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pessoa

Member

Registered: 2020-11-09

Posts: 5

[SOLVED] Cannot use USB WiFi Adapter with mt7921au chipset

I purchased a Comfast CF-952AX USB WiFi adapter using the mt7921au chipset.

According to Linux Wireless Wiki, this chipset is supported by the 'mt76' driver since 5.18+. However, I can't use the adapter after plugging it in.

I'm using the latest Arch Linux.

$ uname -sr
Linux 6.2.2-arch1-1

According to  morrownr@github

One adapter in particular, Comfast CF-952AX, has been creating confusion. A very recent user report indicates that this adapter does have a mt7921au chipset but the device ID is not in the in-kernel driver yet which causes the adapter to not be recognized. However, you can find ads that say the CF-952AX uses a rtl8832au chipset so there is confusion. The user that reported the adapter as having the mt7921au chipset submitted a patch to Linux-wireless to have the ID merged into the kernel. More info as this issue developes.

After plugin the CF-952AX USB WiFi adapter, I get:

$ lsusb
Bus 002 Device 006: ID 3574:6211 MediaTek Inc. Wireless_Device

$ lsusb -t
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/8p, 10000M
    |__ Port 6: Dev 6, If 0, Class=Vendor Specific Class, Driver=, 5000M

$ ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp3s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN mode DEFAULT group default qlen 1000
    link/ether d8:bb:c1:c5:41:c3 brd ff:ff:ff:ff:ff:ff
4: enp0s20f0u10: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN mode DEFAULT group default qlen 1000
    link/ether 02:7a:42:58:31:3c brd ff:ff:ff:ff:ff:ff

Following commands output nothing

$ iw list
$ iw dev
$ lsmod | grep mt76
# dmesg | grep mt76

The output of `lsusb -v` is in link http://0x0.st/HiBb.txt

The USB Wifi adapter is not recognized by the system, So I can't use it. As "lsmod | grep mt76" returns nothing, I tried manually load it;

sudo modprobe mt76_usb

Then

➜  ~ lsmod | grep mt76
mt76_usb               49152  0
mt76                  122880  1 mt76_usb
mac80211             1503232  1 mt76
cfg80211             1277952  2 mt76,mac80211

But nothing else changes.

What can I do to use this USB Wifi adapter?

Last edited by pessoa (2023-03-10 13:08:52)

loqs

Member

Registered: 2014-03-06

Posts: 17,935

Re: [SOLVED] Cannot use USB WiFi Adapter with mt7921au chipset

Have you looked at https://github.com/morrownr/USB-WiFi/di … nt-5101944

pessoa

Member

Registered: 2020-11-09

Posts: 5

Re: [SOLVED] Cannot use USB WiFi Adapter with mt7921au chipset

Have you looked at https://github.com/morrownr/USB-WiFi/di … nt-5101944

Thank you!

I tried

su
modprobe mt7921u
echo 3574 6211 > /sys/bus/usb/drivers/mt7921u/new_id

And then the USB Wifi adapter works. I can use it to connect to Wifi now.

$ lsusb -d 3574:6211 -t
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M
    |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/6p, 480M
        |__ Port 1: Dev 3, If 0, Class=Vendor Specific Class, Driver=mt7921u, 480M