drivers/net/wireless/iwlwifi/iwl-scan.c - arm/linux-arm64-legacy - Git at Google

 /******************************************************************************
  *
  * GPL LICENSE SUMMARY
  *
  * Copyright(c) 2008 - 2010 Intel Corporation. All rights reserved.
  *
  * 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
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
  * USA
  *
  * The full GNU General Public License is included in this distribution
  * in the file called LICENSE.GPL.
  *
  * Contact Information:
  *  Intel Linux Wireless <ilw@linux.intel.com>
  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  *****************************************************************************/
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/etherdevice.h>
 #include <net/mac80211.h>

 #include "iwl-eeprom.h"
 #include "iwl-dev.h"
 #include "iwl-core.h"
 #include "iwl-sta.h"
 #include "iwl-io.h"
 #include "iwl-helpers.h"

 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  * sending probe req.  This should be set long enough to hear probe responses
  * from more than one AP.  */
 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
 #define IWL_ACTIVE_DWELL_TIME_52    (20)

 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)

 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  * Must be set longer than active dwell time.
  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
 #define IWL_PASSIVE_DWELL_TIME_52   (10)
 #define IWL_PASSIVE_DWELL_BASE      (100)
 #define IWL_CHANNEL_TUNE_TIME       5


 /**
  * iwl_scan_cancel - Cancel any currently executing HW scan
  *
  * NOTE: priv->mutex is not required before calling this function
  */
 int iwl_scan_cancel(struct iwl_priv *priv)
 {
 	if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
 		clear_bit(STATUS_SCANNING, &priv->status);
 		return 0;
 	}

 	if (test_bit(STATUS_SCANNING, &priv->status)) {
 		if (!test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 			IWL_DEBUG_SCAN(priv, "Queuing scan abort.\n");
 			queue_work(priv->workqueue, &priv->abort_scan);

 		} else
 			IWL_DEBUG_SCAN(priv, "Scan abort already in progress.\n");

 		return test_bit(STATUS_SCANNING, &priv->status);
 	}

 	return 0;
 }
 EXPORT_SYMBOL(iwl_scan_cancel);
 /**
  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
  * @ms: amount of time to wait (in milliseconds) for scan to abort
  *
  * NOTE: priv->mutex must be held before calling this function
  */
 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 {
 	unsigned long now = jiffies;
 	int ret;

 	ret = iwl_scan_cancel(priv);
 	if (ret && ms) {
 		mutex_unlock(&priv->mutex);
 		while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
 				test_bit(STATUS_SCANNING, &priv->status))
 			msleep(1);
 		mutex_lock(&priv->mutex);

 		return test_bit(STATUS_SCANNING, &priv->status);
 	}

 	return ret;
 }
 EXPORT_SYMBOL(iwl_scan_cancel_timeout);

 static int iwl_send_scan_abort(struct iwl_priv *priv)
 {
 	int ret = 0;
 	struct iwl_rx_packet *pkt;
 	struct iwl_host_cmd cmd = {
 		.id = REPLY_SCAN_ABORT_CMD,
 		.flags = CMD_WANT_SKB,
 	};

 	/* If there isn't a scan actively going on in the hardware
 	 * then we are in between scan bands and not actually
 	 * actively scanning, so don't send the abort command */
 	if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
 		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 		return 0;
 	}

 	ret = iwl_send_cmd_sync(priv, &cmd);
 	if (ret) {
 		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 		return ret;
 	}

 	pkt = (struct iwl_rx_packet *)cmd.reply_page;
 	if (pkt->u.status != CAN_ABORT_STATUS) {
 		/* The scan abort will return 1 for success or
 		 * 2 for "failure".  A failure condition can be
 		 * due to simply not being in an active scan which
 		 * can occur if we send the scan abort before we
 		 * the microcode has notified us that a scan is
 		 * completed. */
 		IWL_DEBUG_INFO(priv, "SCAN_ABORT returned %d.\n", pkt->u.status);
 		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 		clear_bit(STATUS_SCAN_HW, &priv->status);
 	}

 	iwl_free_pages(priv, cmd.reply_page);

 	return ret;
 }

 /* Service response to REPLY_SCAN_CMD (0x80) */
 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 			      struct iwl_rx_mem_buffer *rxb)
 {
 #ifdef CONFIG_IWLWIFI_DEBUG
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
 	struct iwl_scanreq_notification *notif =
 	    (struct iwl_scanreq_notification *)pkt->u.raw;

