USB wifi não conecta após a atualização do Ubuntu 10.04 para 12.04

Question

Acabei de atualizar o Ubuntu de 10.04 para 12.04. Mas após a atualização, não consigo me conectar ao roteador wifi da minha casa. Eu tentei conectá-lo com meu dispositivo Android, ele funciona bem . Às vezes, ele se conecta ao meu wifi doméstico, mas não há internet disponível.

A configuração do dispositivo está abaixo:

saquib@saquib-laptop:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr e8:11:32:20:de:7a  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:41 Base address:0xc000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:3453 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3453 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:271550 (271.5 KB)  TX bytes:271550 (271.5 KB)

wlan0     Link encap:Ethernet  HWaddr 08:10:76:c5:2b:d2  
          inet6 addr: fe80::a10:76ff:fec5:2bd2/64 Scope:Link
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:37 errors:0 dropped:0 overruns:0 frame:0
          TX packets:268 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:5276 (5.2 KB)  TX bytes:32395 (32.3 KB)

saquib@saquib-laptop:~$ iwconfig
lo        no wireless extensions.

wlan0     IEEE 802.11bgn  ESSID:off/any  
          Mode:Managed  Access Point: Not-Associated   Tx-Power=20 dBm   
          Retry  long limit:7   RTS thr=2347 B   Fragment thr:off
          Power Management:off

eth0      no wireless extensions.

saquib@saquib-laptop:~$ rfkill list
0: hci0: Bluetooth
    Soft blocked: no
    Hard blocked: no
1: phy0: Wireless LAN
    Soft blocked: no
    Hard blocked: no

saquib@saquib-laptop:~$ sudo lshw -C network
  *-network               
       description: Ethernet interface
       product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:04:00.0
       logical name: eth0
       version: 06
       serial: e8:11:32:20:de:7a
       size: 10Mbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl_nic/rtl8168e-2.fw latency=0 link=no multicast=yes port=MII speed=10Mbit/s
       resources: irq:41 ioport:3000(size=256) memory:fc900000-fc900fff memory:fca04000-fca07fff
  *-network
       description: Wireless interface
       physical id: 4
       bus info: usb@2:1.2
       logical name: wlan0
       serial: 08:10:76:c5:2b:d2
       capabilities: ethernet physical wireless
       configuration: broadcast=yes driver=rtl8192cu driverversion=3.2.0-54-generic firmware=N/A link=no multicast=yes wireless=IEEE 802.11bgn


saquib@saquib-laptop:~$ lspci
00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 02)
00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02)
00:16.0 Communication controller: Intel Corporation 5 Series/3400 Series Chipset HECI Controller (rev 06)
00:1a.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 05)
00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 05)
00:1c.3 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 4 (rev 05)
00:1d.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev a5)
00:1f.0 ISA bridge: Intel Corporation Mobile 5 Series Chipset LPC Interface Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 4 port SATA AHCI Controller (rev 05)
00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 05)
00:1f.6 Signal processing controller: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem (rev 05)
04:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06)
3f:00.0 Host bridge: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers (rev 02)
3f:00.1 Host bridge: Intel Corporation Core Processor QuickPath Architecture System Address Decoder (rev 02)
3f:02.0 Host bridge: Intel Corporation Core Processor QPI Link 0 (rev 02)
3f:02.1 Host bridge: Intel Corporation Core Processor QPI Physical 0 (rev 02)
3f:02.2 Host bridge: Intel Corporation Core Processor Reserved (rev 02)
3f:02.3 Host bridge: Intel Corporation Core Processor Reserved (rev 02)


saquib@saquib-laptop:~$ nm-tool 

NetworkManager Tool

State: disconnected

- Device: wlan0 ----------------------------------------------------------------
  Type:              802.11 WiFi
  Driver:            rtl8192cu
  State:             disconnected
  Default:           no
  HW Address:        08:10:76:C5:2B:D2

  Capabilities:

  Wireless Properties
    WEP Encryption:  yes
    WPA Encryption:  yes
    WPA2 Encryption: yes

  Wireless Access Points 
    TP-LINK_E86B12:  Infra, A0:F3:C1:E8:6B:12, Freq 2417 MHz, Rate 54 Mb/s, Strength 99 WPA WPA2


- Device: eth0 -----------------------------------------------------------------
  Type:              Wired
  Driver:            r8169
  State:             unavailable
  Default:           no
  HW Address:        E8:11:32:20:DE:7A

  Capabilities:
    Carrier Detect:  yes

  Wired Properties
    Carrier:         off

    

Answer 1

Antes de mais nada, verifique se você tem os pré-requisitos necessários:

sudo apt-get install linux-headers-generic build-essential dkms git

Clone o driver atualizado com git :

git clone https://github.com/pvaret/rtl8192cu-fixes.git

Configure como um módulo DKMS:

sudo dkms add ./rtl8192cu-fixes

Crie e instale o driver:

sudo dkms install 8192cu/1.8

Atualize a lista de módulos:

sudo depmod -a

Assegure-se de que o driver do kernel nativo (e interrompido) esteja na lista negra:

sudo cp ./rtl8192cu-fixes/blacklist-native-rtl8192.conf /etc/modprobe.d/

Não vamos nos arriscar. Instrua o Ubuntu a carregar o novo driver quando ele for iniciado.

echo 8192cu | sudo tee -a /etc/modules

Reinicie.

Você terminou.

_{Graças a P. Vareta para essa correção incrível.}