DFS 開啟

1:

$ iw reg get
country 00: DFS-UNSET
https://wireless.wiki.kernel.org/en/developers/regulatory/crda
git clone git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-regdb.git
cp -rf wireless-regdb/db.txt linux-kernel/net/wireless/db.txt
在kernel 的config 開啟
CONFIG_CFG80211_INTERNAL_REGDB=y
重新編譯kernel,
iw reg set US
iw reg get
這時候會發現
console:/ # iw reg get
global
country US: DFS-FCC
        (2402 - 2472 @ 40), (N/A, 30), (N/A)
        (5170 - 5250 @ 80), (N/A, 17), (N/A), AUTO-BW
        (5250 - 5330 @ 80), (N/A, 23), (0 ms), DFS, AUTO-BW
        (5735 - 5835 @ 80), (N/A, 30), (N/A)
        (57240 - 63720 @ 2160), (N/A, 40), (N/A)