 	IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
 #endif
 }

 /* Service SCAN_START_NOTIFICATION (0x82) */
 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 				    struct iwl_rx_mem_buffer *rxb)
 {
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
 	struct iwl_scanstart_notification *notif =
 	    (struct iwl_scanstart_notification *)pkt->u.raw;
 	priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 	IWL_DEBUG_SCAN(priv, "Scan start: "
 		       "%d [802.11%s] "
 		       "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 		       notif->channel,
 		       notif->band ? "bg" : "a",
 		       le32_to_cpu(notif->tsf_high),
 		       le32_to_cpu(notif->tsf_low),
 		       notif->status, notif->beacon_timer);
 }

 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 				      struct iwl_rx_mem_buffer *rxb)
 {
 #ifdef CONFIG_IWLWIFI_DEBUG
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
 	struct iwl_scanresults_notification *notif =
 	    (struct iwl_scanresults_notification *)pkt->u.raw;

 	IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 		       "%d [802.11%s] "
 		       "(TSF: 0x%08X:%08X) - %d "
 		       "elapsed=%lu usec\n",
 		       notif->channel,
 		       notif->band ? "bg" : "a",
 		       le32_to_cpu(notif->tsf_high),
 		       le32_to_cpu(notif->tsf_low),
 		       le32_to_cpu(notif->statistics[0]),
 		       le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 #endif
 }

 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 				       struct iwl_rx_mem_buffer *rxb)
 {
 #ifdef CONFIG_IWLWIFI_DEBUG
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
 	struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;

 	IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 		       scan_notif->scanned_channels,
 		       scan_notif->tsf_low,
 		       scan_notif->tsf_high, scan_notif->status);
 #endif

 	/* The HW is no longer scanning */
 	clear_bit(STATUS_SCAN_HW, &priv->status);

 	IWL_DEBUG_INFO(priv, "Scan on %sGHz took %dms\n",
 		       (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
 		       jiffies_to_msecs(elapsed_jiffies
 					(priv->scan_start, jiffies)));

 	/*
 	 * If a request to abort was given, or the scan did not succeed
 	 * then we reset the scan state machine and terminate,
 	 * re-queuing another scan if one has been requested
 	 */
 	if (test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status))
 		IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");

 	IWL_DEBUG_INFO(priv, "Setting scan to off\n");

 	clear_bit(STATUS_SCANNING, &priv->status);

 	queue_work(priv->workqueue, &priv->scan_completed);
 }

 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 {
 	/* scan handlers */
 	priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 	priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 	priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 					iwl_rx_scan_results_notif;
 	priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 					iwl_rx_scan_complete_notif;
 }
 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);

 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 				     enum ieee80211_band band,
 				     u8 n_probes)
 {
 	if (band == IEEE80211_BAND_5GHZ)
 		return IWL_ACTIVE_DWELL_TIME_52 +
 			IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 	else
 		return IWL_ACTIVE_DWELL_TIME_24 +
 			IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 }
 EXPORT_SYMBOL(iwl_get_active_dwell_time);

 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 			       enum ieee80211_band band,
 			       struct ieee80211_vif *vif)
 {
 	u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;

 	if (iwl_is_associated(priv)) {
 		/* If we're associated, we clamp the maximum passive
 		 * dwell time to be 98% of the beacon interval (minus
 		 * 2 * channel tune time) */
 		passive = vif ? vif->bss_conf.beacon_int : 0;
 		if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
 			passive = IWL_PASSIVE_DWELL_BASE;
 		passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 	}

 	return passive;
 }
 EXPORT_SYMBOL(iwl_get_passive_dwell_time);

 void iwl_init_scan_params(struct iwl_priv *priv)
 {
 	u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 	if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 		priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 	if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 		priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 }
 EXPORT_SYMBOL(iwl_init_scan_params);

 static int iwl_scan_initiate(struct iwl_priv *priv, struct ieee80211_vif *vif)
 {
 	WARN_ON(!mutex_is_locked(&priv->mutex));

