mac80211: fix idle handling sequence

Corey Richardson reported that my idle handling cleanup
(commit fd0f979a1b, "mac80211: simplify idle handling")
broke ath9k_htc. The reason appears to be that it wants
to go out of idle before switching channels. To fix it,
reimplement that sequence.

Reported-by: Corey Richardson <corey@octayn.net>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 16 insertions, 4 deletions

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 78c0d90dd641..931be419ab5a 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -63,6 +63,7 @@ ieee80211_new_chanctx(struct ieee80211_local *local,
                       enum ieee80211_chanctx_mode mode)
 {
         struct ieee80211_chanctx *ctx;
+        u32 changed;
         int err;
 
         lockdep_assert_held(&local->chanctx_mtx);
@@ -76,6 +77,13 @@ ieee80211_new_chanctx(struct ieee80211_local *local,
         ctx->conf.rx_chains_dynamic = 1;
         ctx->mode = mode;
 
+        /* acquire mutex to prevent idle from changing */
+        mutex_lock(&local->mtx);
+        /* turn idle off *before* setting channel -- some drivers need that */
+        changed = ieee80211_idle_off(local);
+        if (changed)
+                ieee80211_hw_config(local, changed);
+
         if (!local->use_chanctx) {
                 local->_oper_channel_type =
                         cfg80211_get_chandef_type(chandef);
@@ -85,14 +93,17 @@ ieee80211_new_chanctx(struct ieee80211_local *local,
                 err = drv_add_chanctx(local, ctx);
                 if (err) {
                         kfree(ctx);
-                        return ERR_PTR(err);
+                        ctx = ERR_PTR(err);
+
+                        ieee80211_recalc_idle(local);
+                        goto out;
                 }
         }
 
+        /* and keep the mutex held until the new chanctx is on the list */
         list_add_rcu(&ctx->list, &local->chanctx_list);
 
-        mutex_lock(&local->mtx);
-        ieee80211_recalc_idle(local);
+ out:
         mutex_unlock(&local->mtx);
 
         return ctx;
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 7bdefd901f9d..5672533a0832 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1362,6 +1362,7 @@ int ieee80211_if_change_type(struct ieee80211_sub_if_data *sdata,
                              enum nl80211_iftype type);
 void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata);
 void ieee80211_remove_interfaces(struct ieee80211_local *local);
+u32 ieee80211_idle_off(struct ieee80211_local *local);
 void ieee80211_recalc_idle(struct ieee80211_local *local);
 void ieee80211_adjust_monitor_flags(struct ieee80211_sub_if_data *sdata,
                                     const int offset);
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 3bfe2612c8c2..58150f877ec3 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -78,7 +78,7 @@ void ieee80211_recalc_txpower(struct ieee80211_sub_if_data *sdata)
                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_TXPOWER);
 }
 
-static u32 ieee80211_idle_off(struct ieee80211_local *local)
+u32 ieee80211_idle_off(struct ieee80211_local *local)
 {
         if (!(local->hw.conf.flags & IEEE80211_CONF_IDLE))
                 return 0;