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ng.newbie
Asked: 2017-07-31 04:08:02 +0800 CST

Unable to connect to Wifi with Ubuntu 16.04

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I have just installed 16.04 on my HP-149tx alongside Windows. I am unable to access the Wifi from Ubuntu. The signal is too weak even if I hold the laptop close to the router.I can confirm this is a driver issue since I have flawless access to my Wifi from Windows.

What I did to try and rectify this issue is try to download and install the wifi drivers as per instructions specified over here. The problem I get when installing the driver is as follows-:

(Reading database ... 174937 files and directories currently installed.)
Preparing to unpack rtlwifi-new-dkms_0.10_all.deb ...

------------------------------
Deleting module version: 0.10
completely from the DKMS tree.
------------------------------
Done.
Unpacking rtlwifi-new-dkms (0.10) over (0.10) ...
Setting up rtlwifi-new-dkms (0.10) ...
Loading new rtlwifi-new-0.10 DKMS files...
First Installation: checking all kernels...
Building only for 4.8.0-36-generic
Building for architecture x86_64
Building initial module for 4.8.0-36-generic
Error! Bad return status for module build on kernel: 4.8.0-36-generic (x86_64)
Consult /var/lib/dkms/rtlwifi-new/0.10/build/make.log for more information.

Also the contents of make.log is as follows-:

DKMS make.log for rtlwifi-new-0.10 for kernel 4.8.0-36-generic (x86_64)
Sun Jul 30 17:10:27 IST 2017
make: Entering directory '/usr/src/linux-headers-4.8.0-36-generic'
  LD      /var/lib/dkms/rtlwifi-new/0.10/build/built-in.o
  CC [M]  /var/lib/dkms/rtlwifi-new/0.10/build/base.o
In file included from /var/lib/dkms/rtlwifi-new/0.10/build/base.c:30:0:
/var/lib/dkms/rtlwifi-new/0.10/build/wifi.h:1327:40: error: ‘IEEE80211_NUM_BANDS’ undeclared here (not in a function)
  struct ieee80211_supported_band bands[IEEE80211_NUM_BANDS];
                                        ^
/var/lib/dkms/rtlwifi-new/0.10/build/base.c:138:10: error: ‘IEEE80211_BAND_2GHZ’ undeclared here (not in a function)
  .band = IEEE80211_BAND_2GHZ,
          ^
/var/lib/dkms/rtlwifi-new/0.10/build/base.c:150:10: error: ‘IEEE80211_BAND_5GHZ’ undeclared here (not in a function)
  .band = IEEE80211_BAND_5GHZ,
          ^
scripts/Makefile.build:289: recipe for target '/var/lib/dkms/rtlwifi-new/0.10/build/base.o' failed
make[1]: *** [/var/lib/dkms/rtlwifi-new/0.10/build/base.o] Error 1
Makefile:1491: recipe for target '_module_/var/lib/dkms/rtlwifi-new/0.10/build' failed
make: *** [_module_/var/lib/dkms/rtlwifi-new/0.10/build] Error 2
make: Leaving directory '/usr/src/linux-headers-4.8.0-36-generic'

I can confirm that my wifi lan card is a Realtek RTL8723BE device since that is what my Windows OS recognizes it as and I have installed the Windows equivalent driver for it and it working fine there.

The output from modinfo rtl8723be is as follows-:

alex@alex-HP-Notebook:~/Desktop/rtlwifi_new-master$ modinfo rtl8723be
filename:       /lib/modules/4.8.0-36-generic/kernel/drivers/net/wireless/realtek/rtlwifi/rtl8723be/rtl8723be.ko
firmware:       rtlwifi/rtl8723befw.bin
description:    Realtek 8723BE 802.11n PCI wireless
license:        GPL
author:         Realtek WlanFAE <[email protected]>
author:         PageHe  <[email protected]>
srcversion:     1520FD8B69687790125304A
alias:          pci:v000010ECd0000B723sv*sd*bc*sc*i*
depends:        rtlwifi,rtl8723-common,rtl_pci,btcoexist,mac80211
intree:         Y
vermagic:       4.8.0-36-generic SMP mod_unload modversions 
parm:           swenc:Set to 1 for software crypto (default 0)
 (bool)
parm:           ips:Set to 0 to not use link power save (default 1)
 (bool)
parm:           swlps:Set to 1 to use SW control power save (default 0)
 (bool)
parm:           fwlps:Set to 1 to use FW control power save (default 1)
 (bool)
parm:           msi:Set to 1 to use MSI interrupts mode (default 0)
 (bool)
parm:           debug:Set debug level (0-5) (default 0) (int)
parm:           disable_watchdog:Set to 1 to disable the watchdog (default 0)
 (bool)
parm:           ant_sel:Set to 1 or 2 to force antenna number (default 0)

Also my router is configured with the following parameters-:

Wireless Band: 2.4 GHz
802.11 Mode: Mixed 802.11n, 802.11g, 802.11b
Auto Channel Scan enabled
Wireless Channel : 2.437 GHz - CH 6
Channel Width: Auto 20/40 MHz
networking

4 Answers

  1. Best Answer

    Quite often, the weak signal is a symptom of the antenna wire being connected to connection #1 on the card when the default driver is expecting to see the signal at connection #2. Of course, you could open the laptop and switch the wire or you could instruct the driver to explicitly select the working antenna connection. First, try connection #1:

    sudo -i
echo "options rtl8723be ant_sel=1"  >  /etc/modprobe.d/rtl8723be.conf
exit

    Reboot and test. If this is ineffective, try #2:

    sudo -i
echo "options rtl8723be ant_sel=2"  >  /etc/modprobe.d/rtl8723be.conf
exit
    • 2

  2. The 4.8 or 4.10 kernel doesn't require the rtkwifi-new module. You need to uninstall it.

    Run

    sudo apt purge rtlwifi-new-dkms
sudo add-apt-repository -r ppa:hanipouspilot/rtlwifi

    Then use this answer to fix the weak signal issue.

    • 1

  3. The code you are trying to compile is likely for a kernel version less than 4.7. This is the specific commit where those enums got removed.

    In the source code for the driver you could try this as a quick fix.

    #define IEEE80211_BAND_2GHZ NL80211_BAND_2GHZ 
#define IEEE80211_BAND_5GHZ NL80211_BAND_5GHZ 
#define ieee80211_band nl80211_band
#define IEEE80211_NUM_BANDS NUM_NL80211_BANDS
    • 1

  4. Have you checked your wifi signal strength? I suggest you to use wifi scanner https://www.netspotapp.com/wireless-network-wifi-scanner.html to monitor your network and identify problem areas first. I think the problem can be in the level of background noise at your house.

    • 0