Atheros AR9271

Topics in this section,

• Learnings in this section

• Atheros Wi-Fi driver image

• Atheros AR9271 features

• Version Info

• Steps to load atheros wifi driver

  • STEP 1: Check wifi chipset

  • STEP 2: Check dmesg output

  • STEP 3: Stop existing Wireless Modules

  • STEP 4: Compile Linux

  • STEP 5: Compile Wireless Modules

  • STEP 6: Check for “.ko” files

  • STEP 7: Check for “.zst” file, if present remove that file

  • STEP 8: Restart your system

  • STEP 9: Change directory to compiled kernel path

  • STEP 10: Clear old kernel logs

  • STEP 11: Insert the modules

  • STEP 12: Check the loaded modules

  • STEP 13: Check the interface name

  • STEP 14: Let us do Wireless driver development !

    • STEP 14.1: Init path debugging

      • Add prints in module init, module exit

    • STEP 14.2: Control path debugging

      • Add prints in nl80211_small_ops

      • Add prints in mac80211_config_ops

      • Add prints in ath9k_htc_ops

    • STEP 14.3: Data path debugging

      • Add prints in ieee80211_dataif_ops

Wi-Fi Atheros Driver

• In this section, you are going to learn

• How to load atheros wifi linux driver for Atheros AR9271 802.11n USB Wi-Fi Adapter

Atheros AR9271 802.11n USB Wi-Fi Adapter

Atheros AR9271 802.11n USB Wi-Fi Adapter features

Features
Hardware Interface	USB 2.0
Compatible Devices	Laptop, Desktop
Data Link Protocol	USB
Data Transfer Rate	150 Megabits Per Second
Item Weight	0.03 Kilograms

Version Info

#	Version
Ubuntu	Ubuntu 22.04 64 bit
Linux Kernel	6.9.0
Wifi chip	Atheros
Chipset version	Atheros AR9271

Steps to load Atheros wifi driver

STEP 1: Check wifi chipset

• Insert the wifi usb adapter to the usb port:

• Check the wifi chipset by running the below command

test:~$ lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 413c:301a Dell Computer Corp. Dell MS116 Optical Mouse
Bus 001 Device 004: ID 0cf3:9271 Qualcomm Atheros Communications AR9271 802.11n
Bus 001 Device 002: ID 0461:0010 Primax Electronics, Ltd HP PR1101U / Primax PMX-KPR1101U Keyboard
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

STEP 2: Check dmesg output

• Check the dmesg output by running the below command:

test:~$ sudo dmesg
[15075.422501] usb 1-5: new high-speed USB device number 7 using xhci_hcd
[15075.587285] usb 1-5: New USB device found, idVendor=0cf3, idProduct=9271, bcdDevice= 1.08
[15075.587298] usb 1-5: New USB device strings: Mfr=16, Product=32, SerialNumber=48
[15075.587303] usb 1-5: Product: UB93
[15075.587308] usb 1-5: Manufacturer: ATHEROS
[15075.587311] usb 1-5: SerialNumber: 12345

STEP 3: Stop existing Wireless Modules

• Stop applications by running the commands below:

test@test-V520-15IKL:~/linux-6.9$ pwd
/home/test/linux-6.9

test:~/linux-6.9$ sudo systemctl stop NetworkManager.service

test:~/linux-6.9$ sudo killall wpa_supplicant hostapd

test:~/linux-6.9$ ps -N | grep -i wpa_supplicant

test:~/linux-6.9$ ps -N | grep -i hostapd

• Run lsmod commands:

test:~/linux-6.9$ lsmod | grep -i mac80211
mac80211             1712128  1 ath9k_htc
libarc4                12288  3 lib80211_crypt_tkip,lib80211_crypt_wep,mac80211
cfg80211             1376256  4 ath9k_htc,ath9k_common,ath,mac80211

test:~/linux-6.9$ lsmod | grep -i lib80211
lib80211_crypt_tkip    24576  0
lib80211_crypt_ccmp    16384  0
lib80211_crypt_wep     12288  0
libarc4                12288  3 lib80211_crypt_tkip,lib80211_crypt_wep,mac80211
lib80211               16384  3 lib80211_crypt_tkip,lib80211_crypt_wep,lib80211_crypt_ccmp

test:~/linux-6.9$ lsmod | grep -i ath
ath9k_htc             114688  0
ath9k_common           49152  1 ath9k_htc
ath9k_hw              659456  2 ath9k_htc,ath9k_common
ath                    36864  3 ath9k_htc,ath9k_common,ath9k_hw
mac80211             1712128  1 ath9k_htc
cfg80211             1376256  4 ath9k_htc,ath9k_common,ath,mac80211

