iwlwifi: mvm: convert scan_status to a bitmap

LMAC scans cannot handle more than one scan at a time, but UMAC scans
can.  To avoid confusion we should combine the states of these two
types of scans.  To do so, we need to support mutliple scans at the
same time for UMAC.

This commit changes the scan_status element from a single value to a
bitmask of running scan types for LMAC.  Later, we will modify UMAC
scans to use the same state bitmask.

Additionally, add stopping scan flags for scheduled and regular scans.
This makes it easier to differentiate and handle stop requests
triggered by the driver and spontaneous stops generated by the
firmware.
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/mvm/mac80211.c

@@ -1227,7 +1227,7 @@ static void iwl_mvm_restart_cleanup(struct iwl_mvm *mvm)
 
 	iwl_trans_stop_device(mvm->trans);
 
-	mvm->scan_status = IWL_MVM_SCAN_NONE;
+	mvm->scan_status = 0;
 	mvm->ps_disabled = false;
 	mvm->calibrating = false;
 
@@ -2374,28 +2374,30 @@ static void iwl_mvm_bss_info_changed(struct ieee80211_hw *hw,
 }
 
 static int iwl_mvm_cancel_scan_wait_notif(struct iwl_mvm *mvm,
-					  enum iwl_scan_status scan_type)
+					  unsigned int scan_type)
 {
 	int ret;
 	bool wait_for_handlers = false;
 
 	mutex_lock(&mvm->mutex);
 
-	if (mvm->scan_status != scan_type) {
+	if (!(mvm->scan_status & scan_type)) {
 		ret = 0;
 		/* make sure there are no pending notifications */
 		wait_for_handlers = true;
 		goto out;
 	}
 
+	/* It's okay to switch on bitmask values here, because we can
+	 * only stop one scan type at a time.
+	 */
 	switch (scan_type) {
 	case IWL_MVM_SCAN_SCHED:
 		ret = iwl_mvm_scan_offload_stop(mvm, true);
 		break;
-	case IWL_MVM_SCAN_OS:
+	case IWL_MVM_SCAN_REGULAR:
 		ret = iwl_mvm_cancel_scan(mvm);
 		break;
-	case IWL_MVM_SCAN_NONE:
 	default:
 		WARN_ON_ONCE(1);
 		ret = -EINVAL;
@@ -2440,7 +2442,7 @@ static int iwl_mvm_mac_hw_scan(struct ieee80211_hw *hw,
 		goto out;
 	}
 
-	if (mvm->scan_status != IWL_MVM_SCAN_NONE) {
+	if (mvm->scan_status & IWL_MVM_SCAN_REGULAR) {
 		ret = -EBUSY;
 		goto out;
 	}
@@ -2476,7 +2478,7 @@ static void iwl_mvm_mac_cancel_hw_scan(struct ieee80211_hw *hw,
 	/* FIXME: for now, we ignore this race for UMAC scans, since
 	 * they don't set the scan_status.
 	 */
-	if ((mvm->scan_status == IWL_MVM_SCAN_OS) ||
+	if ((mvm->scan_status & IWL_MVM_SCAN_REGULAR) ||
 	    (mvm->fw->ucode_capa.capa[0] & IWL_UCODE_TLV_CAPA_UMAC_SCAN))
 		iwl_mvm_cancel_scan(mvm);
 
@@ -2797,7 +2799,7 @@ static int iwl_mvm_mac_sched_scan_start(struct ieee80211_hw *hw,
 	int ret;
 
 	if (!(mvm->fw->ucode_capa.capa[0] & IWL_UCODE_TLV_CAPA_UMAC_SCAN)) {
-		ret = iwl_mvm_cancel_scan_wait_notif(mvm, IWL_MVM_SCAN_OS);
+		ret = iwl_mvm_cancel_scan_wait_notif(mvm, IWL_MVM_SCAN_REGULAR);
 		if (ret)
 			return ret;
 	}
@@ -2815,14 +2817,14 @@ static int iwl_mvm_mac_sched_scan_start(struct ieee80211_hw *hw,
 		goto out;
 	}
 
