Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1079 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/dvm/scan.c b/drivers/net/wireless/intel/iwlwifi/dvm/scan.c
new file mode 100644
index 000000000..17e6a3238
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/dvm/scan.c
@@ -0,0 +1,1079 @@
+/******************************************************************************
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2008 - 2014 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 COPYING.
+ *
+ * Contact Information:
+ *  Intel Linux Wireless <linuxwifi@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 "dev.h"
+#include "agn.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
+#define MAX_SCAN_CHANNEL	    50
+
+/* For reset radio, need minimal dwell time only */
+#define IWL_RADIO_RESET_DWELL_TIME	5
+
+static int iwl_send_scan_abort(struct iwl_priv *priv)
+{
+	int ret;
+	struct iwl_host_cmd cmd = {
+		.id = REPLY_SCAN_ABORT_CMD,
+		.flags = CMD_WANT_SKB,
+	};
+	__le32 *status;
+
+	/* Exit instantly with error when device is not ready
+	 * to receive scan abort command or it does not perform
+	 * hardware scan currently */
+	if (!test_bit(STATUS_READY, &priv->status) ||
+	    !test_bit(STATUS_SCAN_HW, &priv->status) ||
+	    test_bit(STATUS_FW_ERROR, &priv->status))
+		return -EIO;
+
+	ret = iwl_dvm_send_cmd(priv, &cmd);
+	if (ret)
+		return ret;
+
+	status = (void *)cmd.resp_pkt->data;
+	if (*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_SCAN(priv, "SCAN_ABORT ret %d.\n",
+			       le32_to_cpu(*status));
+		ret = -EIO;
+	}
+
+	iwl_free_resp(&cmd);
+	return ret;
+}
+
+static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
+{
+	struct cfg80211_scan_info info = {
+		.aborted = aborted,
+	};
+
+	/* check if scan was requested from mac80211 */
+	if (priv->scan_request) {
+		IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
+		ieee80211_scan_completed(priv->hw, &info);
+	}
+
+	priv->scan_type = IWL_SCAN_NORMAL;
+	priv->scan_vif = NULL;
+	priv->scan_request = NULL;
+}
+
+static void iwl_process_scan_complete(struct iwl_priv *priv)
+{
+	bool aborted;
+
+	lockdep_assert_held(&priv->mutex);
+
+	if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
+		return;
+
+	IWL_DEBUG_SCAN(priv, "Completed scan.\n");
+
+	cancel_delayed_work(&priv->scan_check);
+
+	aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
+	if (aborted)
+		IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
+
+	if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
+		IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
+		goto out_settings;
+	}
+
+	if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
+		int err;
+
+		/* Check if mac80211 requested scan during our internal scan */
+		if (priv->scan_request == NULL)
+			goto out_complete;
+
+		/* If so request a new scan */
+		err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
+					priv->scan_request->channels[0]->band);
+		if (err) {
+			IWL_DEBUG_SCAN(priv,
+				"failed to initiate pending scan: %d\n", err);
+			aborted = true;
+			goto out_complete;
+		}
+
+		return;
+	}
+
+out_complete:
+	iwl_complete_scan(priv, aborted);
+
+out_settings:
+	/* Can we still talk to firmware ? */
+	if (!iwl_is_ready_rf(priv))
+		return;
+
+	iwlagn_post_scan(priv);
+}
+
+void iwl_force_scan_end(struct iwl_priv *priv)
+{
+	lockdep_assert_held(&priv->mutex);
+
+	if (!test_bit(STATUS_SCANNING, &priv->status)) {
+		IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
+		return;
+	}
+
+	IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
+	clear_bit(STATUS_SCANNING, &priv->status);
+	clear_bit(STATUS_SCAN_HW, &priv->status);
+	clear_bit(STATUS_SCAN_ABORTING, &priv->status);
+	clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
+	iwl_complete_scan(priv, true);
+}
+
+static void iwl_do_scan_abort(struct iwl_priv *priv)
+{
+	int ret;
+
+	lockdep_assert_held(&priv->mutex);
+
+	if (!test_bit(STATUS_SCANNING, &priv->status)) {
+		IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
+		return;
+	}
+
+	if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
+		IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
+		return;
+	}
+
+	ret = iwl_send_scan_abort(priv);
+	if (ret) {
+		IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
+		iwl_force_scan_end(priv);
+	} else
+		IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
+}
+
+/**
+ * iwl_scan_cancel - Cancel any currently executing HW scan
+ */
+int iwl_scan_cancel(struct iwl_priv *priv)
+{
+	IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
+	queue_work(priv->workqueue, &priv->abort_scan);
+	return 0;
+}
+
+/**
+ * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
+ * @ms: amount of time to wait (in milliseconds) for scan to abort
+ *
+ */
+void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(ms);
+
+	lockdep_assert_held(&priv->mutex);
+
+	IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
+
+	iwl_do_scan_abort(priv);
+
+	while (time_before_eq(jiffies, timeout)) {
+		if (!test_bit(STATUS_SCAN_HW, &priv->status))
+			goto finished;
+		msleep(20);
+	}
+
+	return;
+
+ finished:
+	/*
+	 * Now STATUS_SCAN_HW is clear. This means that the
+	 * device finished, but the background work is going
+	 * to execute at best as soon as we release the mutex.