 	IWL_DEBUG_INFO(priv, "Starting scan...\n");
 	set_bit(STATUS_SCANNING, &priv->status);
 	priv->is_internal_short_scan = false;
 	priv->scan_start = jiffies;

 	if (WARN_ON(!priv->cfg->ops->utils->request_scan))
 		return -EOPNOTSUPP;

 	priv->cfg->ops->utils->request_scan(priv, vif);

 	return 0;
 }

 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
 		    struct ieee80211_vif *vif,
 		    struct cfg80211_scan_request *req)
 {
 	struct iwl_priv *priv = hw->priv;
 	int ret;

 	IWL_DEBUG_MAC80211(priv, "enter\n");

 	if (req->n_channels == 0)
 		return -EINVAL;

 	mutex_lock(&priv->mutex);

 	if (!iwl_is_ready_rf(priv)) {
 		ret = -EIO;
 		IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
 		goto out_unlock;
 	}

 	if (test_bit(STATUS_SCANNING, &priv->status) &&
 	    !priv->is_internal_short_scan) {
 		IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 		ret = -EAGAIN;
 		goto out_unlock;
 	}

 	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 		IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
 		ret = -EAGAIN;
 		goto out_unlock;
 	}

 	/* mac80211 will only ask for one band at a time */
 	priv->scan_band = req->channels[0]->band;
 	priv->scan_request = req;
 	priv->scan_vif = vif;

 	/*
 	 * If an internal scan is in progress, just set
 	 * up the scan_request as per above.
 	 */
 	if (priv->is_internal_short_scan)
 		ret = 0;
 	else
 		ret = iwl_scan_initiate(priv, vif);

 	IWL_DEBUG_MAC80211(priv, "leave\n");

 out_unlock:
 	mutex_unlock(&priv->mutex);

 	return ret;
 }
 EXPORT_SYMBOL(iwl_mac_hw_scan);

 /*
  * internal short scan, this function should only been called while associated.
  * It will reset and tune the radio to prevent possible RF related problem
  */
 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
 {
 	queue_work(priv->workqueue, &priv->start_internal_scan);
 }

 void iwl_bg_start_internal_scan(struct work_struct *work)
 {
 	struct iwl_priv *priv =
 		container_of(work, struct iwl_priv, start_internal_scan);

 	mutex_lock(&priv->mutex);

 	if (priv->is_internal_short_scan == true) {
 		IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
 		goto unlock;
 	}

 	if (!iwl_is_ready_rf(priv)) {
 		IWL_DEBUG_SCAN(priv, "not ready or exit pending\n");
 		goto unlock;
 	}

 	if (test_bit(STATUS_SCANNING, &priv->status)) {
 		IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 		goto unlock;
 	}

 	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 		IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
 		goto unlock;
 	}

 	priv->scan_band = priv->band;

 	IWL_DEBUG_SCAN(priv, "Start internal short scan...\n");
 	set_bit(STATUS_SCANNING, &priv->status);
 	priv->is_internal_short_scan = true;

 	if (WARN_ON(!priv->cfg->ops->utils->request_scan))
 		goto unlock;

 	priv->cfg->ops->utils->request_scan(priv, NULL);
  unlock:
 	mutex_unlock(&priv->mutex);
 }
 EXPORT_SYMBOL(iwl_bg_start_internal_scan);

 void iwl_bg_scan_check(struct work_struct *data)
 {
 	struct iwl_priv *priv =
 	    container_of(data, struct iwl_priv, scan_check.work);

