@@ -9987,6 +9987,8 @@ void cfg80211_ch_switch_notify(struct net_device *dev,
  * @link_id: the link ID for MLO, must be 0 for non-MLO
  * @count: the number of TBTTs until the channel switch happens
  * @quiet: whether or not immediate quiet was requested by the AP
+ * @mcst_tu: max channel switch time in TUs, 0 if the MCST element was not
+ *	present
  *
  * Inform the userspace about the channel switch that has just
  * started, so that it can take appropriate actions (eg. starting

@@ -9995,7 +9997,7 @@ void cfg80211_ch_switch_notify(struct net_device *dev,
 void cfg80211_ch_switch_started_notify(struct net_device *dev,
 				       struct cfg80211_chan_def *chandef,
 				       unsigned int link_id, u8 count,
-				       bool quiet);
+				       bool quiet, u32 mcst_tu);
 
 /**
  * ieee80211_operating_class_to_band - convert operating class to band

@@ -953,6 +953,10 @@
  *	after %NL80211_ATTR_CH_SWITCH_COUNT TBTT's.  The userspace may
  *	decide to react to this indication by requesting other
  *	interfaces to change channel as well.
+ *	%NL80211_ATTR_MAX_CH_SWITCH_TIME included in this command indicates the
+ *	AP's Max Channel Switch Time. Userspace can use this information to
+ *	decide whether to remain connected or disconnect before the AP moves to
+ *	the new channel.
  *
  * @NL80211_CMD_START_P2P_DEVICE: Start the given P2P Device, identified by
  *	its %NL80211_ATTR_WDEV identifier. It must have been created with

@@ -3165,6 +3169,12 @@ enum nl80211_commands {
  * @NL80211_ATTR_NPCA_PRIMARY_FREQ: NPCA primary channel (u32)
  * @NL80211_ATTR_NPCA_PUNCT_BITMAP: NPCA puncturing bitmap (u32)
  *
+ * @NL80211_ATTR_MAX_CH_SWITCH_TIME: u32 attribute carrying the Switch Time
+ *	field from the MCST (Max Channel Switch Time) element, indicating the
+ *	time delta between the time the last beacon is transmitted by the AP in
+ *	the current channel and the expected time of the first beacon
+ *	transmitted by the AP in the new channel, expressed in TUs.
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use

@@ -3762,6 +3772,7 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_NPCA_PRIMARY_FREQ,
 	NL80211_ATTR_NPCA_PUNCT_BITMAP,
+	NL80211_ATTR_MAX_CH_SWITCH_TIME,
 
 	/* add attributes here, update the policy in nl80211.c */
 

@@ -22290,7 +22290,8 @@ static void nl80211_ch_switch_notify(struct cfg80211_registered_device *rdev,
 				     struct cfg80211_chan_def *chandef,
 				     gfp_t gfp,
 				     enum nl80211_commands notif,
-				     u8 count, bool quiet)
+				     u8 count, bool quiet,
+				     u32 mcst_tu)
 {
 	struct wireless_dev *wdev = netdev->ieee80211_ptr;
 	struct sk_buff *msg;

@@ -22322,6 +22323,10 @@ static void nl80211_ch_switch_notify(struct cfg80211_registered_device *rdev,
 		if (quiet &&
 		    nla_put_flag(msg, NL80211_ATTR_CH_SWITCH_BLOCK_TX))
 			goto nla_put_failure;
+		if (mcst_tu && (wdev->iftype == NL80211_IFTYPE_STATION ||
+				wdev->iftype == NL80211_IFTYPE_P2P_CLIENT) &&
+		    nla_put_u32(msg, NL80211_ATTR_MAX_CH_SWITCH_TIME, mcst_tu))
+			goto nla_put_failure;
 	}
 
 	genlmsg_end(msg, hdr);

@@ -22374,7 +22379,7 @@ void cfg80211_ch_switch_notify(struct net_device *dev,
 	cfg80211_sched_dfs_chan_update(rdev);
 
 	nl80211_ch_switch_notify(rdev, dev, link_id, chandef, GFP_KERNEL,
-				 NL80211_CMD_CH_SWITCH_NOTIFY, 0, false);
+				 NL80211_CMD_CH_SWITCH_NOTIFY, 0, false, 0);
 }
 EXPORT_SYMBOL(cfg80211_ch_switch_notify);
 

@@ -22421,7 +22426,7 @@ EXPORT_SYMBOL(cfg80211_incumbent_signal_notify);
 void cfg80211_ch_switch_started_notify(struct net_device *dev,
 				       struct cfg80211_chan_def *chandef,
 				       unsigned int link_id, u8 count,
-				       bool quiet)
+				       bool quiet, u32 mcst_tu)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct wiphy *wiphy = wdev->wiphy;

@@ -22435,7 +22440,7 @@ void cfg80211_ch_switch_started_notify(struct net_device *dev,
 
 	nl80211_ch_switch_notify(rdev, dev, link_id, chandef, GFP_KERNEL,
 				 NL80211_CMD_CH_SWITCH_STARTED_NOTIFY,
-				 count, quiet);
+				 count, quiet, mcst_tu);
 }
 EXPORT_SYMBOL(cfg80211_ch_switch_started_notify);