From: David Bauer <mail@david-bauer.net>
Date: Sat, 4 Jul 2020 13:20:07 +0200
Subject: hostapd: enter DFS state if no available channel is found

Previously hostapd would not stop transmitting when a DFS event was
detected and no available channel to switch to was available.

Disable and re-enable the interface to enter DFS state. This way, TX
does not happen until the kernel notifies hostapd about the NOP
expiring.

Signed-off-by: David Bauer <mail@david-bauer.net>

diff --git a/package/network/services/hostapd/patches/800-dfs-enter-DFS-state-if-no-available-channel-is-found.patch b/package/network/services/hostapd/patches/800-dfs-enter-DFS-state-if-no-available-channel-is-found.patch
new file mode 100644
index 0000000000000000000000000000000000000000..59e903f06ae66208517c2d620b4cd128f41f25c1
--- /dev/null
+++ b/package/network/services/hostapd/patches/800-dfs-enter-DFS-state-if-no-available-channel-is-found.patch
@@ -0,0 +1,28 @@
+From cefc52e6b93731c713f1bba1cb5e7e92105b758b Mon Sep 17 00:00:00 2001
+From: David Bauer <mail@david-bauer.net>
+Date: Fri, 3 Jul 2020 23:00:34 +0200
+Subject: [PATCH] dfs: enter DFS state if no available channel is found
+
+Previously hostapd would not stop transmitting when a DFS event was
+detected and no available channel to switch to was available.
+
+Disable and re-enable the interface to enter DFS state. This way, TX
+does not happen until the kernel notifies hostapd about the NOP
+expiring.
+
+Signed-off-by: David Bauer <mail@david-bauer.net>
+---
+ src/ap/dfs.c | 11 +++++++++--
+ 1 file changed, 9 insertions(+), 2 deletions(-)
+
+--- a/src/ap/dfs.c
++++ b/src/ap/dfs.c
+@@ -930,6 +930,8 @@ static int hostapd_dfs_start_channel_swi
+ 			wpa_printf(MSG_INFO,
+ 				   "%s: no DFS channels left, waiting for NOP to finish",
+ 				   __func__);
++			hostapd_disable_iface(iface);
++			hostapd_enable_iface(iface);
+ 			return err;
+ 		}
+ 
