Linux does not see Alfa AWUS036NHA. “firmware: failed to load ath9k_htc” error (SOLVED)

When connecting a Wi-Fi adapter based on the Atheros chipset, such as Alfa AWUS036NHA, a Linux computer does not see the Wi-Fi device. Command

iw dev

does not output anything, as if the device is not connected.

In the Linux Wi-Fi Cheat Sheet: Tips and Troubleshooting, we'll use the advice from the “How to ask a question about a problem with a Wi-Fi adapter” section, namely, open several terminal windows and run the following commands in them:

iw event
ip monitor
journalctl -f

Then plug the Wi-Fi adapter to the computer.

journalctl gave the following messages:

Jan 27 00:55:28 HackWare-Kali kernel: usb 1-1: ath9k_htc: Firmware ath9k_htc/htc_9271-1.4.0.fw requested
Jan 27 00:55:28 HackWare-Kali kernel: usb 1-1: firmware: failed to load ath9k_htc/htc_9271-1.4.0.fw (-2)
Jan 27 00:55:28 HackWare-Kali kernel: usb 1-1: Direct firmware load for ath9k_htc/htc_9271-1.4.0.fw failed with error -2
Jan 27 00:55:28 HackWare-Kali kernel: usb 1-1: ath9k_htc: Firmware htc_9271.fw requested
Jan 27 00:55:28 HackWare-Kali kernel: usb 1-1: firmware: failed to load htc_9271.fw (-2)
Jan 27 00:55:28 HackWare-Kali kernel: usb 1-1: Direct firmware load for htc_9271.fw failed with error -2
Jan 27 00:55:28 HackWare-Kali kernel: usb 1-1: no suitable firmware found!
Jan 27 00:55:28 HackWare-Kali kernel: usb 1-1: ath9k_htc: USB layer deinitialized

The key to solving the problem in these messages is the information that the ath9k_htc firmware is not loaded. For devices to work, in addition to the driver (which can be part of the kernel or installed separately), firmware is required.

Let's search for the firmware:

apt search ath9k_htc

In Kali Linux, the ath9k_htc firmware is placed in a separate firmware-atheros package, install it:

sudo apt install firmware-atheros

On Debian, Ubuntu and Linux Mint, run the following command to install:

sudo apt firmware-ath9k-htc

On Arch Linux, Manjaro, BlackArch and their derivatives, run the command:

sudo pacman -S linux-firmware

After installing the firmware and restarting the computer, the problem will disappear and the Wi-Fi adapter will work.