RTL8192CU

• problem: on Linux, TP-LINK TL-WN821N (chip rtl8192c) disappears from network
  • solution: (source: https://github.com/pvaret/rtl8192cu-fixes/blob/master/8192cu-disable-power-management.conf)

create /etc/modprobe.d/8192cu-disable-power-management.conf with the code below:

# Disable power management in the 8192cu driver. This works around a bug in
# some hardware where the device never wakes back up.
# Credit goes to Saqib Razaq (https://github.com/s-razaq) for the fix.

# rtw_power_mgnt=0 disables power saving
# rtw_enusbss=0 disables USB autosuspend
options 8192cu rtw_power_mgnt=0 rtw_enusbss=0