-	if (mvm->scan_status != IWL_MVM_SCAN_NONE) {
+	if (mvm->scan_status & IWL_MVM_SCAN_SCHED) {
 		ret = -EBUSY;
 		goto out;
 	}
 
 	ret = iwl_mvm_scan_offload_start(mvm, vif, req, ies);
 	if (ret)
-		mvm->scan_status = IWL_MVM_SCAN_NONE;
+		mvm->scan_status &= ~IWL_MVM_SCAN_SCHED;
 
 out:
 	mutex_unlock(&mvm->mutex);
@@ -2848,7 +2850,7 @@ static int iwl_mvm_mac_sched_scan_stop(struct ieee80211_hw *hw,
 	/* FIXME: for now, we ignore this race for UMAC scans, since
 	 * they don't set the scan_status.
 	 */
-	if (mvm->scan_status != IWL_MVM_SCAN_SCHED &&
+	if (!(mvm->scan_status & IWL_MVM_SCAN_SCHED) &&
 	    !(mvm->fw->ucode_capa.capa[0] & IWL_UCODE_TLV_CAPA_UMAC_SCAN)) {
 		mutex_unlock(&mvm->mutex);
 		return 0;

drivers/net/wireless/iwlwifi/mvm/mvm.h

@@ -6,7 +6,7 @@
  * GPL LICENSE SUMMARY
  *
  * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
- * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
+ * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -32,7 +32,7 @@
  * BSD LICENSE
  *
  * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
- * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
+ * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -446,9 +446,19 @@ iwl_mvm_vif_from_mac80211(struct ieee80211_vif *vif)
 extern const u8 tid_to_mac80211_ac[];
 
 enum iwl_scan_status {
-	IWL_MVM_SCAN_NONE,
-	IWL_MVM_SCAN_OS,
-	IWL_MVM_SCAN_SCHED,
+	IWL_MVM_SCAN_REGULAR		= BIT(0),
+	IWL_MVM_SCAN_SCHED		= BIT(1),
+
+	IWL_MVM_SCAN_STOPPING_REGULAR	= BIT(8),
+	IWL_MVM_SCAN_STOPPING_SCHED	= BIT(9),
+
+	IWL_MVM_SCAN_REGULAR_MASK	= IWL_MVM_SCAN_REGULAR |
+					  IWL_MVM_SCAN_STOPPING_REGULAR,
+	IWL_MVM_SCAN_SCHED_MASK		= IWL_MVM_SCAN_SCHED |
+					  IWL_MVM_SCAN_STOPPING_SCHED,
+
+	IWL_MVM_SCAN_STOPPING_MASK	= 0xff00,
+	IWL_MVM_SCAN_MASK		= 0x00ff,
 };
 
 /**
@@ -647,7 +657,7 @@ struct iwl_mvm {
 	u32 rts_threshold;
 
 	/* Scan status, cmd (pre-allocated) and auxiliary station */
-	enum iwl_scan_status scan_status;
+	unsigned int scan_status;
 	void *scan_cmd;
 	struct iwl_mcast_filter_cmd *mcast_filter_cmd;
 

drivers/net/wireless/iwlwifi/mvm/scan.c

@@ -6,7 +6,7 @@
  * GPL LICENSE SUMMARY
  *
  * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
- * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
+ * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -32,7 +32,7 @@
  * BSD LICENSE
  *
  * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
- * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
+ * Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -358,36 +358,58 @@ int iwl_mvm_rx_scan_offload_complete_notif(struct iwl_mvm *mvm,
 					   struct iwl_device_cmd *cmd)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
-	struct iwl_periodic_scan_complete *scan_notif;
-
-	scan_notif = (void *)pkt->data;
+	struct iwl_periodic_scan_complete *scan_notif = (void *)pkt->data;
+	bool aborted = (scan_notif->status == IWL_SCAN_OFFLOAD_ABORTED);
+	bool ebs_successful = (scan_notif->ebs_status == IWL_SCAN_EBS_SUCCESS);
 
 	/* scan status must be locked for proper checking */
 	lockdep_assert_held(&mvm->mutex);
 
-	IWL_DEBUG_SCAN(mvm,
-		       "%s completed, status %s, EBS status %s\n",
-		       mvm->scan_status == IWL_MVM_SCAN_SCHED ?
-				"Scheduled scan" : "Scan",
-		       scan_notif->status == IWL_SCAN_OFFLOAD_COMPLETED ?
-				"completed" : "aborted",
-		       scan_notif->ebs_status == IWL_SCAN_EBS_SUCCESS ?
-				"success" : "failed");
+	/* We first check if we were stopping a scan, in which case we
+	 * just clear the stopping flag.  Then we check if it was a
+	 * firmware initiated stop, in which case we need to inform
+	 * mac80211.
+	 * Note that we can have a stopping and a running scan
+	 * simultaneously, but we can't have two different types of
+	 * scans stopping or running at the same time (since LMAC
+	 * doesn't support it).
+	 */
+
+	if (mvm->scan_status & IWL_MVM_SCAN_STOPPING_SCHED) {
+		WARN_ON_ONCE(mvm->scan_status & IWL_MVM_SCAN_STOPPING_REGULAR);
+
+		IWL_DEBUG_SCAN(mvm, "Scheduled scan %s, EBS status %s\n",
+			       aborted ? "aborted" : "completed",
+			       ebs_successful ? "successful" : "failed");
 
