i have a wifi connection problem in lenovo g580 on kubuntu-13.04-desktop-amd64.

ethernet cable is working properly but wifi does'nt connect

below are some hardware information

sudo lshw -class network gives

  *-network               
   description: Ethernet interface
   product: AR8162 Fast Ethernet
   vendor: Qualcomm Atheros
   physical id: 0
   bus info: pci@0000:01:00.0
   logical name: eth0
   version: 10
   serial: 20:89:84:3d:e9:10
   size: 100Mbit/s
   capacity: 100Mbit/s
   width: 64 bits
   clock: 33MHz
   capabilities: pm pciexpress msi msix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd autonegotiation
   configuration: autonegotiation=on broadcast=yes driver=alx driverversion=1.2.3 duplex=full firmware=N/A ip=192.168.0.106 latency=0 link=yes multicast=yes port=twisted pair speed=100Mbit/s
   resources: irq:16 memory:90500000-9053ffff ioport:2000(size=128)
  *-network
   description: Network controller
   product: BCM4313 802.11b/g/n Wireless LAN Controller
   vendor: Broadcom Corporation
   physical id: 0
   bus info: pci@0000:02:00.0
   version: 01
   width: 64 bits
   clock: 33MHz
   capabilities: pm msi pciexpress bus_master cap_list
   configuration: driver=bcma-pci-bridge latency=0
   resources: irq:17 memory:90400000-90403fff
  *-network
   description: Wireless interface
   physical id: 3
   logical name: wlan0
   serial: 68:94:23:fa:2c:d9
   capabilities: ethernet physical wireless
   configuration: broadcast=yes driver=brcmsmac driverversion=3.8.0-19-generic firmware=N/A link=no multicast=yes wireless=IEEE 802.11bgn

lsubs gives

Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 0489:e032 Foxconn / Hon Hai 
Bus 002 Device 003: ID 04f2:b2e2 Chicony Electronics Co., Ltd

lspci gives

00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09)
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
00:14.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB xHCI Host Controller (rev 04)
00:16.0 Communication controller: Intel Corporation 7 Series/C210 Series Chipset Family MEI Controller #1 (rev 04)
00:1a.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #2 (rev 04)
00:1b.0 Audio device: Intel Corporation 7 Series/C210 Series Chipset Family High Definition Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 1 (rev c4)
00:1c.1 PCI bridge: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 2 (rev c4)
00:1d.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #1 (rev 04)
00:1f.0 ISA bridge: Intel Corporation HM76 Express Chipset LPC Controller (rev 04)
00:1f.2 SATA controller: Intel Corporation 7 Series Chipset Family 6-port SATA Controller [AHCI mode] (rev 04)
00:1f.3 SMBus: Intel Corporation 7 Series/C210 Series Chipset Family SMBus Controller (rev 04)
01:00.0 Ethernet controller: Qualcomm Atheros AR8162 Fast Ethernet (rev 10)
02:00.0 Network controller: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller (rev 01)

Does anyone knows the solution?

rfkill list all gives

0: hci0: Bluetooth
    Soft blocked: no
    Hard blocked: no
1: phy0: Wireless LAN
    Soft blocked: yes
    Hard blocked: no
2: ideapad_wlan: Wireless LAN
    Soft blocked: yes
    Hard blocked: no
3: ideapad_bluetooth: Bluetooth
    Soft blocked: no
    Hard blocked: no