TP-LINK TL-WN821Nv4

wireless

Ensure you have the necessary prerequisites installed:
sudo apt-get install linux-headers-generic build-essential dkms

Clone this repository:
git clone https://github.com/pvaret/rtl8192cu-fixes.git

Set it up as a DKMS module:
sudo dkms add ./rtl8192cu-fixes

Build and install it:
sudo dkms install 8192cu/1.9

Refresh the module list:
sudo depmod -a

Ensure the native (and broken) kernel driver is blacklisted:
sudo cp ./rtl8192cu-fixes/blacklist-native-rtl8192.conf /etc/modprobe.d/
And reboot. You're done.

Troubleshooting
There is a known issue with power management on some hardware. If your WiFi connection drops after a few minutes, install the following module setting file to disable power management in your WiFi interface:

sudo cp ./rtl8192cu-fixes/8192cu-disable-power-management.conf /etc/modprobe.d/
And then reboot.