iwlwifi: mvm: wait for stop sched-scan completion

cfg80211 assumes a scheduled scan is stopped synchronously. Wait for the
FW before returning to caller.

Don't do anything in the async handler in the stop-from-above flow.
There's no need to call the mac80211 sched-scan completion as the
cleanup will be automatic. Make sure the async handler is called before
the next incoming scan changes the scan_status by flushing the async
handlers after all invocations.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

3 files changed, 46 insertions, 27 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
index 41b9e65f6a3f..fff66ab2cfda 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
@@ -1419,8 +1419,6 @@ static int iwl_mvm_mac_hw_scan(struct ieee80211_hw *hw,
                                struct cfg80211_scan_request *req)
 {
         struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
-        struct iwl_notification_wait wait_scan_done;
-        static const u8 scan_done_notif[] = { SCAN_OFFLOAD_COMPLETE, };
         int ret;
 
         if (req->n_channels == 0 || req->n_channels > MAX_NUM_SCAN_CHANNELS)
@@ -1430,22 +1428,11 @@ static int iwl_mvm_mac_hw_scan(struct ieee80211_hw *hw,
 
         switch (mvm->scan_status) {
         case IWL_MVM_SCAN_SCHED:
-                iwl_init_notification_wait(&mvm->notif_wait, &wait_scan_done,
-                                           scan_done_notif,
-                                           ARRAY_SIZE(scan_done_notif),
-                                           NULL, NULL);
-                iwl_mvm_sched_scan_stop(mvm);
-                ret = iwl_wait_notification(&mvm->notif_wait,
-                                            &wait_scan_done, HZ);
+                ret = iwl_mvm_sched_scan_stop(mvm);
                 if (ret) {
                         ret = -EBUSY;
                         goto out;
                 }
-                /* iwl_mvm_rx_scan_offload_complete_notif() will be called
-                 * soon but will not reset the scan status as it won't be
-                 * IWL_MVM_SCAN_SCHED any more since we queue the next scan
-                 * immediately (below)
-                 */
                 break;
         case IWL_MVM_SCAN_NONE:
                 break;
@@ -1461,7 +1448,8 @@ static int iwl_mvm_mac_hw_scan(struct ieee80211_hw *hw,
                 iwl_mvm_unref(mvm, IWL_MVM_REF_SCAN);
 out:
         mutex_unlock(&mvm->mutex);
-
+        /* make sure to flush the Rx handler before the next scan arrives */
+        iwl_mvm_wait_for_async_handlers(mvm);
         return ret;
 }
 
@@ -1751,12 +1739,14 @@ static int iwl_mvm_mac_sched_scan_stop(struct ieee80211_hw *hw,
                                        struct ieee80211_vif *vif)
 {
         struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
+        int ret;
 
         mutex_lock(&mvm->mutex);
-        iwl_mvm_sched_scan_stop(mvm);
+        ret = iwl_mvm_sched_scan_stop(mvm);
         mutex_unlock(&mvm->mutex);
+        iwl_mvm_wait_for_async_handlers(mvm);
 
-        return 0;
+        return ret;
 }
 
 static int iwl_mvm_mac_set_key(struct ieee80211_hw *hw,
diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index 3511bf79abcd..4da53c395ad3 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h
@@ -712,6 +712,11 @@ static inline const char *iwl_mvm_get_tx_fail_reason(u32 status) { return ""; }
 int iwl_mvm_flush_tx_path(struct iwl_mvm *mvm, u32 tfd_msk, bool sync);
 void iwl_mvm_async_handlers_purge(struct iwl_mvm *mvm);
 
