lenovo e540 RTL8723be wifi not working

Question

I'm really struggling to have working wifi on my laptop lenovo E540. I googled about my network card using ubuntu, but nothing solved my problem.
First of all, I installed Ubuntu 14.04.1 LTS 64-bit. I could use wifi, but after few minutes it would turn off and I could not connect to wifi again. So I started googling.
lspci:

Network controller: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter

First of all, I found this thread with comment 29 to be helpful for many users having same controller as me. So I installed it and got kernel panic. I googled more. Found kozak127's edited rtl8723be. Tried it, got kernel panic.
Here is suggested to use older kernel. No differece there for me. My kernel:

3.13.0-35-generic

So my question is: Is there a way to get this realtek controller working? how?

Offtopic: I bought a new laptop, so I would have less problems than I had with lenovo n500 and ubuntu. Is there a brand that works great with linux? I looked up lenovo n540 and linux compatibility and no problems were reported there.

EDIT 1:

/etc/modprobe.d/rtl8723be.conf
/lib/modules/3.13.0-32-generic/kernel/drivers/net/wireless/rtlwifi/rtl8723be
/lib/modules/3.13.0-32-generic/kernel/drivers/net/wireless/rtlwifi/rtl8723be/rtl8723be.ko
/usr/src/linux-headers-3.13.0-32/drivers/net/wireless/rtlwifi/rtl8723be
/usr/src/linux-headers-3.13.0-32/drivers/net/wireless/rtlwifi/rtl8723be/Makefile
/usr/src/linux-headers-3.13.0-32-generic/include/config/rtl8723be.h
/usr/src/linux-headers-3.13.0-35/drivers/net/wireless/rtlwifi/rtl8723be
/usr/src/linux-headers-3.13.0-35/drivers/net/wireless/rtlwifi/rtl8723be/Makefile
/usr/src/linux-headers-3.13.0-35-generic/include/config/rtl8723be.h

Solution 1

The system natively includes the driver rtl8723be. We need to troubleshoot the native driver. Before we do so, please uninstall the two drivers you installed that caused kernel panics. Follow the process you followed previously for both, except instead of make and sudo make install, do sudo make uninstall.

Then do:

gksudo gedit /etc/modprobe.d/blacklist.conf

Use nano or kate or leafpad if you don't have the text editor gedit. Remove the line: blacklist rtl8723be. Proofread carefully, save and close the text editor.

Now do:

sudo modprobe rtl8723be swenc=1
sudo iwconfig wlan0 power off

Is your wireless working better now? If so, we'll amend a couple of files and make it permanent.

It appears that, somehow, the rtl8723be was deleted in the process of trying two replacements that failed by causing kernel panics. Let's try to reinstall the current linux-image. With a working internet connection:

sudo apt-get install --reinstall linux-image-$(uname -r)

After it's done, retry the steps above.

Solution 2

I've resolved that on my Lenovo Flex2 with Ubuntu 14.10, installing the new driver from https://github.com/lwfinger/rtlwifi_new. It seems to have solved my problems, don't forget to reboot Ubuntu.

Procedure:

After to unzip that run the following command to install the new drive

$: make $: sudo make install

reboot the OS.

note: we've to run the same procedure every time we want to upgrade our Ubuntu with a new kernel

note2: in Ubuntu 15.04 is not necessary to make that

Comments

[chili555]

Did you uninstall both the packages that caused a kernel panic? Is there any clue here? dmesg | grep rtl Thanks.

[Lucas03]

I blacklisted them. I can not uninstall if it is blacklisted :( Should I run apt-get purge or something like that? dmesg | grep returns nothing, because it blacklisted. I don't see wifi option in my panel with that driver blacklisted.

[Lucas03]

thanks, I uninstalled both drivers. No kernel panic now. But now I'm missing rtl8723be driver. modprobe: FATAL: Module rtl8723be not found.. How do I install it?

[chili555]

If you are running 14.04.1, it should be present by default. Let's see if we can locate it: sudo updatedb This will take a few moments, please be patient. Then: locate rtl8723be.ko In my case, among others: /lib/modules/3.13.0-35-generic/kernel/drivers/net/wireless/r‌​tlwifi/rtl8723be/rtl‌​8723be.ko

[chili555]

And is 3.13.0-32 the kernel you are running right now? uname -r Do you have temporary ethernet or other connectivity so you can update?

[Lucas03]

no, i'm running 3.13.0-35-generic.

[chili555]

Please see my edit above.

[Lucas03]

after that reinstall I run locale rtl8723be and only on same kernel version was found :(

[chili555]

Did you first: sudo updatedb? What about sudo modprobe rtl8723be?

[Lucas03]

Let us continue this discussion in chat.

[Teaqu]

Still not working on 3.16 for me.

[Eugene van der Merwe]

This worked for me on Linux Mint Rebecca. When I looked, the driver file was updated 19 days ago, thus 23 Feb 2015. One small note, after make install some permission errors, but sudo make install seems to do rest of work.