wifi: mac80211: use wiphy_hrtimer_work for CAC timeout

Prior initiating communication in a DFS channel, there should be a
monitoring of RADAR in that channel for a minimum of 600 seconds if it
is a Weather RADAR channel and 60 seconds for other DFS channels. This
Channel Availability Check(CAC) is currently implemented by scheduling
a work item for execution with a delay equal to an appropriate timeout.
But this work item is observed to take more delay than specified
(4-5 seconds in regular DFS channels and 25-30 seconds in Weather RADAR
channels). Even though this delay is expected in case of delayed work
queue as there is no guarantee that the work will be scheduled exactly
after the specified delay, a delay of more than 20 seconds is too much
for the AP to be in non-operational state.

Recently commit 7ceba45a6658 ("wifi: cfg80211: add an hrtimer based
delayed work item") added an infrastructure to overcome this issue by
supporting high resolution timers for mac80211 delayed work, which do not
have this timeout latency. Switch the CAC timeout to use this
infrastructure, so the CAC completion handling is triggered with tighter
timing and reduced latency.

Signed-off-by: Amith A <amith.a@oss.qualcomm.com>
Link: https://patch.msgid.link/20260130035511.2328713-1-amith.a@oss.qualcomm.com
[fix delay handling]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

5 files changed, 9 insertions, 9 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 964f440e31cd..3551049d64b3 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1916,7 +1916,7 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev,
 
 	if (sdata->wdev.links[link_id].cac_started) {
 		chandef = link_conf->chanreq.oper;
-		wiphy_delayed_work_cancel(wiphy, &link->dfs_cac_timer_work);
+		wiphy_hrtimer_work_cancel(wiphy, &link->dfs_cac_timer_work);
 		cfg80211_cac_event(sdata->dev, &chandef,
 				   NL80211_RADAR_CAC_ABORTED,
 				   GFP_KERNEL, link_id);
@@ -3874,8 +3874,8 @@ static int ieee80211_start_radar_detection(struct wiphy *wiphy,
 	if (err)
 		return err;
 
-	wiphy_delayed_work_queue(wiphy, &link_data->dfs_cac_timer_work,
-				 msecs_to_jiffies(cac_time_ms));
+	wiphy_hrtimer_work_queue(wiphy, &link_data->dfs_cac_timer_work,
+				 ms_to_ktime(cac_time_ms));
 
 	return 0;
 }
@@ -3894,7 +3894,7 @@ static void ieee80211_end_cac(struct wiphy *wiphy,
 		if (!link_data)
 			continue;
 
-		wiphy_delayed_work_cancel(wiphy,
+		wiphy_hrtimer_work_cancel(wiphy,
 					  &link_data->dfs_cac_timer_work);
 
 		if (sdata->wdev.links[link_id].cac_started) {
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index ea4c9293d299..e9e3b7f60ff5 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1099,7 +1099,7 @@ struct ieee80211_link_data {
 	int ap_power_level; /* in dBm */
 
 	bool radar_required;
-	struct wiphy_delayed_work dfs_cac_timer_work;
+	struct wiphy_hrtimer_work dfs_cac_timer_work;
 
 	union {
 		struct ieee80211_link_data_managed mgd;
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 463b78093d3e..5dfe605b37d4 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -565,7 +565,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, bool going_do
 	wiphy_work_cancel(local->hw.wiphy, &sdata->deflink.csa.finalize_work);
 	wiphy_work_cancel(local->hw.wiphy,
 			  &sdata->deflink.color_change_finalize_work);
-	wiphy_delayed_work_cancel(local->hw.wiphy,
+	wiphy_hrtimer_work_cancel(local->hw.wiphy,
 				  &sdata->deflink.dfs_cac_timer_work);
 
 	if (sdata->wdev.links[0].cac_started) {
diff --git a/net/mac80211/link.c b/net/mac80211/link.c
index 1e05845872af..17bf55dabd31 100644
--- a/net/mac80211/link.c
+++ b/net/mac80211/link.c
@@ -116,7 +116,7 @@ void ieee80211_link_init(struct ieee80211_sub_if_data *sdata,
 			ieee80211_color_change_finalize_work);
 	wiphy_delayed_work_init(&link->color_collision_detect_work,
 				ieee80211_color_collision_detection_work);
-	wiphy_delayed_work_init(&link->dfs_cac_timer_work,
+	wiphy_hrtimer_work_init(&link->dfs_cac_timer_work,
 				ieee80211_dfs_cac_timer_work);
 
 	if (!deflink) {
@@ -155,7 +155,7 @@ void ieee80211_link_stop(struct ieee80211_link_data *link)
 			  &link->csa.finalize_work);
 
 	if (link->sdata->wdev.links[link->link_id].cac_started) {
-		wiphy_delayed_work_cancel(link->sdata->local->hw.wiphy,
+		wiphy_hrtimer_work_cancel(link->sdata->local->hw.wiphy,
 					  &link->dfs_cac_timer_work);
 		cfg80211_cac_event(link->sdata->dev,
 				   &link->conf->chanreq.oper,
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 4d5680da7aa0..260893b83df1 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -3597,7 +3597,7 @@ void ieee80211_dfs_cac_cancel(struct ieee80211_local *local,
 			if (ctx && &ctx->conf != chanctx_conf)
 				continue;
 
-			wiphy_delayed_work_cancel(local->hw.wiphy,
+			wiphy_hrtimer_work_cancel(local->hw.wiphy,
 						  &link->dfs_cac_timer_work);
 
 			if (!sdata->wdev.links[link_id].cac_started)