在京东上给家里的台式机(DELL OPTIPLEX 380)买了一个腾达（Tenda）U12 1300M USB无线网卡，遗憾的是腾达官方的U12网卡驱动无法直接使用，因为其支持的Linux内核最大版本为4.4。那就自己想办法编译吧，本文接下来就介绍如何在Ubuntu16.04(32位内核)上编译并安装这一网卡驱动。

腾达(U12)USB无线网卡Linux驱动安装笔记-冯金伟博客园

00 – 系统信息

$ cat /etc/*release | grep VERSION=
VERSION="16.04.6 LTS (Xenial Xerus)"
$ uname -rp
4.15.0-88-generic i686

01 – 尝试编译腾达官方提供的rtl8812au驱动

$ wget https://down.tenda.com.cn/uploadfile/U12/U12_linux_v5.1.5_19247_Driver.zip
$ unzip U12_linux_v5.1.5_19247_Driver.zip 
$ cd U12_linux_v5.1.5_19247.20160830/driver
$ tar zxf rtl8812AU_linux_v5.1.5_19247.20160830.tar.gz 
$ cd rtl8812AU_linux_v5.1.5_19247.20160830/
$ make
make ARCH=i386 CROSS_COMPILE= -C /lib/modules/4.15.0-88-generic/build M=/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830  modules
make[1]: Entering directory '/usr/src/linux-headers-4.15.0-88-generic'
  CC [M]  /tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/core/rtw_cmd.o
In file included from /tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service.h:41:0,
                 from /tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/drv_types.h:32,
                 from /tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/core/rtw_cmd.c:22:
/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service_linux.h: In function ‘_init_timer’:
/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service_linux.h:273:8: error: ‘_timer {aka struct timer_list}’ has no member named ‘data’
  ptimer->data = (unsigned long)cntx;
        ^
/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service_linux.h:274:2: error: implicit declaration of function ‘init_timer’ [-Werror=implicit-function-declaration]
  init_timer(ptimer);
  ^
In file included from /tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/drv_types.h:32:0,
                 from /tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/core/rtw_cmd.c:22:
/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service.h: In function ‘thread_enter’:
/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service.h:345:2: error: implicit declaration of function ‘allow_signal’ [-Werror=implicit-function-declaration]
  allow_signal(SIGTERM);
  ^
/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service.h: In function ‘flush_signals_thread’:
/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service.h:355:6: error: implicit declaration of function ‘signal_pending’ [-Werror=implicit-function-declaration]
  if (signal_pending(current))
      ^
/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service.h:356:3: error: implicit declaration of function ‘flush_signals’ [-Werror=implicit-function-declaration]
   flush_signals(current);
   ^
cc1: some warnings being treated as errors
scripts/Makefile.build:330: recipe for target '/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/core/rtw_cmd.o' failed
make[2]: *** [/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/core/rtw_cmd.o] Error 1
Makefile:1577: recipe for target '_module_/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830' failed
make[1]: *** [_module_/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-4.15.0-88-generic'
Makefile:1838: recipe for target 'modules' failed
make: *** [modules] Error 2

尝试修改了一些编译错误，例如：

--- /tmp/osdep_service_linux.h
+++ /tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service_linux.h
@@ -57,6 +57,7 @@
 #include <linux/kthread.h>
 #include <linux/list.h>
 #include <linux/vmalloc.h>
+#include <linux/sched/signal.h>
 
 #if (LINUX_VERSION_CODE <= KERNEL_VERSION(2, 5, 41))
     #include <linux/tqueue.h>
@@ -270,7 +271,7 @@
 {
     /* setup_timer(ptimer, pfunc,(u32)cntx);     */
     ptimer->function = pfunc;
-    ptimer->data = (unsigned long)cntx;
+    ptimer->expires = (unsigned long)cntx;
     init_timer(ptimer);
 }

