Realtek RTL8191SU Wireless Not Working w/ Grinch 21.3.4

I’ve recently flashed to L4T R21.4, and my USB wifi adapter (RTL8191SU-based) has stopped working.

I believe I am using the latest grinch kernel (details below). The USB device is listed, it appears the correct kernel module is loaded (r8712u), but nmcli does not display the device.

Have any of you come across something similar?

ubuntu@tegra-ubuntu:~$ head -n 1 /etc/nv_tegra_release
# R21 (release), REVISION: 4.0, GCID: 5650832, BOARD: ardbeg, EABI: hard, DATE: Thu Jun 25 22:38:59 UTC 2015

ubuntu@tegra-ubuntu:~$ uname -a
Linux tegra-ubuntu 3.10.40-grinch-21.3.4 #1 SMP PREEMPT Fri May 1 10:41:09 UTC 2015 armv7l armv7l armv7l GNU/Linux

ubuntu@tegra-ubuntu:~$ lsusb
Bus 002 Device 002: ID 0bda:8172 Realtek Semiconductor Corp. RTL8191SU 802.11n WLAN Adapter
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

ubuntu@tegra-ubuntu:~$ lsmod
Module                  Size  Used by
dm_crypt               12216  0 
dm_mod                 67166  1 dm_crypt
r8712u                156323  0 
bnep                    9804  2 
rtc_as3722              3709  0 
rfcomm                 33654  0 
bluetooth             279634  10 bnep,rfcomm
rfkill                  9587  3 bluetooth
parport_pc             28514  0 
lp                      8097  0 
parport                27466  2 lp,parport_pc
nvhost_vi               2874  0 
nfsd                  237014  0 

ubuntu@tegra-ubuntu:~$ nmcli dev
DEVICE     TYPE              STATE        
eth0       802-3-ethernet    unavailable

I’m not familiar with the particular adapter, but if wireless is involved there was probably a firmware file to also install along with the new kernel.

Rookie mistake! Installing the Ubuntu firmware package solved the problem…

apt-get install linux-firmware

I should have noticed the missing firmware error in the dmesg output.