling]

I am a bit unfamiliar with the bridge tech but I think/hope it will use the PCI-e driver, but I'm not sure about this. I thought it would create a second PCI-e bus in the system but when I try with the one I have, I see the PCI-e card listed as a USB device (the bridge itself doesn't show up under lsusb or lspci), so I could be completely wrong about this. I'll try it when the cards get here.

[morrownr]

Let me know what you find out.

[codebling]

I received the AX210 but I'm still waiting on an NGFF adapter. I thought I had one lying around but apparently not. I'll report back with my findings

[morrownr]

Standing by...

[codebling]

@joshschmelzle thanks for the info. That's good! M.2 M key supports PCIe x4. That means an A+E -> M might work.

I currently have an LTE card working on a USB key so I know I'm not completely barking up the wrong tree. It feels like just a matter of cabling now.

[joshschmelzle]

Just a note that your LTE card is likely using USB not PCIe. Does the LTE card show up under lsusb or lspci?

[codebling]

It does show up under lsusb. But these adapters do seem to support mPCIe, like this mini-PCIe to USB3.0 Adapter (full product page).

The whole idea was to grab some cheap (Wifi6E as cheap as 19 USD, older wifi tech less than 5 USD) wifi cards and use them with some USB bridges to get the flexibility of USB without the annoyance of dealing with e.g. Realtek's USB drivers. At this point, I've already gone way farther down the rabbit hole than I intended to.

Maybe this won't work, but the fact that I see devices like this and the mPCIe card I linked above makes me think it might work.

[ghost]

There's no such thing as a "USB <-> PCIe bridge". (there's certainly no kernel driver mainline for such a thing)

It's either an adapter to expose USB signals from M.2 on a USB connector, or a bridge between a specific functions of USB and PCIe devices. (like NVMe <-> USB mass storage)

[codebling]

Realtek, JMicron and Asmedia all make products called "USB to PCIe bridge" and documentation for these often describe the chip as acting as a PCIe controller. This is what led me to naively hope (with no prior research) that plugging an M.2 into a 5$ adapter might work, and clearly it's far more complicated than that. It does seem like you can do crazy things with these chips (GPIO and I2C supported) but they are definitely geared towards NVMe drives and it's somewhat difficult to find information. Linux kernel does support PCI non-transparent bridges, which (because you can only have a single PCIe root) allows PCIe addresses from another PCIe root to be mapped into the same address space. I'm still really not sure it works this way.

[morrownr]

The adventure continues...

[smeep0]

I happen to have a RTL8832AU mini-PCIe to USB 3.0 WiFi6 adapter from a brand named XDO, and I'm having trouble trying to let it be recognized in my Kali Linux install in VirtualBox. It can be treated as a bridge connection just fine, but when trying to recognize it as a USB adapter, VirtualBox would give me an error.

And then I read this article. I was hoping someone would write RTL8832AU chipset drivers for people unfortunate enough to be stuck with said USB Wi-Fi adapters. Any chance as to how to get Linux to support this adapter?

[codebling]

@smeep0 see responses in #219