Subject: [PATCH] mac80211: introduce set_radar_offchan callback
From: Lorenzo Bianconi <[email-masked]>
Date: Sat, 23 Oct 2021 11:10:51 +0200

Similar to cfg80211, introduce set_radar_offchan callback in mac80211_ops
in order to configure a dedicated offchannel chain available on some hw
(e.g. mt7915) to perform offchannel CAC detection and avoid tx/rx downtime.

Tested-by: Evelyn Tsai <[email-masked]>
Signed-off-by: Lorenzo Bianconi <[email-masked]>
Link: https://lore.kernel.org/r/[email-masked]
Signed-off-by: Johannes Berg <[email-masked]>
---

--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -3937,6 +3937,14 @@ struct ieee80211_prep_tx_info {
  *	twt structure.
  * @twt_teardown_request: Update the hw with TWT teardown request received
  *	from the peer.
+ * @set_radar_offchan: Configure dedicated offchannel chain available for
+ *	radar/CAC detection on some hw. This chain can't be used to transmit
+ *	or receive frames and it is bounded to a running wdev.
+ *	Offchannel radar/CAC detection allows to avoid the CAC downtime
+ *	switching to a different channel during CAC detection on the selected
+ *	radar channel.
+ *	The caller is expected to set chandef pointer to NULL in order to
+ *	disable offchannel CAC/radar detection.
  * @net_fill_forward_path: Called from .ndo_fill_forward_path in order to
  *	resolve a path for hardware flow offloading
  */
@@ -4267,6 +4275,8 @@ struct ieee80211_ops {
 			      struct ieee80211_twt_setup *twt);
 	void (*twt_teardown_request)(struct ieee80211_hw *hw,
 				     struct ieee80211_sta *sta, u8 flowid);
+	int (*set_radar_offchan)(struct ieee80211_hw *hw,
+				 struct cfg80211_chan_def *chandef);
 #if LINUX_VERSION_IS_GEQ(5,10,0)
 	int (*net_fill_forward_path)(struct ieee80211_hw *hw,
 				     struct ieee80211_vif *vif,
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -4344,6 +4344,18 @@ out:
 	return err;
 }
 
+static int
+ieee80211_set_radar_offchan(struct wiphy *wiphy,
+			    struct cfg80211_chan_def *chandef)
+{
+	struct ieee80211_local *local = wiphy_priv(wiphy);
+
+	if (!local->ops->set_radar_offchan)
+		return -EOPNOTSUPP;
+
+	return local->ops->set_radar_offchan(&local->hw, chandef);
+}
+
 const struct cfg80211_ops mac80211_config_ops = {
 	.add_virtual_intf = ieee80211_add_iface,
 	.del_virtual_intf = ieee80211_del_iface,
@@ -4448,4 +4460,5 @@ const struct cfg80211_ops mac80211_confi
 	.reset_tid_config = ieee80211_reset_tid_config,
 	.set_sar_specs = ieee80211_set_sar_specs,
 	.color_change = ieee80211_color_change,
+	.set_radar_offchan = ieee80211_set_radar_offchan,
 };