 	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 		return;

 	mutex_lock(&priv->mutex);
 	if (test_bit(STATUS_SCANNING, &priv->status) ||
 	    test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 		IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
 			"adapter (%dms)\n",
 			jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));

 		if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
 			iwl_send_scan_abort(priv);
 	}
 	mutex_unlock(&priv->mutex);
 }
 EXPORT_SYMBOL(iwl_bg_scan_check);

 /**
  * iwl_fill_probe_req - fill in all required fields and IE for probe request
  */

 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
 		       const u8 *ta, const u8 *ies, int ie_len, int left)
 {
 	int len = 0;
 	u8 *pos = NULL;

 	/* Make sure there is enough space for the probe request,
 	 * two mandatory IEs and the data */
 	left -= 24;
 	if (left < 0)
 		return 0;

 	frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 	memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 	memcpy(frame->sa, ta, ETH_ALEN);
 	memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 	frame->seq_ctrl = 0;

 	len += 24;

 	/* ...next IE... */
 	pos = &frame->u.probe_req.variable[0];

 	/* fill in our indirect SSID IE */
 	left -= 2;
 	if (left < 0)
 		return 0;
 	*pos++ = WLAN_EID_SSID;
 	*pos++ = 0;

 	len += 2;

 	if (WARN_ON(left < ie_len))
 		return len;

 	if (ies && ie_len) {
 		memcpy(pos, ies, ie_len);
 		len += ie_len;
 	}

 	return (u16)len;
 }
 EXPORT_SYMBOL(iwl_fill_probe_req);

 void iwl_bg_abort_scan(struct work_struct *work)
 {
 	struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);

 	if (!test_bit(STATUS_READY, &priv->status) ||
 	    !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
 		return;

 	mutex_lock(&priv->mutex);

 	cancel_delayed_work_sync(&priv->scan_check);
 	set_bit(STATUS_SCAN_ABORTING, &priv->status);
 	iwl_send_scan_abort(priv);

 	mutex_unlock(&priv->mutex);
 }
 EXPORT_SYMBOL(iwl_bg_abort_scan);

 void iwl_bg_scan_completed(struct work_struct *work)
 {
 	struct iwl_priv *priv =
 	    container_of(work, struct iwl_priv, scan_completed);
 	bool internal = false;

 	IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");

 	cancel_delayed_work(&priv->scan_check);

 	mutex_lock(&priv->mutex);
 	if (priv->is_internal_short_scan) {
 		priv->is_internal_short_scan = false;
 		IWL_DEBUG_SCAN(priv, "internal short scan completed\n");
 		internal = true;
 	} else {
 		priv->scan_request = NULL;
 		priv->scan_vif = NULL;
 	}

 	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 		goto out;

 	if (internal && priv->scan_request)
 		iwl_scan_initiate(priv, priv->scan_vif);

 	/* Since setting the TXPOWER may have been deferred while
 	 * performing the scan, fire one off */
 	iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);

 	/*
 	 * Since setting the RXON may have been deferred while
 	 * performing the scan, fire one off if needed
 	 */
 	if (memcmp(&priv->active_rxon,
 		   &priv->staging_rxon, sizeof(priv->staging_rxon)))
 		iwlcore_commit_rxon(priv);

  out:
 	mutex_unlock(&priv->mutex);

 	/*
 	 * Do not hold mutex here since this will cause mac80211 to call
 	 * into driver again into functions that will attempt to take
 	 * mutex.
 	 */
 	if (!internal)
 		ieee80211_scan_completed(priv->hw, false);
 }
 EXPORT_SYMBOL(iwl_bg_scan_completed);

 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 {
 	INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 	INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 	INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
 	INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 }
 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
	/******************************************************************************
	*
	* GPL LICENSE SUMMARY
	*
	* Copyright(c) 2008 - 2010 Intel Corporation. All rights reserved.
	*
	* 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
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
	* USA
	*
	* The full GNU General Public License is included in this distribution
	* in the file called LICENSE.GPL.
	*
	* Contact Information:
	* Intel Linux Wireless <ilw@linux.intel.com>
	* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
	*****************************************************************************/
	#include <linux/slab.h>
	#include <linux/types.h>
	#include <linux/etherdevice.h>
	#include <net/mac80211.h>