+		mvm->scan_status &= ~IWL_MVM_SCAN_STOPPING_SCHED;
+	} else if (mvm->scan_status & IWL_MVM_SCAN_STOPPING_REGULAR) {
+		IWL_DEBUG_SCAN(mvm, "Regular scan %s, EBS status %s\n",
+			       aborted ? "aborted" : "completed",
+			       ebs_successful ? "successful" : "failed");
 
-	/* 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;
+		mvm->scan_status &= ~IWL_MVM_SCAN_STOPPING_REGULAR;
+	} else if (mvm->scan_status & IWL_MVM_SCAN_SCHED) {
+		WARN_ON_ONCE(mvm->scan_status & IWL_MVM_SCAN_REGULAR);
+
+		IWL_DEBUG_SCAN(mvm, "Scheduled scan %s, EBS status %s (FW)\n",
+			       aborted ? "aborted" : "completed",
+			       ebs_successful ? "successful" : "failed");
+
+		mvm->scan_status &= ~IWL_MVM_SCAN_SCHED;
 		ieee80211_sched_scan_stopped(mvm->hw);
-	} else if (mvm->scan_status == IWL_MVM_SCAN_OS) {
-		mvm->scan_status = IWL_MVM_SCAN_NONE;
+	} else if (mvm->scan_status & IWL_MVM_SCAN_REGULAR) {
+		IWL_DEBUG_SCAN(mvm, "Regular scan %s, EBS status %s (FW)\n",
+			       aborted ? "aborted" : "completed",
+			       ebs_successful ? "successful" : "failed");
+
+		mvm->scan_status &= ~IWL_MVM_SCAN_REGULAR;
 		ieee80211_scan_completed(mvm->hw,
 				scan_notif->status == IWL_SCAN_OFFLOAD_ABORTED);
 		iwl_mvm_unref(mvm, IWL_MVM_REF_SCAN);
 	}
 
-	if (scan_notif->ebs_status)
-		mvm->last_ebs_successful = false;
+	mvm->last_ebs_successful = ebs_successful;
 
 	return 0;
 }
@@ -544,7 +566,7 @@ int iwl_mvm_scan_offload_start(struct iwl_mvm *mvm,
 			return ret;
 		ret = iwl_mvm_sched_scan_umac(mvm, vif, req, ies);
 	} else {
-		mvm->scan_status = IWL_MVM_SCAN_SCHED;
+		mvm->scan_status |= IWL_MVM_SCAN_SCHED;
 		ret = iwl_mvm_config_sched_scan_profiles(mvm, req);
 		if (ret)
 			return ret;
@@ -565,7 +587,7 @@ static int iwl_mvm_send_scan_offload_abort(struct iwl_mvm *mvm)
 	/* Exit instantly with error when device is not ready
 	 * to receive scan abort command or it does not perform
 	 * scheduled scan currently */
-	if (mvm->scan_status == IWL_MVM_SCAN_NONE)
+	if (!mvm->scan_status)
 		return -EIO;
 
 	ret = iwl_mvm_send_cmd_status(mvm, &cmd, &status);
@@ -592,7 +614,7 @@ int iwl_mvm_scan_offload_stop(struct iwl_mvm *mvm, bool notify)
 	int ret;
 	struct iwl_notification_wait wait_scan_done;
 	static const u8 scan_done_notif[] = { SCAN_OFFLOAD_COMPLETE, };
-	bool sched = mvm->scan_status == IWL_MVM_SCAN_SCHED;
+	bool sched = !!(mvm->scan_status & IWL_MVM_SCAN_SCHED);
 
 	lockdep_assert_held(&mvm->mutex);
 
@@ -600,7 +622,11 @@ int iwl_mvm_scan_offload_stop(struct iwl_mvm *mvm, bool notify)
 		return iwl_umac_scan_stop(mvm, IWL_UMAC_SCAN_UID_SCHED_SCAN,
 					  notify);
 
-	if (mvm->scan_status == IWL_MVM_SCAN_NONE)
+	/* FIXME: For now we only check if no scan is set here, since
+	 * we only support LMAC in this flow and it doesn't support
+	 * multiple scans.
+	 */
+	if (!mvm->scan_status)
 		return 0;
 
 	if (iwl_mvm_is_radio_killed(mvm)) {
@@ -622,25 +648,28 @@ int iwl_mvm_scan_offload_stop(struct iwl_mvm *mvm, bool notify)
 	}
 
