UPDATE - 2018-02-01: I was informed by @nmccrina that the repo linked to in this post is no longer maintained. Please use https://github.com/paspro/rtl8812au instead.
NOTE: Most of the content from this post comes from a blog post I found that concentrated on getting the driver set up on Fedora 21. I did mostly the same steps with a few tweaks.
Intro
Driver support for 802.11ac in Linux is spotty especially if you are using a USB adapter. I picked up the NetGear A6100 that has the Realtek RTL8811AU chip inside of it. Of course, when I plug it in I can see the device, but no support in the kernel I'm using (kernel-4.2.8-200.fc22.x86_64).
On my system I currently have the built in wireless adapter, as well as the USB plugged in. From the output below you can see only one wireless NIC shows up:
# lspci | grep Network 00:19.0 Ethernet controller: Intel Corporation 82579LM Gigabit Network Connection (rev 04) 03:00.0 Network controller: Intel Corporation Centrino Ultimate-N 6300 (rev 3e) $ lsusb | grep NetGear Bus 001 Device 002: ID 0846:9052 NetGear, Inc. A6100 AC600 DB Wireless Adapter [Realtek RTL8811AU] # ip -o link | grep wlp | cut -d ' ' -f 2 wlp3s0:
The wlp3s0 is my built in wifi device.
The Realtek Driver
You can find the Realtek driver for the RTL8811AU at a couple of the sites for the many vendors that incorporate the chip:
- Archer T4UH
- D-Link DWA-182
These drivers often vary in version and often don't compile on newer kernels, which can be frustrating when you just want something to work.
Getting The RTL8811AU Driver Working
Luckily some people in the community unofficially manage code repositories with fixes to the Realtek driver to allow it to compile on newer kernels. From the blog post I mentioned earlier there is a linked GitHub repository where the Realtek driver is reproduced with some patches on top. This repository makes it pretty easy to get set up and get the USB adapters working on Linux.
NOTE: In case the git repo moves in the future I have copied an archive of it here for posterity. The commit id at head at the time of this use is 9fc227c2987f23a6b2eeedf222526973ed7a9d63.
The first step is to set up your system for DKMS to make it so that you don't have to recompile the kernel module every time you install a new kernel. To do this install the following packages and set the dkms service to start on boot:
# dnf install -y dkms kernel-devel-$(uname -r) # systemctl enable dkms
Next, clone the git repository and observe the version of the driver:
# mkdir /tmp/rtldriver && cd /tmp/rtldriver # git clone https://github.com/Grawp/rtl8812au_rtl8821au.git # cat rtl8812au_rtl8821au/include/rtw_version.h #define DRIVERVERSION "v4.3.14_13455.20150212_BTCOEX20150128-51" #define BTCOEXVERSION "BTCOEX20150128-51"
From the output we can see this is the 4.3.14_13455.20150212 version of the driver, which is fairly recent.
Next let's create a directory under /usr/src for the source code to live and copy it into place:
# mkdir /usr/src/8812au-4.3.14_13455.20150212 # cp -R ./rtl8812au_rtl8821au/* /usr/src/8812au-4.3.14_13455.20150212/
Next we'll create a dkms.conf file which will tell DKMS how to manage building this module when builds/installs are requested; run man dkms to view more information on these settings:
# cat <<'EOF' > /usr/src/8812au-4.3.14_13455.20150212/dkms.conf
PACKAGE_NAME="8812au"
PACKAGE_VERSION="4.3.14_13455.20150212"
BUILT_MODULE_NAME[0]="8812au"
DEST_MODULE_LOCATION[0]="/kernel/drivers/net/wireless"
AUTOINSTALL="yes"
MAKE[0]="'make' all KVER=${kernelver}"
CLEAN="'make' clean"
EOF
Note one change from the earlier blog post, which is that I include KVER=${kernelver} in the make line. If you don't do this then the Makefile will incorrectly detect the kernel by calling uname, which is wrong when run during a new kernel installation because the new kernel is not yet running. If we didn't do this then every time a new kernel was installed the driver would get compiled for the previous kernel (the one that was running at the time of installation).