	#include "iwl-eeprom.h"
	#include "iwl-dev.h"
	#include "iwl-core.h"
	#include "iwl-sta.h"
	#include "iwl-io.h"
	#include "iwl-helpers.h"

	/* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
	* sending probe req. This should be set long enough to hear probe responses
	* from more than one AP. */
	#define IWL_ACTIVE_DWELL_TIME_24 (30) /* all times in msec */
	#define IWL_ACTIVE_DWELL_TIME_52 (20)

	#define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
	#define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)

	/* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
	* Must be set longer than active dwell time.
	* For the most reliable scan, set > AP beacon interval (typically 100msec). */
	#define IWL_PASSIVE_DWELL_TIME_24 (20) /* all times in msec */
	#define IWL_PASSIVE_DWELL_TIME_52 (10)
	#define IWL_PASSIVE_DWELL_BASE (100)
	#define IWL_CHANNEL_TUNE_TIME 5



	/**
	* iwl_scan_cancel - Cancel any currently executing HW scan
	*
	* NOTE: priv->mutex is not required before calling this function
	*/
	int iwl_scan_cancel(struct iwl_priv *priv)
	{
	if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
	clear_bit(STATUS_SCANNING, &priv->status);
	return 0;
	}

	if (test_bit(STATUS_SCANNING, &priv->status)) {
	if (!test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
	IWL_DEBUG_SCAN(priv, "Queuing scan abort.\n");
	queue_work(priv->workqueue, &priv->abort_scan);

	} else
	IWL_DEBUG_SCAN(priv, "Scan abort already in progress.\n");

	return test_bit(STATUS_SCANNING, &priv->status);
	}

	return 0;
	}
	EXPORT_SYMBOL(iwl_scan_cancel);
	/**
	* iwl_scan_cancel_timeout - Cancel any currently executing HW scan
	* @ms: amount of time to wait (in milliseconds) for scan to abort
	*
	* NOTE: priv->mutex must be held before calling this function
	*/
	int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
	{
	unsigned long now = jiffies;
	int ret;

	ret = iwl_scan_cancel(priv);
	if (ret && ms) {
	mutex_unlock(&priv->mutex);
	while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
	test_bit(STATUS_SCANNING, &priv->status))
	msleep(1);
	mutex_lock(&priv->mutex);

	return test_bit(STATUS_SCANNING, &priv->status);
	}

	return ret;
	}
	EXPORT_SYMBOL(iwl_scan_cancel_timeout);

	static int iwl_send_scan_abort(struct iwl_priv *priv)
	{
	int ret = 0;
	struct iwl_rx_packet *pkt;
	struct iwl_host_cmd cmd = {
	.id = REPLY_SCAN_ABORT_CMD,
	.flags = CMD_WANT_SKB,
	};

	/* If there isn't a scan actively going on in the hardware
	* then we are in between scan bands and not actually
	* actively scanning, so don't send the abort command */
	if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
	clear_bit(STATUS_SCAN_ABORTING, &priv->status);
	return 0;
	}

	ret = iwl_send_cmd_sync(priv, &cmd);
	if (ret) {
	clear_bit(STATUS_SCAN_ABORTING, &priv->status);
	return ret;
	}

	pkt = (struct iwl_rx_packet *)cmd.reply_page;
	if (pkt->u.status != CAN_ABORT_STATUS) {
	/* The scan abort will return 1 for success or
	* 2 for "failure". A failure condition can be
	* due to simply not being in an active scan which
	* can occur if we send the scan abort before we
	* the microcode has notified us that a scan is
	* completed. */
	IWL_DEBUG_INFO(priv, "SCAN_ABORT returned %d.\n", pkt->u.status);
	clear_bit(STATUS_SCAN_ABORTING, &priv->status);
	clear_bit(STATUS_SCAN_HW, &priv->status);
	}

	iwl_free_pages(priv, cmd.reply_page);

	return ret;
	}

	/* Service response to REPLY_SCAN_CMD (0x80) */
	static void iwl_rx_reply_scan(struct iwl_priv *priv,
	struct iwl_rx_mem_buffer *rxb)
	{
	#ifdef CONFIG_IWLWIFI_DEBUG
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl_scanreq_notification *notif =
	(struct iwl_scanreq_notification *)pkt->u.raw;

	IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
	#endif
	}

	/* Service SCAN_START_NOTIFICATION (0x82) */
	static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
	struct iwl_rx_mem_buffer *rxb)
	{
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl_scanstart_notification *notif =
	(struct iwl_scanstart_notification *)pkt->u.raw;
	priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
	IWL_DEBUG_SCAN(priv, "Scan start: "
	"%d [802.11%s] "
	"(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
	notif->channel,
	notif->band ? "bg" : "a",
	le32_to_cpu(notif->tsf_high),
	le32_to_cpu(notif->tsf_low),
	notif->status, notif->beacon_timer);
	}

	/* Service SCAN_RESULTS_NOTIFICATION (0x83) */
	static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
	struct iwl_rx_mem_buffer *rxb)
	{
	#ifdef CONFIG_IWLWIFI_DEBUG
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl_scanresults_notification *notif =
	(struct iwl_scanresults_notification *)pkt->u.raw;

	IWL_DEBUG_SCAN(priv, "Scan ch.res: "
	"%d [802.11%s] "
	"(TSF: 0x%08X:%08X) - %d "
	"elapsed=%lu usec\n",
	notif->channel,
	notif->band ? "bg" : "a",
	le32_to_cpu(notif->tsf_high),
	le32_to_cpu(notif->tsf_low),
	le32_to_cpu(notif->statistics[0]),
	le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
	#endif
	}

	/* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
	static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
	struct iwl_rx_mem_buffer *rxb)
	{
	#ifdef CONFIG_IWLWIFI_DEBUG
	struct iwl_rx_packet *pkt = rxb_addr(rxb);
	struct iwl_scancomplete_notification scan_notif = (void )pkt->u.raw;

	IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
	scan_notif->scanned_channels,
	scan_notif->tsf_low,
	scan_notif->tsf_high, scan_notif->status);
	#endif

	/* The HW is no longer scanning */
	clear_bit(STATUS_SCAN_HW, &priv->status);

	IWL_DEBUG_INFO(priv, "Scan on %sGHz took %dms\n",
	(priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
	jiffies_to_msecs(elapsed_jiffies
	(priv->scan_start, jiffies)));

	/*
	* If a request to abort was given, or the scan did not succeed
	* then we reset the scan state machine and terminate,
	* re-queuing another scan if one has been requested
	*/
	if (test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status))
	IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");

	IWL_DEBUG_INFO(priv, "Setting scan to off\n");

	clear_bit(STATUS_SCANNING, &priv->status);

	queue_work(priv->workqueue, &priv->scan_completed);
	}

	void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
	{
	/* scan handlers */
	priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
	priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
	priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
	iwl_rx_scan_results_notif;
	priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
	iwl_rx_scan_complete_notif;
	}
	EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);

	inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
	enum ieee80211_band band,
	u8 n_probes)
	{
	if (band == IEEE80211_BAND_5GHZ)
	return IWL_ACTIVE_DWELL_TIME_52 +
	IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
	else
	return IWL_ACTIVE_DWELL_TIME_24 +
	IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
	}
	EXPORT_SYMBOL(iwl_get_active_dwell_time);

	u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
	enum ieee80211_band band,
	struct ieee80211_vif *vif)
	{
	u16 passive = (band == IEEE80211_BAND_2GHZ) ?
	IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
	IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;

