нестабильный Wi-Fi на Lenovo z50-70 (Ubuntu 15.04)

Я использую Ubuntu 15.04 на Lenovo Z50-70. Мой Wi-Fi нестабилен, это получает разъединение снова и снова и просит пароль.

Примечание: пароль, который я ввел, является корректными и другими пользователями на окнах, не имеют никакой проблемы с Wi-Fi.

вывод 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@0000:01:00.0
   logical name: eth0
   version: 10
   serial: 68:f7:28:74:fd:06
   size: 100Mbit/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=full firmware=rtl8168g-3_0.0.1 04/23/13 ip=192.168.2.6 latency=0 link=yes multicast=yes port=MII speed=100Mbit/s
   resources: irq:45 ioport:4000(size=256) memory:c3504000-c3504fff memory:c3500000-c3503fff
  *-network DISABLED
   description: Wireless interface
   product: QCA9565 / AR9565 Wireless Network Adapter
   vendor: Qualcomm Atheros
   physical id: 0
   bus info: pci@0000:02:00.0
   logical name: wlan0
   version: 01
   serial: 5c:93:a2:a3:59:55
   width: 64 bits
   clock: 33MHz
   capabilities: pm msi pciexpress bus_master cap_list rom ethernet physical wireless
   configuration: broadcast=yes driver=ath9k driverversion=4.0.7-040007-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11bgn
   resources: irq:19 memory:c3400000-c347ffff memory:c3480000-c348ffff

вывод rfkill list:

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

вывод lspci -nn | grep Net

02:00.0 Network controller [0280]: Qualcomm Atheros QCA9565 / AR9565 Wireless Network Adapter [168c:0036] (rev 01)