+	 * Since we need to be able to issue a new scan right
+	 * after this function returns, run the complete here.
+	 * The STATUS_SCAN_COMPLETE bit will then be cleared
+	 * and prevent the background work from "completing"
+	 * a possible new scan.
+	 */
+	iwl_process_scan_complete(priv);
+}
+
+/* Service response to REPLY_SCAN_CMD (0x80) */
+static void iwl_rx_reply_scan(struct iwl_priv *priv,
+			      struct iwl_rx_cmd_buffer *rxb)
+{
+#ifdef CONFIG_IWLWIFI_DEBUG
+	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	struct iwl_scanreq_notification *notif = (void *)pkt->data;
+
+	IWL_DEBUG_SCAN(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_cmd_buffer *rxb)
+{
+	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	struct iwl_scanstart_notification *notif = (void *)pkt->data;
+
+	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_cmd_buffer *rxb)
+{
+#ifdef CONFIG_IWLWIFI_DEBUG
+	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	struct iwl_scanresults_notification *notif = (void *)pkt->data;
+
+	IWL_DEBUG_SCAN(priv, "Scan ch.res: "
+		       "%d [802.11%s] "
+		       "probe status: %u:%u "
+		       "(TSF: 0x%08X:%08X) - %d "
+		       "elapsed=%lu usec\n",
+		       notif->channel,
+		       notif->band ? "bg" : "a",
+		       notif->probe_status, notif->num_probe_not_sent,
+		       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_cmd_buffer *rxb)
+{
+	struct iwl_rx_packet *pkt = rxb_addr(rxb);
+	struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
+
+	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);
+
+	IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
+		       (priv->scan_band == NL80211_BAND_2GHZ) ? "2.4" : "5.2",
+		       jiffies_to_msecs(jiffies - priv->scan_start));
+
+	/*
+	 * When aborting, we run the scan completed background work inline
+	 * and the background work must then do nothing. The SCAN_COMPLETE
+	 * bit helps implement that logic and thus needs to be set before
+	 * queueing the work. Also, since the scan abort waits for SCAN_HW
+	 * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
+	 * to avoid a race there.
+	 */
+	set_bit(STATUS_SCAN_COMPLETE, &priv->status);
+	clear_bit(STATUS_SCAN_HW, &priv->status);
+	queue_work(priv->workqueue, &priv->scan_completed);
+
+	if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
+	    iwl_advanced_bt_coexist(priv) &&
+	    priv->bt_status != scan_notif->bt_status) {
+		if (scan_notif->bt_status) {
+			/* BT on */
+			if (!priv->bt_ch_announce)
+				priv->bt_traffic_load =
+					IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
+			/*
+			 * otherwise, no traffic load information provided
+			 * no changes made
+			 */
+		} else {
+			/* BT off */
+			priv->bt_traffic_load =
+				IWL_BT_COEX_TRAFFIC_LOAD_NONE;
+		}
+		priv->bt_status = scan_notif->bt_status;
+		queue_work(priv->workqueue,
+			   &priv->bt_traffic_change_work);
+	}
+}
+
+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;
+}
+
+static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
+				     enum nl80211_band band, u8 n_probes)
+{
+	if (band == NL80211_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);
+}
+
+static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
+{
+	struct iwl_rxon_context *ctx;
+	int limits[NUM_IWL_RXON_CTX] = {};
+	int n_active = 0;
+	u16 limit;
+
+	BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);
+
+	/*
+	 * If we're associated, we clamp the dwell time 98%
+	 * of the beacon interval (minus 2 * channel tune time)
+	 * If both contexts are active, we have to restrict to
+	 * 1/2 of the minimum of them, because they might be in
+	 * lock-step with the time inbetween only half of what
+	 * time we'd have in each of them.
