Have I found the Sang Real of wifi adapters for my Linux box? It looks like it!

Plug and play wifi for Ubuntu

It just works.

My ISP offered an updated router and the old one was only just holding it together and giving us some pretty poor speeds. The problem really was the RJ11 extension cable – so the new router (TalkTalk HG533 [by Huawei]) was the impetus to finally go wireless on my main Kubuntu box (running 13.14 – Raring Ringtail – presently).

TL-WN823N doesn’t work

[Skip to TL-WN722N does work below to avoid my lament and go straight for the goodies!]

So. I already had a great wireless adapter. Like really good: the TP-Link 300Mbps Mini Wireless N USB Adapter TL-WN823N had given me some awesome service on an old Windows XP laptop enabling a strong fast connection which belied the size of the thing – about ½the size of a normal USB memory stick. Sadly it caused me many headaches on connection to my Ubuntu.

The best thread I found was “RealTek RTL-8188CUs working well-how to“. But there are many examples of forum threads with woes aplenty over attempting to use a Realtek based wifi adapter, not necessarily those using the 8192 hardware. That good thread had links to the download from Realtek allowing you to compile the adapter code … but only for kernels from ~2.6 to ~3.0. As I’m on 3.8.0-30 (for AMD64) that proved futile.

But wait there’s more. There was a patch too – oh joy. Patch applied (thanks to Timothy), old kernel modules blacklisted, new modules sudo make install-ed. It works! For a second and the crashes the whole computer. A hard crash, not even a SSH session live in the background on this one, not even SysReq REISUB magic invocations could cure it (that’s not happened to me on Linux for a long time). Futzing around with the code and settings and putting the USB in and out and resetting and unsetting and generally messing with everything possible didn’t produce a solution. Sadly neither the patch nor the .deb (with DKMS support) would work for me. Like I say it just crashed and all the logs had was a few lines of ^@^@^@ (or something like that).

So then the real challenge starts. Try and find something that will work.

TL-WN722N does work

Hooray!

In the end I just decided to buy something that looked possible and see if it worked. Thankfully I only needed one iteration to hit on a good – so far – purchase. It can out perform my broadband connection so there’s nothing more I need to look for I finally found a wifi adapter that just works on Linux (aff link to Amazon product page).

PS: don’t blame me if it doesn’t work for you!!

Fine details of the adapter

It’s using the Atheros ath9k modules:

k1210:~$ lsusb
Bus 001 Device 003: ID 0cf3:9271 Atheros Communications, Inc. AR9271 802.11n

k1210:~$ lsmod | grep ath9
ath9k_htc              91536  0
ath9k_common           14055  1 ath9k_htc
ath9k_hw              413629  2 ath9k_common,ath9k_htc
ath                    23827  3 ath9k_common,ath9k_htc,ath9k_hw
mac80211              606457  1 ath9k_htc
cfg80211              510937  3 ath,mac80211,ath9k_htc

iwlist reports that (MAC address altered):

k1210:~$ iwlist wlan15 scan
wlan15    Scan completed :
Cell 01 - Address: 4C:XX:XX:XX:XX:XX
Channel:4
Frequency:2.427 GHz (Channel 4)
Quality=55/70  Signal level=-55 dBm
Encryption key:on
ESSID:"TALKTALK-E8D140"
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 9 Mb/s
18 Mb/s; 36 Mb/s; 54 Mb/s
Bit Rates:6 Mb/s; 12 Mb/s; 24 Mb/s; 48 Mb/s
Mode:Master
Extra:tsf=00000008d0658151
Extra: Last beacon: 1081664ms ago
[...]
IE: WPA Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : TKIP CCMP
Authentication Suites (1) : PSK
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : TKIP CCMP
Authentication Suites (1) : PSK

and “iw list” gives more detail still of the capabilities:

k1210:~$ iw list
Wiphy phy0
Band 1:
Capabilities: 0x116e
HT20/HT40
SM Power Save disabled
RX HT20 SGI
RX HT40 SGI
RX STBC 1-stream
Max AMSDU length: 3839 bytes
DSSS/CCK HT40
Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
Minimum RX AMPDU time spacing: 8 usec (0x06)
HT TX/RX MCS rate indexes supported: 0-7
Frequencies:
* 2412 MHz [1] (20.0 dBm)
* 2417 MHz [2] (20.0 dBm)
* 2422 MHz [3] (20.0 dBm)
* 2427 MHz [4] (20.0 dBm)
* 2432 MHz [5] (20.0 dBm)
* 2437 MHz [6] (20.0 dBm)
* 2442 MHz [7] (20.0 dBm)
* 2447 MHz [8] (20.0 dBm)
* 2452 MHz [9] (20.0 dBm)
* 2457 MHz [10] (20.0 dBm)
* 2462 MHz [11] (20.0 dBm)
* 2467 MHz [12] (20.0 dBm)
* 2472 MHz [13] (20.0 dBm)
* 2484 MHz [14] (disabled)
Bitrates (non-HT):
* 1.0 Mbps
* 2.0 Mbps (short preamble supported)
* 5.5 Mbps (short preamble supported)
* 11.0 Mbps (short preamble supported)
* 6.0 Mbps
* 9.0 Mbps
* 12.0 Mbps
* 18.0 Mbps
* 24.0 Mbps
* 36.0 Mbps
* 48.0 Mbps
* 54.0 Mbps
max # scan SSIDs: 4
max scan IEs length: 2257 bytes
Coverage class: 0 (up to 0m)
Supported Ciphers:
* WEP40 (00-0f-ac:1)
* WEP104 (00-0f-ac:5)
* TKIP (00-0f-ac:2)
* CCMP (00-0f-ac:4)
Available Antennas: TX 0 RX 0
Supported interface modes:
* IBSS
* managed
* AP
* AP/VLAN
* monitor
* P2P-client
* P2P-GO
software interface modes (can always be added):
* AP/VLAN
* monitor
valid interface combinations:
* #{ managed, P2P-client } <= 2, #{ AP, P2P-GO } <= 2,
total <= 2, #channels <= 1
Supported commands:
* new_interface
* set_interface
* new_key
* new_beacon
* new_station
* new_mpath
* set_mesh_params
* set_bss
* authenticate
* associate
* deauthenticate
* disassociate
* join_ibss
* join_mesh
* remain_on_channel
* set_tx_bitrate_mask
* action
* frame_wait_cancel
* set_wiphy_netns
* set_channel
* set_wds_peer
* Unknown command (84)
* Unknown command (87)
* Unknown command (85)
* Unknown command (89)
* Unknown command (92)
* testmode
* connect
* disconnect
Supported TX frame types:
* IBSS: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* managed: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* AP: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* AP/VLAN: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* mesh point: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* P2P-client: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* P2P-GO: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
* Unknown mode (10): 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
Supported RX frame types:
* IBSS: 0x40 0xb0 0xc0 0xd0
* managed: 0x40 0xd0
* AP: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
* AP/VLAN: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
* mesh point: 0xb0 0xc0 0xd0
* P2P-client: 0x40 0xd0
* P2P-GO: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
* Unknown mode (10): 0x40 0xd0
Device supports RSN-IBSS.
HT Capability overrides:
* MCS: ff ff ff ff ff ff ff ff ff ff
* maximum A-MSDU length
* supported channel width
* short GI for 40 MHz
* max A-MPDU length exponent
* min MPDU start spacing
Device supports TX status socket option.
Device supports HT-IBSS.