• Now, remove drivers by executing rmmod command as shown below:

test@test-V520-15IKL:~/linux-6.9$ sudo rmmod ath9k_htc
test@test-V520-15IKL:~/linux-6.9$ sudo rmmod ath9k_common
test@test-V520-15IKL:~/linux-6.9$ sudo rmmod ath9k_hw
test@test-V520-15IKL:~/linux-6.9$ sudo rmmod ath
test@test-V520-15IKL:~/linux-6.9$ sudo rmmod mac80211
test@test-V520-15IKL:~/linux-6.9$ sudo rmmod lib80211_crypt_tkip
test@test-V520-15IKL:~/linux-6.9$ sudo rmmod lib80211_crypt_ccmp
test@test-V520-15IKL:~/linux-6.9$ sudo rmmod lib80211_crypt_wep
test@test-V520-15IKL:~/linux-6.9$ sudo rmmod libarc4
test@test-V520-15IKL:~/linux-6.9$ sudo rmmod lib80211
test@test-V520-15IKL:~/linux-6.9$ sudo rmmod cfg80211

STEP 4: Compile Linux

• Follow steps from the link : <https://c-pointers.com/osp/bare_linux/x86-64/secB.html>

• Move to compiled Linux folder as shown below:

$ cd /home/test/linux-6.9

STEP 5: Compile Wireless Modules

• Check current directory:

test@test-V520-15IKL:~/linux-6.9$ pwd
/home/test/linux-6.9

• Start compilation for wireless folder:

test@test-V520-15IKL:~/linux-6.9$ sudo make -C . M=net/wireless/
make: Entering directory "/home/test/linux-6.9"
  CC [M]  net/wireless/core.o
  LD [M]  net/wireless/cfg80211.o
  CC [M]  net/wireless/lib80211.o
  CC [M]  net/wireless/lib80211_crypt_wep.o
  CC [M]  net/wireless/lib80211_crypt_ccmp.o
  CC [M]  net/wireless/lib80211_crypt_tkip.o
  MODPOST net/wireless/Module.symvers
  LD [M]  net/wireless/cfg80211.ko
  LD [M]  net/wireless/lib80211.ko
  LD [M]  net/wireless/lib80211_crypt_wep.ko
  LD [M]  net/wireless/lib80211_crypt_ccmp.ko
  LD [M]  net/wireless/lib80211_crypt_tkip.ko
make: Leaving directory "/home/test/linux-6.9"

• Run make command for mac80211 folder:

test@test-V520-15IKL:~/linux-6.9$ sudo make -C . M=net/mac80211
make: Entering directory "/home/test/linux-6.9"
  CC [M]  net/mac80211/main.o
  LD [M]  net/mac80211/mac80211.o
  MODPOST net/mac80211/Module.symvers
  LD [M]  net/mac80211/mac80211.ko
make: Leaving directory "/home/test/linux-6.9"

• Run make command for ath folder:

test@test-V520-15IKL:~/linux-6.9$ sudo make -C . M=drivers/net/wireless/ath/
make: Entering directory "/home/test/linux-6.9"
  MODPOST drivers/net/wireless/ath/Module.symvers
  CC [M]  drivers/net/wireless/ath/ath5k/ath5k.mod.o
  LD [M]  drivers/net/wireless/ath/ath5k/ath5k.ko
  CC [M]  drivers/net/wireless/ath/ath9k/ath9k.mod.o
  LD [M]  drivers/net/wireless/ath/ath9k/ath9k.ko
  CC [M]  drivers/net/wireless/ath/ath9k/ath9k_hw.mod.o
  LD [M]  drivers/net/wireless/ath/ath9k/ath9k_hw.ko
  CC [M]  drivers/net/wireless/ath/ath9k/ath9k_common.mod.o
  LD [M]  drivers/net/wireless/ath/ath9k/ath9k_common.ko
  CC [M]  drivers/net/wireless/ath/ath9k/ath9k_htc.mod.o
  LD [M]  drivers/net/wireless/ath/ath9k/ath9k_htc.ko
  CC [M]  drivers/net/wireless/ath/ath9k/ath9k_pci_owl_loader.mod.o
  LD [M]  drivers/net/wireless/ath/ath9k/ath9k_pci_owl_loader.ko
  CC [M]  drivers/net/wireless/ath/carl9170/carl9170.mod.o
  LD [M]  drivers/net/wireless/ath/carl9170/carl9170.ko
  CC [M]  drivers/net/wireless/ath/ath6kl/ath6kl_core.mod.o
  LD [M]  drivers/net/wireless/ath/ath6kl/ath6kl_core.ko
  CC [M]  drivers/net/wireless/ath/ath6kl/ath6kl_sdio.mod.o
  LD [M]  drivers/net/wireless/ath/ath6kl/ath6kl_sdio.ko
  CC [M]  drivers/net/wireless/ath/ath6kl/ath6kl_usb.mod.o
  LD [M]  drivers/net/wireless/ath/ath6kl/ath6kl_usb.ko
  CC [M]  drivers/net/wireless/ath/ar5523/ar5523.mod.o
  LD [M]  drivers/net/wireless/ath/ar5523/ar5523.ko
  CC [M]  drivers/net/wireless/ath/wil6210/wil6210.mod.o
  LD [M]  drivers/net/wireless/ath/wil6210/wil6210.ko
  CC [M]  drivers/net/wireless/ath/ath10k/ath10k_core.mod.o
  LD [M]  drivers/net/wireless/ath/ath10k/ath10k_core.ko
  CC [M]  drivers/net/wireless/ath/ath10k/ath10k_pci.mod.o
  LD [M]  drivers/net/wireless/ath/ath10k/ath10k_pci.ko
  CC [M]  drivers/net/wireless/ath/ath10k/ath10k_sdio.mod.o
  LD [M]  drivers/net/wireless/ath/ath10k/ath10k_sdio.ko
  CC [M]  drivers/net/wireless/ath/ath10k/ath10k_usb.mod.o
  LD [M]  drivers/net/wireless/ath/ath10k/ath10k_usb.ko
  CC [M]  drivers/net/wireless/ath/wcn36xx/wcn36xx.mod.o
  LD [M]  drivers/net/wireless/ath/wcn36xx/wcn36xx.ko
  CC [M]  drivers/net/wireless/ath/ath11k/ath11k.mod.o
  LD [M]  drivers/net/wireless/ath/ath11k/ath11k.ko
  CC [M]  drivers/net/wireless/ath/ath11k/ath11k_ahb.mod.o
  LD [M]  drivers/net/wireless/ath/ath11k/ath11k_ahb.ko
  CC [M]  drivers/net/wireless/ath/ath11k/ath11k_pci.mod.o
  LD [M]  drivers/net/wireless/ath/ath11k/ath11k_pci.ko
  CC [M]  drivers/net/wireless/ath/ath12k/ath12k.mod.o
  LD [M]  drivers/net/wireless/ath/ath12k/ath12k.ko
  CC [M]  drivers/net/wireless/ath/ath.mod.o
  LD [M]  drivers/net/wireless/ath/ath.ko
make: Leaving directory "/home/test/linux-6.9"

STEP 6: Check for “.ko” files

• Run find command to search for “.ko” files in ./net/wireless directory:

test@test-V520-15IKL:~/linux-6.9$ find ./net/wireless/ -iname "*.ko" -print
./net/wireless/lib80211_crypt_wep.ko
./net/wireless/cfg80211.ko
./net/wireless/lib80211_crypt_ccmp.ko
./net/wireless/lib80211.ko
./net/wireless/lib80211_crypt_tkip.ko

• Run find command to search for “.ko” files in ./net/mac80211 directory:

test@test-V520-15IKL:~/linux-6.9$ find ./net/mac80211/ -iname "*.ko" -print
./net/mac80211/mac80211.ko

• Run find command to search for “.ko” files in ./drivers/net/wireless/ath directory:

test@test-V520-15IKL:~/linux-6.9$ find ./drivers/net/wireless/ath/ -iname "*.ko" -print
./drivers/net/wireless/ath/ath10k/ath10k_pci.ko
./drivers/net/wireless/ath/ath10k/ath10k_core.ko
./drivers/net/wireless/ath/ath10k/ath10k_sdio.ko
./drivers/net/wireless/ath/ath10k/ath10k_usb.ko
./drivers/net/wireless/ath/ath12k/ath12k.ko
./drivers/net/wireless/ath/wil6210/wil6210.ko
./drivers/net/wireless/ath/ath11k/ath11k.ko
./drivers/net/wireless/ath/ath11k/ath11k_ahb.ko
./drivers/net/wireless/ath/ath11k/ath11k_pci.ko
./drivers/net/wireless/ath/wcn36xx/wcn36xx.ko
./drivers/net/wireless/ath/ath9k/ath9k_hw.ko
./drivers/net/wireless/ath/ath9k/ath9k_htc.ko
./drivers/net/wireless/ath/ath9k/ath9k.ko
./drivers/net/wireless/ath/ath9k/ath9k_pci_owl_loader.ko
./drivers/net/wireless/ath/ath9k/ath9k_common.ko
./drivers/net/wireless/ath/ar5523/ar5523.ko
./drivers/net/wireless/ath/ath6kl/ath6kl_sdio.ko
./drivers/net/wireless/ath/ath6kl/ath6kl_usb.ko
./drivers/net/wireless/ath/ath6kl/ath6kl_core.ko
./drivers/net/wireless/ath/ath.ko
./drivers/net/wireless/ath/ath5k/ath5k.ko
./drivers/net/wireless/ath/carl9170/carl9170.ko