The next step is to add the module to the DKMS system and go ahead and build it:
# dkms add -m 8812au -v 4.3.14_13455.20150212
Creating symlink /var/lib/dkms/8812au/4.3.14_13455.20150212/source ->
/usr/src/8812au-4.3.14_13455.20150212
DKMS: add completed.
# dkms build -m 8812au -v 4.3.14_13455.20150212
Kernel preparation unnecessary for this kernel. Skipping...
Building module:
cleaning build area...
'make' all KVER=4.2.8-200.fc22.x86_64......................
cleaning build area...
DKMS: build completed.
And finally install it:
# dkms install -m 8812au -v 4.3.14_13455.20150212 8812au: Running module version sanity check. - Original module - No original module exists within this kernel - Installation - Installing to /lib/modules/4.2.8-200.fc22.x86_64/extra/ Adding any weak-modules depmod.... DKMS: install completed.
Now we can load the module and see information about it:
# modprobe 8812au # modinfo 8812au | head -n 3 filename: /lib/modules/4.2.8-200.fc22.x86_64/extra/8812au.ko version: v4.3.14_13455.20150212_BTCOEX20150128-51 author: Realtek Semiconductor Corp.
Does the wireless NIC work now? After connecting to an AC only network here are the results:
# ip -o link | grep wlp | cut -d ' ' -f 2
wlp3s0:
wlp0s20u2:
# iwconfig wlp0s20u2
wlp0s20u2 IEEE 802.11AC ESSID:"random" Nickname:"<WIFI@REALTEK>"
Mode:Managed Frequency:5.26 GHz Access Point: A8:BB:B7:EE:B6:8D
Bit Rate:87 Mb/s Sensitivity:0/0
Retry:off RTS thr:off Fragment thr:off
Encryption key:****-****-****-****-****-****-****-**** Security mode:open
Power Management:off
Link Quality=95/100 Signal level=100/100 Noise level=0/100
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
Sweet!!
Keeping it Working After Kernel Updates
Let's test out to see if updating a kernel leaves us with a system that has an updated driver or not. Before the kernel update:
# tree /var/lib/dkms/8812au/4.3.14_13455.20150212/ /var/lib/dkms/8812au/4.3.14_13455.20150212/ ├── 4.2.8-200.fc22.x86_64 │ └── x86_64 │ ├── log │ │ └── make.log │ └── module │ └── 8812au.ko └── source -> /usr/src/8812au-4.3.14_13455.20150212 5 directories, 2 files
Now the kernel update and viewing it after:
# dnf -y update kernel kernel-devel --enablerepo=updates-testing ... Installed: kernel.x86_64 4.3.3-200.fc22 kernel-core.x86_64 4.3.3-200.fc22 kernel-devel.x86_64 4.3.3-200.fc22 kernel-modules.x86_64 4.3.3-200.fc22 Complete! # tree /var/lib/dkms/8812au/4.3.14_13455.20150212/ /var/lib/dkms/8812au/4.3.14_13455.20150212/ ├── 4.2.8-200.fc22.x86_64 │ └── x86_64 │ ├── log │ │ └── make.log │ └── module │ └── 8812au.ko ├── 4.3.3-200.fc22.x86_64 │ └── x86_64 │ ├── log │ │ └── make.log │ └── module │ └── 8812au.ko └── source -> /usr/src/8812au-4.3.14_13455.20150212 9 directories, 4 files
And from the log we can verify that the module was built against the right kernel:
# head -n 4 /var/lib/dkms/8812au/4.3.14_13455.20150212/4.3.3-200.fc22.x86_64/x86_64/log/make.log DKMS make.log for 8812au-4.3.14_13455.20150212 for kernel 4.3.3-200.fc22.x86_64 (x86_64) Sun Jan 24 19:40:51 EST 2016 make ARCH=x86_64 CROSS_COMPILE= -C /lib/modules/4.3.3-200.fc22.x86_64/build M=/var/lib/dkms/8812au/4.3.14_13455.20150212/build modules make[1]: Entering directory '/usr/src/kernels/4.3.3-200.fc22.x86_64'
Success!