# Troubles with RTL8192CU

## OYTIS

Greetings!

I decided to get a more powerful WiFi adapter for my laptop and bought a TP-WN822N device, which happened to be based on RTL8192CU. Under wicd it scans the network fine, but every time I try to connect to WPA network it says "Bad password". If I use wpa_supplicant directly, dhcpcd sometimes drops after unsuccessful waiting for carrier and sometimes produces rather strange output:

```

>> dhcpcd -A wlan1

>> dhcpcd[3944]: version 5.6.4 starting

dhcpcd[3944]: wlan1: sending IPv6 Router Solicitation

dhcpcd[3944]: wlan1: rebinding lease of 192.168.1.2

dhcpcd[3944]: wlan1: sending IPv6 Router Solicitation

dhcpcd[3944]: wlan1: broadcasting for a lease

dhcpcd[3944]: wlan1: sending IPv6 Router Solicitation

dhcpcd[3944]: wlan1: sending IPv6 Router Solicitation

dhcpcd[3944]: wlan1: no IPv6 Routers available

dhcpcd[3944]: timed out

```

When using wlan0 (internal adapter), everything is OK.

dmesg says that module and the firmware are loaded correctly, but some obscure messages are present.

```
[  562.032434] rtl8192cu: MAC auto ON okay!

[  562.067178] rtl8192cu: Tx queue select: 0x05

[  563.458962] rtl8192cu 1-2:1.0 wlan1: disabling HT as WMM/QoS is not supported by the AP

[  563.458968] rtl8192cu 1-2:1.0 wlan1: disabling VHT as WMM/QoS is not supported by the AP

[  567.358095] rtl8192cu 1-2:1.0 wlan1: disabling HT as WMM/QoS is not supported by the AP

[  567.358106] rtl8192cu 1-2:1.0 wlan1: disabling VHT as WMM/QoS is not supported by the AP

[  571.257524] rtl8192cu 1-2:1.0 wlan1: disabling HT as WMM/QoS is not supported by the AP

[  571.257535] rtl8192cu 1-2:1.0 wlan1: disabling VHT as WMM/QoS is not supported by the AP

[  575.150548] rtl8192cu 1-2:1.0 wlan1: disabling HT as WMM/QoS is not supported by the AP

[  575.150560] rtl8192cu 1-2:1.0 wlan1: disabling VHT as WMM/QoS is not supported by the AP

[  579.075184] rtl8192cu 1-2:1.0 wlan1: disabling HT as WMM/QoS is not supported by the AP

[  579.075195] rtl8192cu 1-2:1.0 wlan1: disabling VHT as WMM/QoS is not supported by the AP

[  582.958527] rtl8192cu 1-2:1.0 wlan1: disabling HT as WMM/QoS is not supported by the AP

[  582.958538] rtl8192cu 1-2:1.0 wlan1: disabling VHT as WMM/QoS is not supported by the AP
```

Strangely enough, some ipv6 address is assigned to wlan1:

```
wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500

        inet 192.168.1.4  netmask 255.255.255.0  broadcast 192.168.1.255

        inet6 fe80::8a9f:faff:fefa:f844  prefixlen 64  scopeid 0x20<link>

        ether 88:9f:fa:fa:f8:44  txqueuelen 1000  (Ethernet)

        RX packets 2928  bytes 2691521 (2.5 MiB)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 3005  bytes 430983 (420.8 KiB)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlan1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500

        inet6 fe80::fa1a:67ff:fe20:dd9b  prefixlen 64  scopeid 0x20<link>

        ether f8:1a:67:20:dd:9b  txqueuelen 1000  (Ethernet)

        RX packets 106  bytes 10829 (10.5 KiB)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 88  bytes 14443 (14.1 KiB)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
```

I would be grateful for any ideas and suggestions.

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## Vorlon

I had a very similar problem.  Unfortunately, I never solved it.   In my case, it was a very low cost Realtek RTL8188CUS USB WiFi Dongle.  Comments I read on line at Amazon said it should work.  Linux recognized it, and created wlan0. 

However, I could NEVER get the sucker to connect with Linux.   I tried WPA, WEP, and even wide-open security.  I even loaded Windows on the laptop as a test and tried the supplied driver.  it worked in Windows, but not in Linux.

I thought my unit my have been defective sinece it mechanically fell apart when I pulled it from a tight USB port.  The supplier sent a second unit (no charge) and it had the exact same problem.

I concluded that there was SOMETHING goofy about the realtek ROM on the chip that made it incompatible with Linux.  

I ended up buying a different low-cost USB WiFi dongle, and now get internet without any trouble.  But the RTL8188CUS is sitting in my parts drawer unused and lonely.

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## OYTIS

Actually, one of the motivations for buying this device was to get rid of buggy Realtek driver (my internal wlan tranciever is also realtek). But the same model can be based on a thousand different chips, so it's like a lottery.

OK, I updated to kernel version 3.10.7 and now it DOES get an ip address in wicd, but disconnects after a few seconds. In dmesg it looks like

```

Connection phase:

[  139.245628] wlan1: authenticate with 00:19:cb:8c:97:8b

[  139.246990] wlan1: send auth to 00:19:cb:8c:97:8b (try 1/3)

[  139.248495] wlan1: authenticated

[  139.248679] rtl8192cu 1-2:1.0 wlan1: disabling HT as WMM/QoS is not supported by the AP

[  139.248684] rtl8192cu 1-2:1.0 wlan1: disabling VHT as WMM/QoS is not supported by the AP

[  139.251646] wlan1: associate with 00:19:cb:8c:97:8b (try 1/3)

[  139.266464] wlan1: RX AssocResp from 00:19:cb:8c:97:8b (capab=0x11 status=0 aid=1)

[  139.266525] wlan1: associated

[  139.266589] IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
```

```

And sudden disconnection after a while

[  147.111965] rtlwifi:rtl_watchdog_wq_callback():<0-0> AP off, try to reconnect now

[  147.111998] wlan1: Connection to AP 00:19:cb:8c:97:8b lost

[  147.125527] cfg80211: Calling CRDA to update world regulatory domain

[  147.997424] wlan1: authenticate with 00:19:cb:8c:97:8b

[  148.010256] wlan1: send auth to 00:19:cb:8c:97:8b (try 1/3)

[  148.113277] wlan1: send auth to 00:19:cb:8c:97:8b (try 2/3)

[  148.216568] wlan1: send auth to 00:19:cb:8c:97:8b (try 3/3)

[  148.320004] wlan1: authentication with 00:19:cb:8c:97:8b timed out

[  148.400551] rtl8192cu: MAC auto ON okay!

[  148.435542] rtl8192cu: Tx queue select: 0x05

[  148.824892] IPv6: ADDRCONF(NETDEV_UP): wlan1: link is not ready

[  148.970864] r8169 0000:01:00.0 eth0: link down

[  148.970925] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready

```

Still <censored> IPv6.

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## Schnulli

the Realtek USB Dongle are problematic, reasons, often became to hot and the they start suck (sorry), driver problems and often, problems with different APś bec of Protocol differences.

Ihad some RTL Dongle running and used old drivers from the Taiwan Web Page,they worked, but not with all APś,  if u cant find them there, i asked the Realtek DEV (by the way they are very friendly and Linux is welcome there  :Wink:  )

When u start high bandwidth usage with this dongles on a not perfectly working AP... the trouble starts

greetz

----------