STEP 7: Check for “.zst” file, if present remove that file

• Remove the following .zst files

test@test-V520-15IKL:~/linux-6.9$ find  /lib/modules/6.9.0/kernel/net/wireless/ -iname "*.ko.zst*" -print
/lib/modules/6.9.0/kernel/net/wireless/lib80211_crypt_wep.ko.zst
/lib/modules/6.9.0/kernel/net/wireless/lib80211_crypt_ccmp.ko.zst
/lib/modules/6.9.0/kernel/net/wireless/lib80211.ko.zst
/lib/modules/6.9.0/kernel/net/wireless/cfg80211.ko.zst
/lib/modules/6.9.0/kernel/net/wireless/lib80211_crypt_tkip.ko.zst

test@test-V520-15IKL:~/linux-6.9$ find  /lib/modules/6.9.0/kernel/net/mac80211/ -iname "*.ko.zst*" -print
/lib/modules/6.9.0/kernel/net/mac80211/mac80211.ko.zst

test@test-V520-15IKL:~/linux-6.9$ find  /lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ -iname "*.ko.zst*" -print
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath10k/ath10k_core.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath10k/ath10k_usb.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath10k/ath10k_sdio.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath10k/ath10k_pci.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath12k/ath12k.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/wil6210/wil6210.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath11k/ath11k.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath11k/ath11k_ahb.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath11k/ath11k_pci.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/wcn36xx/wcn36xx.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath9k/ath9k.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath9k/ath9k_hw.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath9k/ath9k_pci_owl_loader.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath9k/ath9k_common.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath9k/ath9k_htc.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ar5523/ar5523.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath6kl/ath6kl_usb.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath6kl/ath6kl_sdio.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath6kl/ath6kl_core.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath5k/ath5k.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/carl9170/carl9170.ko.zst
/lib/modules/6.9.0/kernel/drivers/net/wireless/ath/ath.ko.zst

STEP 8: Restart your system

• You may restart your system using the command below:

$ reboot

STEP 9: Change directory to compiled kernel path

• Repeat Step 3

$ cd /home/test/linux-6.9

• Repeat Step 5

STEP 10: Clear old kernel logs

test@test-V520-15IKL:~/linux-6.9$ sudo dmesg -c

STEP 11: Insert the modules

sudo insmod ./net/wireless/cfg80211.ko
sudo insmod ./net/wireless/lib80211.ko
sudo insmod ./lib/crypto/libarc4.ko
sudo insmod ./net/wireless/lib80211_crypt_wep.ko
sudo insmod ./net/wireless/lib80211_crypt_ccmp.ko
sudo insmod ./net/wireless/lib80211_crypt_tkip.ko
sudo insmod ./net/mac80211/mac80211.ko
sudo insmod ./drivers/net/wireless/ath/ath.ko
sudo insmod ./drivers/net/wireless/ath/ath9k/ath9k_hw.ko
sudo insmod ./drivers/net/wireless/ath/ath9k/ath9k_common.ko
sudo insmod ./drivers/net/wireless/ath/ath9k/ath9k_htc.ko

STEP 12: Check the loaded modules

test@test-V520-15IKL:~/linux-6.9$ lsmod
Module                  Size  Used by
ath9k_htc             114688  0
ath9k_common           49152  1 ath9k_htc
ath9k_hw              659456  2 ath9k_htc,ath9k_common
ath                    36864  3 ath9k_htc,ath9k_common,ath9k_hw
mac80211             1712128  1 ath9k_htc
lib80211_crypt_tkip    24576  0
lib80211_crypt_ccmp    16384  0
lib80211_crypt_wep     12288  0
libarc4                12288  3 lib80211_crypt_tkip,lib80211_crypt_wep,mac80211
lib80211               16384  3 lib80211_crypt_tkip,lib80211_crypt_wep,lib80211_crypt_ccmp
cfg80211             1376256  4 ath9k_htc,ath9k_common,ath,mac80211

STEP 13: Check for Wi-Fi interface name

test@test-V520-15IKL:~/linux-6.9$ iwconfig
lo        no wireless extensions.

enp1s0    no wireless extensions.

wlxc01c3031bc56  IEEE 802.11  ESSID:off/any
          Mode:Managed  Access Point: Not-Associated   Tx-Power=off
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:off

STEP 14: Let us do Wireless driver development !