	if (iwl_is_associated(priv)) {
	/* If we're associated, we clamp the maximum passive
	* dwell time to be 98% of the beacon interval (minus
	* 2 * channel tune time) */
	passive = vif ? vif->bss_conf.beacon_int : 0;
	if ((passive > IWL_PASSIVE_DWELL_BASE) \|\| !passive)
	passive = IWL_PASSIVE_DWELL_BASE;
	passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
	}

	return passive;
	}
	EXPORT_SYMBOL(iwl_get_passive_dwell_time);

	void iwl_init_scan_params(struct iwl_priv *priv)
	{
	u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
	if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
	priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
	if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
	priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
	}
	EXPORT_SYMBOL(iwl_init_scan_params);

	static int iwl_scan_initiate(struct iwl_priv priv, struct ieee80211_vif vif)
	{
	WARN_ON(!mutex_is_locked(&priv->mutex));

	IWL_DEBUG_INFO(priv, "Starting scan...\n");
	set_bit(STATUS_SCANNING, &priv->status);
	priv->is_internal_short_scan = false;
	priv->scan_start = jiffies;

	if (WARN_ON(!priv->cfg->ops->utils->request_scan))
	return -EOPNOTSUPP;

	priv->cfg->ops->utils->request_scan(priv, vif);

	return 0;
	}

	int iwl_mac_hw_scan(struct ieee80211_hw *hw,
	struct ieee80211_vif *vif,
	struct cfg80211_scan_request *req)
	{
	struct iwl_priv *priv = hw->priv;
	int ret;

	IWL_DEBUG_MAC80211(priv, "enter\n");

	if (req->n_channels == 0)
	return -EINVAL;

	mutex_lock(&priv->mutex);

	if (!iwl_is_ready_rf(priv)) {
	ret = -EIO;
	IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
	goto out_unlock;
	}

	if (test_bit(STATUS_SCANNING, &priv->status) &&
	!priv->is_internal_short_scan) {
	IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
	ret = -EAGAIN;
	goto out_unlock;
	}

	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
	IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
	ret = -EAGAIN;
	goto out_unlock;
	}

	/* mac80211 will only ask for one band at a time */
	priv->scan_band = req->channels[0]->band;
	priv->scan_request = req;
	priv->scan_vif = vif;

	/*
	* If an internal scan is in progress, just set
	* up the scan_request as per above.
	*/
	if (priv->is_internal_short_scan)
	ret = 0;
	else
	ret = iwl_scan_initiate(priv, vif);

	IWL_DEBUG_MAC80211(priv, "leave\n");

	out_unlock:
	mutex_unlock(&priv->mutex);

	return ret;
	}
	EXPORT_SYMBOL(iwl_mac_hw_scan);

	/*
	* internal short scan, this function should only been called while associated.
	* It will reset and tune the radio to prevent possible RF related problem
	*/
	void iwl_internal_short_hw_scan(struct iwl_priv *priv)
	{
	queue_work(priv->workqueue, &priv->start_internal_scan);
	}

	void iwl_bg_start_internal_scan(struct work_struct *work)
	{
	struct iwl_priv *priv =
	container_of(work, struct iwl_priv, start_internal_scan);

	mutex_lock(&priv->mutex);

	if (priv->is_internal_short_scan == true) {
	IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
	goto unlock;
	}

	if (!iwl_is_ready_rf(priv)) {
	IWL_DEBUG_SCAN(priv, "not ready or exit pending\n");
	goto unlock;
	}

	if (test_bit(STATUS_SCANNING, &priv->status)) {
	IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
	goto unlock;
	}

	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
	IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
	goto unlock;
	}

	priv->scan_band = priv->band;

	IWL_DEBUG_SCAN(priv, "Start internal short scan...\n");
	set_bit(STATUS_SCANNING, &priv->status);
	priv->is_internal_short_scan = true;

	if (WARN_ON(!priv->cfg->ops->utils->request_scan))
	goto unlock;

	priv->cfg->ops->utils->request_scan(priv, NULL);
	unlock:
	mutex_unlock(&priv->mutex);
	}
	EXPORT_SYMBOL(iwl_bg_start_internal_scan);

	void iwl_bg_scan_check(struct work_struct *data)
	{
	struct iwl_priv *priv =
	container_of(data, struct iwl_priv, scan_check.work);