+static inline void iwl_mvm_wait_for_async_handlers(struct iwl_mvm *mvm)
+{
+        flush_work(&mvm->async_handlers_wk);
+}
+
 /* Statistics */
 int iwl_mvm_rx_reply_statistics(struct iwl_mvm *mvm,
                                 struct iwl_rx_cmd_buffer *rxb,
@@ -813,7 +818,7 @@ int iwl_mvm_config_sched_scan_profiles(struct iwl_mvm *mvm,
                                        struct cfg80211_sched_scan_request *req);
 int iwl_mvm_sched_scan_start(struct iwl_mvm *mvm,
                              struct cfg80211_sched_scan_request *req);
-void iwl_mvm_sched_scan_stop(struct iwl_mvm *mvm);
+int iwl_mvm_sched_scan_stop(struct iwl_mvm *mvm);
 int iwl_mvm_rx_sched_scan_results(struct iwl_mvm *mvm,
                                   struct iwl_rx_cmd_buffer *rxb,
                                   struct iwl_device_cmd *cmd);
diff --git a/drivers/net/wireless/iwlwifi/mvm/scan.c b/drivers/net/wireless/iwlwifi/mvm/scan.c
index b4c9fb649976..a2cd54b57e67 100644
--- a/drivers/net/wireless/iwlwifi/mvm/scan.c
+++ b/drivers/net/wireless/iwlwifi/mvm/scan.c
@@ -519,10 +519,11 @@ int iwl_mvm_rx_scan_offload_complete_notif(struct iwl_mvm *mvm,
                        scan_notif->status == IWL_SCAN_OFFLOAD_COMPLETED ?
                        "completed" : "aborted");
 
-        /* might already be something else again, don't reset if so */
-        if (mvm->scan_status == IWL_MVM_SCAN_SCHED)
+        /* only call mac80211 completion if the stop was initiated by FW */
+        if (mvm->scan_status == IWL_MVM_SCAN_SCHED) {
                 mvm->scan_status = IWL_MVM_SCAN_NONE;
-        ieee80211_sched_scan_stopped(mvm->hw);
+                ieee80211_sched_scan_stopped(mvm->hw);
+        }
 
         return 0;
 }
@@ -894,26 +895,49 @@ static int iwl_mvm_send_sched_scan_abort(struct iwl_mvm *mvm)
                  * microcode has notified us that a scan is completed.
                  */
                 IWL_DEBUG_SCAN(mvm, "SCAN OFFLOAD ABORT ret %d.\n", status);
-                ret = -EIO;
+                ret = -ENOENT;
         }
 
         return ret;
 }
 
-void iwl_mvm_sched_scan_stop(struct iwl_mvm *mvm)
+int iwl_mvm_sched_scan_stop(struct iwl_mvm *mvm)
 {
         int ret;
+        struct iwl_notification_wait wait_scan_done;
+        static const u8 scan_done_notif[] = { SCAN_OFFLOAD_COMPLETE, };
 
         lockdep_assert_held(&mvm->mutex);
 
         if (mvm->scan_status != IWL_MVM_SCAN_SCHED) {
                 IWL_DEBUG_SCAN(mvm, "No offloaded scan to stop\n");
-                return;
+                return 0;
         }
 
+        iwl_init_notification_wait(&mvm->notif_wait, &wait_scan_done,
+                                   scan_done_notif,
+                                   ARRAY_SIZE(scan_done_notif),
+                                   NULL, NULL);
+
         ret = iwl_mvm_send_sched_scan_abort(mvm);
-        if (ret)
+        if (ret) {
                 IWL_DEBUG_SCAN(mvm, "Send stop offload scan failed %d\n", ret);
-        else
-                IWL_DEBUG_SCAN(mvm, "Successfully sent stop offload scan\n");
+                iwl_remove_notification(&mvm->notif_wait, &wait_scan_done);
+                return ret;
+        }
+
+        IWL_DEBUG_SCAN(mvm, "Successfully sent stop offload scan\n");
+
+        ret = iwl_wait_notification(&mvm->notif_wait, &wait_scan_done, 1 * HZ);
+        if (ret)
+                return ret;
+
+        /*
+         * Clear the scan status so the next scan requests will succeed. This
+         * also ensures the Rx handler doesn't do anything, as the scan was
+         * stopped from above.
+         */
+        mvm->scan_status = IWL_MVM_SCAN_NONE;
+
+        return 0;
 }