Arch Linux

66.exe

Member

Registered: 2016-06-14

Posts: 18

[SOLVED] iwd not finding RTL8188EUS wifi adapter

I bought a tp-link wifi adapter (TL-WN725N) to use on my desktop computer.

When I do lsusb it is shown as Realtek Semiconductor Corp. RTL8188EUS 802.11n Wireless Network Adapter.

I installed iwd and started/enabled the service. When I run iwctl to get into the interactive prompt and run the device list command, then nothing is listed.

If I run the station list command then I get

No devices in Station mode available.

At first I thought that the kernel module for my wifi adapter wasn't loaded. But when I run lsmod | grep 8818 I get

r8188eu                        798720     0

If I unplug the adapter it no longer shows in the output of lsmod.

I'm not sure what else to try.

Last edited by 66.exe (2021-12-22 07:08:22)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,672

Re: [SOLVED] iwd not finding RTL8188EUS wifi adapter

Check dmesg on whether there are errors initializing the device. check whether you even have a device node in e.g. ip addr there's a slight possibility this driver only sets up the old connection method which would mandate wpa_supplicant rather than iwd

OT but realtek wifi devices have a very spotty reputation in terms of drivers/driver stability. If you just bought it you'll potentially avoid a lot of headache by returning it and opting for either a qualcomm or intel based pci card or if it has to be USB you probably  want to look for mediathek devices, see https://wikidevi.wi-cat.ru/Main_Page to help with chipset <-> product mapping

But that's just a rant on my side, we'd still need more info on your current setup.

66.exe

Member

Registered: 2016-06-14

Posts: 18

Re: [SOLVED] iwd not finding RTL8188EUS wifi adapter

Here's my output for ip a

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: enp3s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000
    link/ether d8:cb:8a:55:1b:d9 brd ff:ff:ff:ff:ff:ff
4: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
    link/ether 7c:c2:c6:19:4b:0f brd ff:ff:ff:ff:ff:ff

The wlan0 interface disappears when I unplug the adapter.

Only relevant output in dmesg

[   32.885552] usb 3-2: new high-speed USB device number 4 using xhci_hcd
[   33.025885] usb 3-2: New USB device found, idVendor=0bda, idProduct=8179, bcdDevice= 0.00
[   33.025888] usb 3-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[   33.025890] usb 3-2: Product: 802.11n NIC
[   33.025891] usb 3-2: Manufacturer: Realtek
[   33.025892] usb 3-2: SerialNumber: 00E04C0001
[   33.043351] r8188eu: module is from the staging directory, the quality is unknown, you have been warned.
[   33.047906] Chip Version Info: CHIP_8188E_Normal_Chip_TSMC_D_CUT_1T1R_RomVer(0)
[   33.069591] EEPROM ID = 0x8129
[   33.070001] usbcore: registered new interface driver r8188eu
[   33.079522] R8188EU: Firmware Version 11, SubVersion 1, Signature 0x88e1
[   33.405730] MAC Address = 7c:c2:c6:19:4b:0f

No errors, but as you mentioned it might just be that this module/hardware is new and still bad quality. If that is the case would there not be errors though?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,672

Re: [SOLVED] iwd not finding RTL8188EUS wifi adapter

Not necessarily, according to this the device is technically there and detected. However as it's a staging driver I find it likely that it's using an older WLAN protocol driver (as in, the kernel interface that "all" the top level drivers connect to) which should be cfg80211 on anything actively maintained, and isn't on this example driver. This also isn't really a case of being new, that driver and chipset is quite a few years old, but the older rtl drivers just suck. It should™ be better for newer ones, but from what I've heard there are still a few gotchas.

In any case just from looking at the module depends then that isn't the case and you'll definitely won't be able to do that with iwd since it just supports drivers hooking into the cfg80211 interface. Test with wpa_supplicant which does support the older wext driver still. Alternatively there are some out of tree drivers/patchsets which might workk better e.g. https://aur.archlinux.org/packages/8188 … -dkms-git/ but this is apparently currently broken on 5.15 and would either need the linked patch applied or testing on linux-lts or so.

Last edited by V1del (2021-12-08 09:23:43)

66.exe

Member

Registered: 2016-06-14

Posts: 18

Re: [SOLVED] iwd not finding RTL8188EUS wifi adapter

Damn it. This is turning out to be an ordeal then. I just moved into a new place and don't have internet setup yet. I was hoping to use the adapter to just connect to my phone for the few days while I wait for fiber installation at the new place.

Thanks so much for your assistance I really appreciate it. I don't have the patience to do in depth troubleshooting right now, but I'll try the wpa_supplicant (and lts kernel) solution once things calm down in a few days. Hopefully I can close the issue then.

Also I did try install the module from the AUR package on the current kernel earlier, and yes it did not work. But what is the difference between that module and the r8188eu module?

66.exe

Member

Registered: 2016-06-14

Posts: 18

Re: [SOLVED] iwd not finding RTL8188EUS wifi adapter

Hi there, sorry about the delay. I got it working. Using wpa_supplicant with the -Dwext flag was the solution as you suspected. https://wiki.archlinux.org/title/Wpa_su … e_hardware

Thanks again for the assistance.