但是, init_timer(ptimer)的问题一时半会儿解决不了，

make ARCH=i386 CROSS_COMPILE= -C /lib/modules/4.15.0-88-generic/build M=/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830  modules
make[1]: Entering directory '/usr/src/linux-headers-4.15.0-88-generic'
  CC [M]  /tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/core/rtw_cmd.o
In file included from /tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service.h:41:0,
                 from /tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/drv_types.h:32,
                 from /tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/core/rtw_cmd.c:22:
/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service_linux.h: In function ‘_init_timer’:
/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/include/osdep_service_linux.h:275:2: error: implicit declaration of function ‘init_timer’ [-Werror=implicit-function-declaration]
  init_timer(ptimer);
  ^
cc1: some warnings being treated as errors
scripts/Makefile.build:330: recipe for target '/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/core/rtw_cmd.o' failed
make[2]: *** [/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830/core/rtw_cmd.o] Error 1
Makefile:1577: recipe for target '_module_/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830' failed
make[1]: *** [_module_/tmp/U12_linux_v5.1.5_19247.20160830/driver/rtl8812AU_linux_v5.1.5_19247.20160830] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-4.15.0-88-generic'
Makefile:1838: recipe for target 'modules' failed
make: *** [modules] Error 2

于是果断放弃这一”自己造轮子“的思路！

02 – 搜索现成的解决方案

使用关键字”rtl8812au” + “github”进行google搜索，

腾达(U12)USB无线网卡Linux驱动安装笔记-冯金伟博客园

果然找到了一个GitHub的repo, Realtek 802.11n WLAN Adapter Linux driver! 既然有人做了对应的修复，那就站在巨人的肩膀上，直接拿来用吧。

$ git clone https://github.com/gnab/rtl8812au.git
$ cd rtl8812au
$ make
$ sudo make install

$ file /lib/modules/4.15.0-88-generic/kernel/drivers/net/wireless/8812au.ko
/lib/modules/4.15.0-88-generic/kernel/drivers/net/wireless/8812au.ko: ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), BuildID[sha1]=4be6be46e28f1bdd558f472dda7d35c86d435ece, not stripped
$ modinfo /lib/modules/4.15.0-88-generic/kernel/drivers/net/wireless/8812au.ko
filename:       /lib/modules/4.15.0-88-generic/kernel/drivers/net/wireless/8812au.ko
version:        v4.2.3
author:         Realtek Semiconductor Corp.
description:    Realtek Wireless Lan Driver
license:        GPL
srcversion:     719F640400ECDE6A55AB3B9
alias:          usb:v0BDAp0823d*dc*dsc*dp*ic*isc*ip*in*
...<snip>..............................................
name:           8812au
vermagic:       4.15.0-88-generic SMP mod_unload 686 
parm:           rtw_ips_mode:The default IPS mode (int)
...<snip>..............................................
parm:           rtw_led_enable:Enable status LED (int)

$ sudo modprobe 8812au
$ sudo lsmod | egrep 8812au
    8812au                856064  0

连接wifi成功上网，网卡状态如下：

$ ethinfo enx502b73d14b1b
ETH             MAC               STATE DEVICEID VENDORID MTU  SPEED BDF     DRIVER                IPv4            
enx502b73d14b1b 50:2b:73:d1:4b:1b up                      1500       1-5:1.0 usb/drivers/rtl8812au 192.168.3.9/24

大功告成！Have  fun:-)

03 – 小结

做研究/写论文时，找不到相关文献往往只有两种可能：

没有选择合适的关键字(keywords)；
所提的问题没有意义，没有人做。

科研如此，解决日常生活及工作中遇到的问题也如此。之所以果断放弃自己修复rtl8812au驱动代码的方案，是因为：

首先，”自己发明轮子”的难度较大，时间成本太高；
其次，这个问题有价值，Linux内核不断迭代，rtl8812au既然没有被停产，那其驱动的升级维护就一定有同行在干或已经干成了。

果然一搜就有现成的代码，那就愉快地站在巨人的肩膀上have fun吧:-)

扩展阅读

Writing Network Device Drivers for Linux