The PCI-Express card TP-Link TL-WDN4800 has the PCI ID 168c:0030. The card bases on the Atheros chipset AR9380 and is recognized by the Linux kernel (e.g. Ubuntu 12.10) in the following way:
20:00.0 Network controller: Atheros Communications Inc. AR9300 Wireless LAN adaptor (rev 01)
Subsystem: Atheros Communications Inc. Device [168c:3112]
The card is fully supported by the kernel module ath9k. If an older version of the driver is used the connection can show a very low bandwidth. In this case it is necessary to disable the hardware encryption of the WiFi chipset to allow a higher data throughput. To achieve this the Kernel module ath9k has to be loaded with an additional option, which can be set in the file /etc/modprobe.d/ath9k.conf:
options ath9k nohwcrypt=1
The kernel module ath9k is loaded automatically:
ath: EEPROM regdomain: 0x21
ath: EEPROM indicates we should expect a direct regpair map
ath: Country alpha2 being used: AU
ath: Regpair used: 0x21
ieee80211 phy0: Selected rate control algorithm 'ath9k_rate_control'
ath: EEPROM regdomain: 0x809c
ath: EEPROM indicates we should expect a country code
ath: doing EEPROM country->regdmn map search
ath: country maps to regdmn code: 0x52
ath: Country alpha2 being used: CN
ath: Regpair used: 0x52
ieee80211 phy1: Selected rate control algorithm 'ath9k_rate_control'
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