Ubuntu 16.04 Wifi keep disconnecting

Question

I am using UBUNTU 16.04. My wifi keep disconnecting again and again!! The output of lspci -knn | grep Net -A2 is:

06:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter [10ec:b723]
DeviceName:  
Subsystem: Hewlett-Packard Company RTL8723BE PCIe Wireless Network Adapter [103c:2231]

Output of lsusb is:

Bus 002 Device 003: ID 0bda:b001 Realtek Semiconductor Corp. 
Bus 002 Device 002: ID 0438:7900 Advanced Micro Devices, Inc. 
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 004: ID 064e:c341 Suyin Corp. 
Bus 001 Device 003: ID 138a:0050 Validity Sensors, Inc. Swipe Fingerprint Sensor
Bus 001 Device 002: ID 0438:7900 Advanced Micro Devices, Inc. 
Bus 001 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 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Output of lspci is:

00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1566
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Mullins [Radeon R4/R5 Graphics] (rev 05)
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Kabini HDMI/DP Audio
00:02.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 156b
00:02.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Functions 5:1
00:02.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Functions 5:1
00:02.3 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Functions 5:1
00:02.4 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Functions 5:1
00:08.0 Encryption controller: Advanced Micro Devices, Inc. [AMD] Device 1537
00:10.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB XHCI Controller (rev 11)
00:11.0 SATA controller: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode]
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 39)
00:13.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 39)
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 42)
00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD] FCH Azalia Controller (rev 02)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 11)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1580
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1581
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1582
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1583
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1584
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1585
01:00.0 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Jet XT [Radeon R5 M240] (rev ff)
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 10)
06:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter
07:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5227 PCI Express Card Reader (rev 01)

Output of dmesg | grep -i firmware is:

[    0.326620] [Firmware Bug]: ACPI: BIOS _OSI(Linux) query ignored
[    0.894754] [Firmware Bug]: ACPI: No _BQC method, cannot determine initial brightness
[    0.896423] [Firmware Bug]: ACPI: No _BQC method, cannot determine initial brightness
[    0.905790] acpi PNP0A08:00: [Firmware Info]: MMCONFIG for domain 0000 [bus 00-3f] only partially covers this bridge
[    1.940849] [Firmware Bug]: ACPI: No _BQC method, cannot determine initial brightness
[    1.940874] [Firmware Bug]: ACPI: No _BQC method, cannot determine initial brightness
[    2.074380] [drm] Found VCE firmware/feedback version 40.2.2 / 15!
[   10.624914] rtl8723be: Using firmware rtlwifi/rtl8723befw.bin

Solution

I have this problem with one of my laptops every time I do a clean install. The Realtek network adapter doesn't get along well with Linux.

This is the method I use to fix it

In the terminal type the following commands:

sudo apt-get install linux-headers-generic build-essential git
git clone https://github.com/lwfinger/rtlwifi_new.git
cd rtlwifi_new
make
sudo make install
sudo modprobe rtl8723be

That always gets me working right on the one machine I have with a Realtek adapter.

Comments

[Umar Asghar]

when I type this command sudo modprobe rtl8723be, I get this error. modprobe: ERROR: could not insert 'rtl8723be': Unknown symbol in module, or unknown parameter (see dmesg).

[Umar Asghar]

and what about for other adapter means other than Realtek?

[Robin Hood]

This answer ( askubuntu.com/questions/717685/… ) seems to be more complete.