 	IWL_DEBUG_SCAN(mvm, "Successfully sent stop %sscan\n",
-		       sched ? "offloaded " : "");
+		       sched ? "scheduled " : "");
 
 	ret = iwl_wait_notification(&mvm->notif_wait, &wait_scan_done, 1 * HZ);
 out:
-	/*
-	 * 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. Since the rx handler won't do anything now,
-	 * we have to release the scan reference here.
+	/* Clear the scan status so the next scan requests will
+	 * succeed and mark the scan as stopping, so that the Rx
+	 * handler doesn't do anything, as the scan was stopped from
+	 * above. Since the rx handler won't do anything now, we have
+	 * to release the scan reference here.
 	 */
-	if (mvm->scan_status == IWL_MVM_SCAN_OS)
+	if (mvm->scan_status == IWL_MVM_SCAN_REGULAR)
 		iwl_mvm_unref(mvm, IWL_MVM_REF_SCAN);
 
-	mvm->scan_status = IWL_MVM_SCAN_NONE;
-
-	if (notify) {
-		if (sched)
+	if (sched) {
+		mvm->scan_status &= ~IWL_MVM_SCAN_SCHED;
+		mvm->scan_status |= IWL_MVM_SCAN_STOPPING_SCHED;
+		if (notify)
 			ieee80211_sched_scan_stopped(mvm->hw);
-		else
+	} else {
+		mvm->scan_status &= ~IWL_MVM_SCAN_REGULAR;
+		mvm->scan_status |= IWL_MVM_SCAN_STOPPING_REGULAR;
+		if (notify)
 			ieee80211_scan_completed(mvm->hw, true);
 	}
 
@@ -829,7 +858,7 @@ int iwl_mvm_unified_scan_lmac(struct iwl_mvm *mvm,
 	    req->req.n_channels > mvm->fw->ucode_capa.n_scan_channels)
 		return -ENOBUFS;
 
-	mvm->scan_status = IWL_MVM_SCAN_OS;
+	mvm->scan_status |= IWL_MVM_SCAN_REGULAR;
 
 	iwl_mvm_scan_calc_params(mvm, vif, req->req.n_ssids, req->req.flags,
 				 &params);
@@ -906,7 +935,7 @@ int iwl_mvm_unified_scan_lmac(struct iwl_mvm *mvm,
 		 * should try to send the command again with different params.
 		 */
 		IWL_ERR(mvm, "Scan failed! ret %d\n", ret);
-		mvm->scan_status = IWL_MVM_SCAN_NONE;
+		mvm->scan_status &= ~IWL_MVM_SCAN_REGULAR;
 		ret = -EIO;
 	}
 	return ret;
@@ -1026,7 +1055,7 @@ int iwl_mvm_unified_sched_scan_lmac(struct iwl_mvm *mvm,
 		 * should try to send the command again with different params.
 		 */
 		IWL_ERR(mvm, "Sched scan failed! ret %d\n", ret);
-		mvm->scan_status = IWL_MVM_SCAN_NONE;
+		mvm->scan_status &= ~IWL_MVM_SCAN_SCHED;
 		ret = -EIO;
 	}
 	return ret;
@@ -1039,13 +1068,13 @@ int iwl_mvm_cancel_scan(struct iwl_mvm *mvm)
 		return iwl_umac_scan_stop(mvm, IWL_UMAC_SCAN_UID_REG_SCAN,
 					  true);
 
-	if (mvm->scan_status == IWL_MVM_SCAN_NONE)
+	if (!(mvm->scan_status & IWL_MVM_SCAN_REGULAR))
 		return 0;
 
 	if (iwl_mvm_is_radio_killed(mvm)) {
 		ieee80211_scan_completed(mvm->hw, true);
 		iwl_mvm_unref(mvm, IWL_MVM_REF_SCAN);
-		mvm->scan_status = IWL_MVM_SCAN_NONE;
+		mvm->scan_status &= ~IWL_MVM_SCAN_REGULAR;
 		return 0;
 	}
 
@@ -1682,21 +1711,14 @@ void iwl_mvm_report_scan_aborted(struct iwl_mvm *mvm)
 				mvm->scan_uid[i] = 0;
 		}
 	} else {
-		switch (mvm->scan_status) {
-		case IWL_MVM_SCAN_NONE:
-			break;
-		case IWL_MVM_SCAN_OS:
+		if (mvm->scan_status & IWL_MVM_SCAN_REGULAR)
 			ieee80211_scan_completed(mvm->hw, true);
-			break;
-		case IWL_MVM_SCAN_SCHED:
-			/*
-			 * Sched scan will be restarted by mac80211 in
-			 * restart_hw, so do not report if FW is about to be
-			 * restarted.
-			 */
-			if (!mvm->restart_fw)
-				ieee80211_sched_scan_stopped(mvm->hw);
-			break;
-		}
+
+		/* Sched scan will be restarted by mac80211 in
+		 * restart_hw, so do not report if FW is about to be
+		 * restarted.
+		 */
+		if ((mvm->scan_status & IWL_MVM_SCAN_SCHED) && !mvm->restart_fw)
+			ieee80211_sched_scan_stopped(mvm->hw);
 	}
 }