@alzhao - you are right when I was trying to make mine EDIMAX dongle work I had applied the rtl-sdr_2013-06-12_ar71xx.ipk and librtlsdr_2013-06-12_ar71xx.ipk may be that made my AR9271 work - but after your email I reset the router and I had to apply kmod-ath9k-htc and reboot before AR9271 would work again.
When I applied the kmod-ath9k-htc package I did get errors
on every single script of sub packages I get similar error
Collected errors: * pkg_run_script: package “ath9k-htc-firmware” postinst script returned status 255. * opkg_configure: ath9k-htc-firmware.postinst returned 255. *
but after reboot AR9271 is working .