+	 */
+	for_each_context(priv, ctx) {
+		switch (ctx->staging.dev_type) {
+		case RXON_DEV_TYPE_P2P:
+			/* no timing constraints */
+			continue;
+		case RXON_DEV_TYPE_ESS:
+		default:
+			/* timing constraints if associated */
+			if (!iwl_is_associated_ctx(ctx))
+				continue;
+			break;
+		case RXON_DEV_TYPE_CP:
+		case RXON_DEV_TYPE_2STA:
+			/*
+			 * These seem to always have timers for TBTT
+			 * active in uCode even when not associated yet.
+			 */
+			break;
+		}
+
+		limits[n_active++] = ctx->beacon_int ?: IWL_PASSIVE_DWELL_BASE;
+	}
+
+	switch (n_active) {
+	case 0:
+		return dwell_time;
+	case 2:
+		limit = (limits[1] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
+		limit /= 2;
+		dwell_time = min(limit, dwell_time);
+		/* fall through to limit further */
+	case 1:
+		limit = (limits[0] * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
+		limit /= n_active;
+		return min(limit, dwell_time);
+	default:
+		WARN_ON_ONCE(1);
+		return dwell_time;
+	}
+}
+
+static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
+				      enum nl80211_band band)
+{
+	u16 passive = (band == NL80211_BAND_2GHZ) ?
+	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
+	    IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
+
+	return iwl_limit_dwell(priv, passive);
+}
+
+/* Return valid, unused, channel for a passive scan to reset the RF */
+static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
+					enum nl80211_band band)
+{
+	struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
+	struct iwl_rxon_context *ctx;
+	int i;
+
+	for (i = 0; i < sband->n_channels; i++) {
+		bool busy = false;
+
+		for_each_context(priv, ctx) {
+			busy = sband->channels[i].hw_value ==
+				le16_to_cpu(ctx->staging.channel);
+			if (busy)
+				break;
+		}
+
+		if (busy)
+			continue;
+
+		if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
+			return sband->channels[i].hw_value;
+	}
+
+	return 0;
+}
+
+static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
+					  struct ieee80211_vif *vif,
+					  enum nl80211_band band,
+					  struct iwl_scan_channel *scan_ch)
+{
+	const struct ieee80211_supported_band *sband;
+	u16 channel;
+
+	sband = iwl_get_hw_mode(priv, band);
+	if (!sband) {
+		IWL_ERR(priv, "invalid band\n");
+		return 0;
+	}
+
+	channel = iwl_get_single_channel_number(priv, band);
+	if (channel) {
+		scan_ch->channel = cpu_to_le16(channel);
+		scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
+		scan_ch->active_dwell =
+			cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
+		scan_ch->passive_dwell =
+			cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
+		/* Set txpower levels to defaults */
+		scan_ch->dsp_atten = 110;
+		if (band == NL80211_BAND_5GHZ)
+			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
+		else
+			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
+		return 1;
+	}
+
+	IWL_ERR(priv, "no valid channel found\n");
+	return 0;
+}
+
+static int iwl_get_channels_for_scan(struct iwl_priv *priv,
+				     struct ieee80211_vif *vif,
+				     enum nl80211_band band,
+				     u8 is_active, u8 n_probes,
+				     struct iwl_scan_channel *scan_ch)
+{
+	struct ieee80211_channel *chan;
+	const struct ieee80211_supported_band *sband;
+	u16 passive_dwell = 0;
+	u16 active_dwell = 0;
+	int added, i;
+	u16 channel;
+
+	sband = iwl_get_hw_mode(priv, band);
+	if (!sband)
+		return 0;
+
+	active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
+	passive_dwell = iwl_get_passive_dwell_time(priv, band);
+
+	if (passive_dwell <= active_dwell)
+		passive_dwell = active_dwell + 1;
+
+	for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
+		chan = priv->scan_request->channels[i];
+
+		if (chan->band != band)
+			continue;
+
+		channel = chan->hw_value;
+		scan_ch->channel = cpu_to_le16(channel);
+
+		if (!is_active || (chan->flags & IEEE80211_CHAN_NO_IR))
+			scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
+		else
+			scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
+
+		if (n_probes)
+			scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
+
+		scan_ch->active_dwell = cpu_to_le16(active_dwell);
+		scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
+
+		/* Set txpower levels to defaults */
+		scan_ch->dsp_atten = 110;
+
+		/* NOTE: if we were doing 6Mb OFDM for scans we'd use
+		 * power level:
+		 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
+		 */
+		if (band == NL80211_BAND_5GHZ)
+			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
+		else
+			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
+
+		IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
+			       channel, le32_to_cpu(scan_ch->type),
+			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
+				"ACTIVE" : "PASSIVE",
+			       (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
+			       active_dwell : passive_dwell);
+
+		scan_ch++;
+		added++;
+	}
+
+	IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
+	return added;
+}
+
+/**
+ * iwl_fill_probe_req - fill in all required fields and IE for probe request
+ */
+
+static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
+			      const u8 *ies, int ie_len, const u8 *ssid,
+			      u8 ssid_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);
+	eth_broadcast_addr(frame->da);
+	memcpy(frame->sa, ta, ETH_ALEN);
+	eth_broadcast_addr(frame->bssid);
+	frame->seq_ctrl = 0;
+
+	len += 24;
+
+	/* ...next IE... */
+	pos = &frame->u.probe_req.variable[0];
+
+	/* fill in our SSID IE */
+	left -= ssid_len + 2;
+	if (left < 0)
+		return 0;
+	*pos++ = WLAN_EID_SSID;
+	*pos++ = ssid_len;
+	if (ssid && ssid_len) {
+		memcpy(pos, ssid, ssid_len);
+		pos += ssid_len;
+	}
+
+	len += ssid_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;
+}
+
+static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
+{
+	struct iwl_host_cmd cmd = {
+		.id = REPLY_SCAN_CMD,
+		.len = { sizeof(struct iwl_scan_cmd), },
+	};
+	struct iwl_scan_cmd *scan;
+	struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
+	u32 rate_flags = 0;
+	u16 cmd_len = 0;
+	u16 rx_chain = 0;
+	enum nl80211_band band;
+	u8 n_probes = 0;
+	u8 rx_ant = priv->nvm_data->valid_rx_ant;
+	u8 rate;
+	bool is_active = false;
+	int  chan_mod;
+	u8 active_chains;
+	u8 scan_tx_antennas = priv->nvm_data->valid_tx_ant;
+	int ret;
+	int scan_cmd_size = sizeof(struct iwl_scan_cmd) +
+			    MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
+			    priv->fw->ucode_capa.max_probe_length;
+	const u8 *ssid = NULL;
+	u8 ssid_len = 0;
+
+	if (WARN_ON(priv->scan_type == IWL_SCAN_NORMAL &&
+		    (!priv->scan_request ||
+		     priv->scan_request->n_channels > MAX_SCAN_CHANNEL)))
+		return -EINVAL;
+
+	lockdep_assert_held(&priv->mutex);
+
+	if (vif)
+		ctx = iwl_rxon_ctx_from_vif(vif);
+
+	if (!priv->scan_cmd) {
+		priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
+		if (!priv->scan_cmd) {
+			IWL_DEBUG_SCAN(priv,
+				       "fail to allocate memory for scan\n");
+			return -ENOMEM;
+		}
+	}
+	scan = priv->scan_cmd;
+	memset(scan, 0, scan_cmd_size);
+
+	scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
+	scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
+
+	if (iwl_is_any_associated(priv)) {
+		u16 interval = 0;
+		u32 extra;
+		u32 suspend_time = 100;
+		u32 scan_suspend_time = 100;
+
+		IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
+		switch (priv->scan_type) {
+		case IWL_SCAN_RADIO_RESET:
+			interval = 0;
+			break;
+		case IWL_SCAN_NORMAL:
+			interval = vif->bss_conf.beacon_int;
+			break;
+		}
+
+		scan->suspend_time = 0;
+		scan->max_out_time = cpu_to_le32(200 * 1024);
+		if (!interval)
+			interval = suspend_time;
+
+		extra = (suspend_time / interval) << 22;
+		scan_suspend_time = (extra |
+		    ((suspend_time % interval) * 1024));
+		scan->suspend_time = cpu_to_le32(scan_suspend_time);
+		IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
+			       scan_suspend_time, interval);
+	}
+
+	switch (priv->scan_type) {
+	case IWL_SCAN_RADIO_RESET:
+		IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
+		/*
+		 * Override quiet time as firmware checks that active
+		 * dwell is >= quiet; since we use passive scan it'll
+		 * not actually be used.
+		 */
+		scan->quiet_time = cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
+		break;
+	case IWL_SCAN_NORMAL:
+		if (priv->scan_request->n_ssids) {
+			int i, p = 0;
+			IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
+			/*
+			 * The highest priority SSID is inserted to the
+			 * probe request template.
+			 */
+			ssid_len = priv->scan_request->ssids[0].ssid_len;
+			ssid = priv->scan_request->ssids[0].ssid;
+
+			/*
+			 * Invert the order of ssids, the firmware will invert
+			 * it back.
