rtl8812au-dkms 4.3.8.12175.20140902+dfsg-0ubuntu2: rtl8812au kernel module failed to build [error: implicit declaration of function ‘is_compat_task’]

[Lin David]

The wifi driver not worked.

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: rtl8812au-dkms 4.3.8.12175.20140902+dfsg-0ubuntu2
Uname: Linux 4.6.5-040605-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
DKMSKernelVersion: 4.4.0-45-generic
Date: Sat Oct 22 15:55:54 2016
DuplicateSignature: dkms:rtl8812au-dkms:4.3.8.12175.20140902+dfsg-0ubuntu2:/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/os_dep/linux/rtw_android.c:577:6: error: implicit declaration of function ‘is_compat_task’ [-Werror=implicit-function-declaration]
PackageArchitecture: all
PackageVersion: 4.3.8.12175.20140902+dfsg-0ubuntu2
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.1
 apt 1.2.12~ubuntu16.04.1
SourcePackage: rtl8812au
Title: rtl8812au-dkms 4.3.8.12175.20140902+dfsg-0ubuntu2: rtl8812au kernel module failed to build
UpgradeStatus: Upgraded to xenial on 2016-08-01 (86 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Hendrik Schrieber (hennekn)]

Also affects linux kernel version 4.8 which is used as hwe for xenial.

[Julio Lajara (ju2wheels)]

Can confirm, I have the same issue.

As a temporary fix (I couldnt find where CONFIG_COMPAT was defined in the 4.4 lts xenial kernel in 16.04.1), I added the following to the very top of /usr/src/rtl8812au-4.3.8.12175.20140902+dfsg/os_dep/linux/rtw_android.c :

```
# Note: This not a correct general purpose solution but for building on amd64 16.04.2 it works fine.

#ifdef CONFIG_COMPAT
#undef CONFIG_COMPAT
#endif

```

This allowed me to build the driver on amd64 16.04.2, followed by the following:

```
sudo dkms remove -m rtl8812au/4.3.8.12175.20140902+dfsg --all
sudo dkms install -m rtl8812au -v 4.3.8.12175.20140902+dfsg
sudo modprobe -r 8812au
sudo modprobe 8812au
# unplug/replug the usb device
sudo systemctl restart NetworkManager
```

The driver will now work with the 4.8 HWE kernel on 16.04.2 and so far the networking in general seems far more stable than with the xenial kernel.

[Brendan (brendan-rankin)]

What is the purpose of CONFIG_COMPAT? Regardless, it's clearly broken here!

[Kenneth Westervelt (gimmickless)]

It looks like this change to the Linux kernel caused the break. Not knowing the purpose or scope of COMPAT, it's hard to say what it was meant to improve.

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5180e3e24fd3e8e7ea46fbe21e10f5ea3fb1edaa

[Hannu Teulahti (teu)]

This version seems to work. Maybe there is some pointers how to fix this.

https://github.com/abperiasamy/rtl8812AU_8821AU_linux

[TJ (tj)]

This minor patch fixed the build for me.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "Patch for kernel 4.4+ using in_compat_syscall() instead of is_compat_task()" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

[TJ (tj)]

I found that this driver does NOT support some USB devices based on the 8821au (since the Debian/Ubuntu source lacks some HAL files) and USB device IDs.

In my case:
$ lsusb

Bus 001 Device 109: ID 0bda:0811 Realtek Semiconductor Corp.

I found a working driver (based on later (4.3.14) upstream source) that can also be built and installed via DKMS at:

https://github.com/abperiasamy/rtl8812AU_8821AU_linux

which builds the module rtl8812au.ko

[CedS (tumeprendslechou)]

Same problem for me on Ubuntu 16.04.3 with 4.10.0-37 generic kernel,
when following these steps, the wifi device is working, but it break at each kernel upgrade :

https://blog.danielscrivano.com/installing-rtl8812au-on-linux-for-wireless-dual-band-usb-adapters/

Waiting for a fix in the official repository :/

[Ken Wagner (beaucoder)]

Package will not successfully install: sudo apt install rtl8812au-dkms

Is there a workaround that does not require constantly re-installing after an upgrade?

Thank you.

[Ken Wagner (beaucoder)]

Followed https://blog.danielscrivano.com/installing-rtl8812au-on-linux-for-wireless-dual-band-usb-adapters/

sudo modprobe 8812au Does not work. Fatal error.

instead copy 8812au.ko to /lib/modules/4.10.0-38-generic
(On my computer).

Then it worked. Will keep an eye on it after updates and upgrades.

HTH.

Cheers,
Ken

[Nils Toedtmann (m-launchpad-net-mail-nils-toedtmann-net)]

Same here on Ubuntu 16.04:

$ sudo apt-get install rtl8812au-dkms
#...
Building for 4.10.0-40-generic and 4.10.0-42-generic
Building initial module for 4.10.0-40-generic
Error! Bad return status for module build on kernel: 4.10.0-40-generic (x86_64)
Consult /var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/make.log for more information.

$ cat /var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/make.logDKMS make.log for rtl8812au-4.3.8.12175.20140902+dfsg for kernel 4.10.0-40-generic (x86_64)
Tue Dec 12 08:43:46 EST 2017
make ARCH=x86_64 CROSS_COMPILE= -C /lib/modules/4.10.0-40-generic/build M=/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build modules
# ...
/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/os_dep/linux/rtw_android.c: In function ‘rtw_android_priv_cmd’:
/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/os_dep/linux/rtw_android.c:577:6: error: implicit declaration of function ‘is_compat_task’ [-Werror=implicit-function-declaration]
  if (is_compat_task()) {
      ^
cc1: some warnings being treated as errors
scripts/Makefile.build:294: recipe for target '/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/os_dep/linux/rtw_android.o' failed
make[2]: *** [/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build/os_dep/linux/rtw_android.o] Error 1
Makefile:1524: recipe for target '_module_/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build' failed
make[1]: *** [_module_/var/lib/dkms/rtl8812au/4.3.8.12175.20140902+dfsg/build] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-4.10.0-40-generic'
Makefile:1459: recipe for target 'modules' failed
make: *** [modules] Error 2

$ uname -a
Linux dlogicvt 4.10.0-40-generic #44~16.04.1-Ubuntu SMP Thu Nov 9 15:37:44 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

$ sudo lsusb
#...
Bus 003 Device 003: ID 0bda:a811 Realtek Semiconductor Corp.

[Julio Lajara (ju2wheels)]

Seems this broke again with the 4.13.0 HWE kernel on 16.04 . Now, in addition to the patch I described above for CONFIG_COMPAT, you also need the following patch to /usr/src/rtl8812au-4.3.8.12175.20140902+dfsg/include/osdep_service_linux.h :

```
#ifndef __OSDEP_LINUX_SERVICE_H_
#define __OSDEP_LINUX_SERVICE_H_

        #include <linux/version.h>
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,11,0))
        #include <linux/sched/signal.h>
#endif
        #include <linux/spinlock.h>
```

This patch includes a conditional for the kernel schedule signal headers for newer kernels. You can then follow the same steps at the end of my previous comment to recompile the driver.