	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
	return;

	mutex_lock(&priv->mutex);
	if (test_bit(STATUS_SCANNING, &priv->status) \|\|
	test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
	IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
	"adapter (%dms)\n",
	jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));

	if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
	iwl_send_scan_abort(priv);
	}
	mutex_unlock(&priv->mutex);
	}
	EXPORT_SYMBOL(iwl_bg_scan_check);

	/**
	* iwl_fill_probe_req - fill in all required fields and IE for probe request
	*/

	u16 iwl_fill_probe_req(struct iwl_priv priv, struct ieee80211_mgmt frame,
	const u8 ta, const u8 ies, int ie_len, int left)
	{
	int len = 0;
	u8 *pos = NULL;

	/* Make sure there is enough space for the probe request,
	* two mandatory IEs and the data */
	left -= 24;
	if (left < 0)
	return 0;

	frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
	memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
	memcpy(frame->sa, ta, ETH_ALEN);
	memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
	frame->seq_ctrl = 0;

	len += 24;

	/* ...next IE... */
	pos = &frame->u.probe_req.variable[0];

	/* fill in our indirect SSID IE */
	left -= 2;
	if (left < 0)
	return 0;
	*pos++ = WLAN_EID_SSID;
	*pos++ = 0;

	len += 2;

	if (WARN_ON(left < ie_len))
	return len;

	if (ies && ie_len) {
	memcpy(pos, ies, ie_len);
	len += ie_len;
	}

	return (u16)len;
	}
	EXPORT_SYMBOL(iwl_fill_probe_req);

	void iwl_bg_abort_scan(struct work_struct *work)
	{
	struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);

	if (!test_bit(STATUS_READY, &priv->status) \|\|
	!test_bit(STATUS_GEO_CONFIGURED, &priv->status))
	return;

	mutex_lock(&priv->mutex);

	cancel_delayed_work_sync(&priv->scan_check);
	set_bit(STATUS_SCAN_ABORTING, &priv->status);
	iwl_send_scan_abort(priv);

	mutex_unlock(&priv->mutex);
	}
	EXPORT_SYMBOL(iwl_bg_abort_scan);

	void iwl_bg_scan_completed(struct work_struct *work)
	{
	struct iwl_priv *priv =
	container_of(work, struct iwl_priv, scan_completed);
	bool internal = false;

	IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");

	cancel_delayed_work(&priv->scan_check);

	mutex_lock(&priv->mutex);
	if (priv->is_internal_short_scan) {
	priv->is_internal_short_scan = false;
	IWL_DEBUG_SCAN(priv, "internal short scan completed\n");
	internal = true;
	} else {
	priv->scan_request = NULL;
	priv->scan_vif = NULL;
	}

	if (test_bit(STATUS_EXIT_PENDING, &priv->status))
	goto out;

	if (internal && priv->scan_request)
	iwl_scan_initiate(priv, priv->scan_vif);

	/* Since setting the TXPOWER may have been deferred while
	* performing the scan, fire one off */
	iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);

	/*
	* Since setting the RXON may have been deferred while
	* performing the scan, fire one off if needed
	*/
	if (memcmp(&priv->active_rxon,
	&priv->staging_rxon, sizeof(priv->staging_rxon)))
	iwlcore_commit_rxon(priv);

	out:
	mutex_unlock(&priv->mutex);

	/*
	* Do not hold mutex here since this will cause mac80211 to call
	* into driver again into functions that will attempt to take
	* mutex.
	*/
	if (!internal)
	ieee80211_scan_completed(priv->hw, false);
	}
	EXPORT_SYMBOL(iwl_bg_scan_completed);

	void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
	{
	INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
	INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
	INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
	INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
	}
	EXPORT_SYMBOL(iwl_setup_scan_deferred_work);