mac80211: add pre_channel_switch driver operation

Some drivers may need to prepare for a channel switch also when it is
initiated from the remote side (eg. station, P2P client).  To make
this possible, add a generic callback that can be called for all
interface types.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 17 insertions, 8 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index f2e048fa250c..d23d6d97e453 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1057,6 +1057,7 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
         struct ieee80211_chanctx *chanctx;
         enum ieee80211_band current_band;
         struct ieee80211_csa_ie csa_ie;
+        struct ieee80211_channel_switch ch_switch;
         int res;
 
         sdata_assert_lock(sdata);
@@ -1128,6 +1129,22 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
                 }
         }
 
+        ch_switch.timestamp = timestamp;
+        ch_switch.device_timestamp = device_timestamp;
+        ch_switch.block_tx = csa_ie.mode;
+        ch_switch.chandef = csa_ie.chandef;
+        ch_switch.count = csa_ie.count;
+
+        if (drv_pre_channel_switch(sdata, &ch_switch)) {
+                sdata_info(sdata,
+                           "preparing for channel switch failed, disconnecting\n");
+                ieee80211_queue_work(&local->hw,
+                                     &ifmgd->csa_connection_drop_work);
+                mutex_unlock(&local->chanctx_mtx);
+                mutex_unlock(&local->mtx);
+                return;
+        }
+
         res = ieee80211_vif_reserve_chanctx(sdata, &csa_ie.chandef,
                                             chanctx->mode, false);
         if (res) {
@@ -1153,14 +1170,6 @@ ieee80211_sta_process_chanswitch(struct ieee80211_sub_if_data *sdata,
 
         if (local->ops->channel_switch) {
                 /* use driver's channel switch callback */
-                struct ieee80211_channel_switch ch_switch = {
-                        .timestamp = timestamp,
-                        .device_timestamp = device_timestamp,
-                        .block_tx = csa_ie.mode,
-                        .chandef = csa_ie.chandef,
-                        .count = csa_ie.count,
-                };
-
                 drv_channel_switch(local, &ch_switch);
                 return;
         }