STEP 14.1: Init path debugging

Add prints in “module_init” and “module_exit” functions in files mentioned below

• Open below files with vim and add prints in module_init and module_exit fucntions:

test:linux-6.9$ pwd
/home/test/linux-6.9

./net/wireless/lib80211_crypt_wep.c
./net/wireless/lib80211.c
./net/wireless/lib80211_crypt_tkip.c
./net/wireless/lib80211_crypt_ccmp.c
./net/wireless/core.c
./net/mac80211/main.c
./drivers/net/wireless/ath/ath9k/htc_drv_init.c
./drivers/net/wireless/ath/ath9k/common.c

STEP 14.2: Control path debugging

Add prints in nl80211_small_ops

• Open nl80211.c file with vim, add prints in all .doit functions in nl80211_small_ops

test:linux-6.9/net/wireless$ vi nl80211.c
static const struct genl_small_ops nl80211_small_ops[] = {
        {
                .cmd = NL80211_CMD_SET_WIPHY,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = nl80211_set_wiphy,
                .flags = GENL_UNS_ADMIN_PERM,
        },
        {
                .cmd = NL80211_CMD_GET_INTERFACE,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = nl80211_get_interface,
                .dumpit = nl80211_dump_interface,
                /* can be retrieved by unprivileged users */
                .internal_flags = IFLAGS(NL80211_FLAG_NEED_WDEV),
        },
        {
                .cmd = NL80211_CMD_SET_INTERFACE,
                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
                .doit = nl80211_set_interface,
                .flags = GENL_UNS_ADMIN_PERM,
                .internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV |
                 NL80211_FLAG_NEED_RTNL),
        },

Add prints in mac80211_config_ops

• Open cfg.c file with vim, add prints in all functions in mac80211_config_ops

test:linux-6.9/net/mac80211$ vi cfg.c
const struct cfg80211_ops mac80211_config_ops = {
        .add_virtual_intf = ieee80211_add_iface,
        .del_virtual_intf = ieee80211_del_iface,
        .change_virtual_intf = ieee80211_change_iface,
        .start_p2p_device = ieee80211_start_p2p_device,
        .stop_p2p_device = ieee80211_stop_p2p_device,

Add prints in ath9k_htc_ops

• Open htc_drv_main.c file with vim, add prints in all functions in ath9k_htc_ops

test:linux-6.9/drivers/net/wireless/net/wireless/ath/ath9k$ vi htc_drv_main.c
struct ieee80211_ops ath9k_htc_ops = {
        .add_chanctx = ieee80211_emulate_add_chanctx,
        .remove_chanctx = ieee80211_emulate_remove_chanctx,
        .change_chanctx = ieee80211_emulate_change_chanctx,
        .switch_vif_chanctx = ieee80211_emulate_switch_vif_chanctx,
        .tx                 = ath9k_htc_tx,
        .wake_tx_queue      = ieee80211_handle_wake_tx_queue,
        .start              = ath9k_htc_start,
        .stop               = ath9k_htc_stop,
        .add_interface      = ath9k_htc_add_interface,
        .remove_interface   = ath9k_htc_remove_interface,

STEP 14.3: Data path debugging

Add prints in ieee80211_dataif_ops

• Open iface.c file with vim, add prints in all functions in ieee80211_dataif_ops

test:linux-6.9/net/mac80211$ vi ./iface.c
static const struct net_device_ops ieee80211_dataif_ops = {
        .ndo_open               = ieee80211_open,
        .ndo_stop               = ieee80211_stop,
        .ndo_uninit             = ieee80211_uninit,
        .ndo_start_xmit         = ieee80211_subif_start_xmit,
        .ndo_set_rx_mode        = ieee80211_set_multicast_list,
        .ndo_set_mac_address    = ieee80211_change_mac,
        .ndo_get_stats64        = ieee80211_get_stats64,
        .ndo_setup_tc           = ieee80211_netdev_setup_tc,
};