Experiment with support for TP-LINK TX20U (not PLUS!)

[lordjim1985]

Hello,

I'm writing to inform You that made an experiment with TP-LINK TX20U (not Plus Version) and added in os_dep/linux/usb_intf.c following identifiers: 0x35bc, 0x0100.

To my suprise everything works quite well even with 802.11ax. I'm testing the device as Access Point with hostapd.

It is relatively cheap AX1800 dongle.

TP-LINK officialy does not provide a linux driver.

Do you have any recommendations for any additional testing?

[morrownr]

Hi @lordjim1985

Do you have any recommendations for any additional testing?

Yes. It would help confirm that the patch I just submitted is correct if you could remove the driver, delete the driver subdirectory and then start over with a fresh download. If that works, things checkout good. Let me know.

To remove the driver:

$ sudo sh remove-driver.sh

Thanks for the info.

[lordjim1985]

Hi there,

I've removed my changes. Cleaned the build dir and pulled your changes. I've built the driver sucessfully on Ubuntu 23.10 Mantic. The driver works well.

I'm using the following hostapd.conf:

logger_syslog=-1 logger_syslog_level=2 logger_stdout=-1 logger_stdout_level=2 interface=wlx74fece4c7190 bridge=br0 driver=nl80211 hw_mode=a country_code=PL channel=36 vht_oper_centr_freq_seg0_idx=42 ssid=ExampleSSIDofWiFiNetwork ignore_broadcast_ssid=0 ieee80211d=1 ieee80211n=1 ieee80211w=1 ht_capab=[MAX-AMSDU-7935][HT40+][SHORT-GI-20][SHORT-GI-40][DSSS_CCK-40][TX-STBC][RX-STBC1] ieee80211ac=1 ieee80211ax=1 vht_capab=[SHORT-GI-80][SU-BEAMFORMEE] vht_oper_chwidth=1 auth_algs=1 wpa=2 wpa_passphrase=SecretPasshphrase wpa_key_mgmt=WPA-PSK WPA-PSK-SHA256 SAE rsn_pairwise=CCMP sae_require_mfp=1 macaddr_acl=0 wmm_enabled=1

And the following settings in 8852bu.conf :

options 8852bu rtw_switch_usb_mode=0 rtw_he_enable=1 rtw_vht_enable=1 rtw_dfs_region_domain=0.

I'm getting about 32.5MB/s on 802.11ax with WPA3 enabled.

With the following options:

options 8852bu rtw_switch_usb_mode=1 rtw_he_enable=2 rtw_vht_enable=2 rtw_dfs_region_domain=0.

I'm getting about 37-40MB/s on 802.11ax with WPA3 enabled.

[lordjim1985]

Hi,

Im here with an update. It seems that enabling 802.11n mode only causes the driver to crash. For some reason the 5Ghz options are working while the 802.11n are causing a crash. What information i can provide for futher debugging?

[lordjim1985]

Hello,

another update. After upgrading Ubuntu 23.10 to Ubuntu 24.04 the 802.11n mode also works, though quite slow it is operational.

The kernel was changed from 6.5.0 to 6.8.0 during upgrade.

[lordjim1985]

Hi,

the performance on 802.11n channel 4 was low. I've switched to channel 11 and not I get 7.86MB/s on 802.11n. So as far as I can tell it works. Though some messages in dmesg are worrying me. I'm pasting the output:

[ 3473.989582] UBSAN: array-index-out-of-bounds in /var/lib/dkms/rtl8852bu/1.19.3/build/os_dep/linux/wifi_regd.c:264:18 [ 3473.989587] index 0 is out of range for type 'RT_CHANNEL_INFO [*]' [ 3473.989589] CPU: 1 PID: 13721 Comm: modprobe Tainted: G OE 6.8.0-31-generic #31-Ubuntu [ 3473.989592] Hardware name: Shenzhen DOKE electronic co., LTD MP80/MP80, BIOS 5.26 09/27/2023 [ 3473.989593] Call Trace: [ 3473.989596] [ 3473.989600] dump_stack_lvl+0x48/0x70 [ 3473.989612] dump_stack+0x10/0x20 [ 3473.989614] ubsan_handle_out_of_bounds+0xc6/0x110 [ 3473.989619] rtw_update_wiphy_regd+0x11b/0x560 [8852bu] [ 3473.989866] rtw_regd_change_complete_sync+0x5b/0x150 [8852bu] [ 3473.990023] ? rtw_regd_change_complete_sync+0x5b/0x150 [8852bu] [ 3473.990184] rtw_wiphy_register+0xb8/0xc0 [8852bu] [ 3473.990342] rtw_cfg80211_dev_res_register+0x15/0x30 [8852bu] [ 3473.990495] rtw_os_ndevs_register+0x21/0xf0 [8852bu] [ 3473.990643] rtw_os_ndevs_init+0x34/0x50 [8852bu] [ 3473.990793] rtw_dev_probe+0x589/0x5d0 [8852bu] [ 3473.990949] usb_probe_interface+0xeb/0x300 [ 3473.990954] really_probe+0x1c4/0x410 [ 3473.990957] driver_probe_device+0x8c/0x180 [ 3473.990959] driver_probe_device+0x24/0xd0 [ 3473.990961] driver_attach+0x10b/0x210 [ 3473.990963] ? _pfxdriver_attach+0x10/0x10 [ 3473.990965] bus_for_each_dev+0x8a/0xf0 [ 3473.990968] driver_attach+0x1e/0x30 [ 3473.990970] bus_add_driver+0x156/0x260 [ 3473.990972] driver_register+0x5e/0x130 [ 3473.990974] usb_register_driver+0x83/0x170 [ 3473.990978] ? pfx_rtw_drv_entry+0x10/0x10 [8852bu] [ 3473.991122] rtw_drv_entry+0x55/0xff0 [8852bu] [ 3473.991272] ? pfx_rtw_drv_entry+0x10/0x10 [8852bu] [ 3473.991425] do_one_initcall+0x5b/0x340 [ 3473.991431] do_init_module+0xc0/0x2c0 [ 3473.991436] load_module+0xba1/0xcf0 [ 3473.991439] init_module_from_file+0x96/0x100 [ 3473.991440] ? init_module_from_file+0x96/0x100 [ 3473.991443] idempotent_init_module+0x11c/0x2b0 [ 3473.991445] x64_sys_finit_module+0x64/0xd0 [ 3473.991447] x64_sys_call+0x1d6e/0x25c0 [ 3473.991448] do_syscall_64+0x7f/0x180 [ 3473.991453] ? syscall_exit_to_user_mode+0x86/0x260 [ 3473.991456] ? do_syscall_64+0x8c/0x180 [ 3473.991458] ? do_syscall_64+0x8c/0x180 [ 3473.991460] ? x64_sys_openat+0x55/0xa0 [ 3473.991464] ? syscall_exit_to_user_mode+0x86/0x260 [ 3473.991466] ? do_syscall_64+0x8c/0x180 [ 3473.991468] ? do_syscall_64+0x8c/0x180 [ 3473.991470] ? irqentry_exit+0x43/0x50 [ 3473.991473] ? exc_page_fault+0x94/0x1b0 [ 3473.991476] entry_SYSCALL_64_after_hwframe+0x73/0x7b [ 3473.991480] RIP: 0033:0x7222df52725d [ 3473.991500] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8b bb 0d 00 f7 d8 64 89 01 48 [ 3473.991502] RSP: 002b:00007ffec42cb798 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 3473.991505] RAX: ffffffffffffffda RBX: 00005f888b48de60 RCX: 00007222df52725d [ 3473.991506] RDX: 0000000000000004 RSI: 00005f888b48e300 RDI: 0000000000000003 [ 3473.991507] RBP: 00007ffec42cb850 R08: 0000000000000040 R09: 00007ffec42cb7e0 [ 3473.991509] R10: 00007222df603b20 R11: 0000000000000246 R12: 00005f888b48e300 [ 3473.991510] R13: 0000000000040000 R14: 00005f888b48df90 R15: 00005f888b48e300 [ 3473.991512] [ 3473.991529] ---[ end trace ]---

[morrownr]

@lordjim1985

I can fix that USBAN problem as I have time but it likely is not causing any problems.

I can help you more, especially with AP mode, as I have some spare time... maybe this evening but please understand that this is not what I would call a good driver. I'm really disappointed in the WiFi 6 Linux driver from Realtek. If you can still return this adapter, you might want to consider that option.. The Main Menu here at this site has a lot of information that you may want to read:

https://github.com/morrownr/USB-WiFi

Scroll down. Menu items 1 and 2 are a good place to start.

[lordjim1985]

Ho @morrownr,

Well it is your free time so it is up to you :)

I can return it of course but it works quite well in Windows and thanks to you most of the functions I need under Linux are operational so simply speaking: i'll find uses for it.

Thanks for your great work and the information you provided. If you need me i'll also be available in the evening.

[morrownr]

@lordjim1985

I am going to go ahead and close this issue. If you need help with AP mode or you see another problem, Let me know.