+			 */
+			for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
+				scan->direct_scan[p].id = WLAN_EID_SSID;
+				scan->direct_scan[p].len =
+					priv->scan_request->ssids[i].ssid_len;
+				memcpy(scan->direct_scan[p].ssid,
+				       priv->scan_request->ssids[i].ssid,
+				       priv->scan_request->ssids[i].ssid_len);
+				n_probes++;
+				p++;
+			}
+			is_active = true;
+		} else
+			IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
+		break;
+	}
+
+	scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
+	scan->tx_cmd.sta_id = ctx->bcast_sta_id;
+	scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
+
+	switch (priv->scan_band) {
+	case NL80211_BAND_2GHZ:
+		scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
+		chan_mod = le32_to_cpu(
+			priv->contexts[IWL_RXON_CTX_BSS].active.flags &
+						RXON_FLG_CHANNEL_MODE_MSK)
+				       >> RXON_FLG_CHANNEL_MODE_POS;
+		if ((priv->scan_request && priv->scan_request->no_cck) ||
+		    chan_mod == CHANNEL_MODE_PURE_40) {
+			rate = IWL_RATE_6M_PLCP;
+		} else {
+			rate = IWL_RATE_1M_PLCP;
+			rate_flags = RATE_MCS_CCK_MSK;
+		}
+		/*
+		 * Internal scans are passive, so we can indiscriminately set
+		 * the BT ignore flag on 2.4 GHz since it applies to TX only.
+		 */
+		if (priv->lib->bt_params &&
+		    priv->lib->bt_params->advanced_bt_coexist)
+			scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
+		break;
+	case NL80211_BAND_5GHZ:
+		rate = IWL_RATE_6M_PLCP;
+		break;
+	default:
+		IWL_WARN(priv, "Invalid scan band\n");
+		return -EIO;
+	}
+
+	/*
+	 * If active scanning is requested but a certain channel is
+	 * marked passive, we can do active scanning if we detect
+	 * transmissions.
+	 *
+	 * There is an issue with some firmware versions that triggers
+	 * a sysassert on a "good CRC threshold" of zero (== disabled),
+	 * on a radar channel even though this means that we should NOT
+	 * send probes.
+	 *
+	 * The "good CRC threshold" is the number of frames that we
+	 * need to receive during our dwell time on a channel before
+	 * sending out probes -- setting this to a huge value will
+	 * mean we never reach it, but at the same time work around
+	 * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
+	 * here instead of IWL_GOOD_CRC_TH_DISABLED.
+	 *
+	 * This was fixed in later versions along with some other
+	 * scan changes, and the threshold behaves as a flag in those
+	 * versions.
+	 */
+	if (priv->new_scan_threshold_behaviour)
+		scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
+						IWL_GOOD_CRC_TH_DISABLED;
+	else
+		scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
+						IWL_GOOD_CRC_TH_NEVER;
+
+	band = priv->scan_band;
+
+	if (band == NL80211_BAND_2GHZ &&
+	    priv->lib->bt_params &&
+	    priv->lib->bt_params->advanced_bt_coexist) {
+		/* transmit 2.4 GHz probes only on first antenna */
+		scan_tx_antennas = first_antenna(scan_tx_antennas);
+	}
+
+	priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
+						    priv->scan_tx_ant[band],
+						    scan_tx_antennas);
+	rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
+	scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
+
+	/*
+	 * In power save mode while associated use one chain,
+	 * otherwise use all chains
+	 */
+	if (test_bit(STATUS_POWER_PMI, &priv->status) &&
+	    !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
+		/* rx_ant has been set to all valid chains previously */
+		active_chains = rx_ant &
+				((u8)(priv->chain_noise_data.active_chains));
+		if (!active_chains)
+			active_chains = rx_ant;
+
+		IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
+				priv->chain_noise_data.active_chains);
+
+		rx_ant = first_antenna(active_chains);
+	}
+	if (priv->lib->bt_params &&
+	    priv->lib->bt_params->advanced_bt_coexist &&
+	    priv->bt_full_concurrent) {
+		/* operated as 1x1 in full concurrency mode */
+		rx_ant = first_antenna(rx_ant);
+	}
+
+	/* MIMO is not used here, but value is required */
+	rx_chain |=
+		priv->nvm_data->valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
+	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
+	rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
+	rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
+	scan->rx_chain = cpu_to_le16(rx_chain);
+	switch (priv->scan_type) {
+	case IWL_SCAN_NORMAL:
+		cmd_len = iwl_fill_probe_req(
+					(struct ieee80211_mgmt *)scan->data,
+					vif->addr,
+					priv->scan_request->ie,
+					priv->scan_request->ie_len,
+					ssid, ssid_len,
+					scan_cmd_size - sizeof(*scan));
+		break;
+	case IWL_SCAN_RADIO_RESET:
+		/* use bcast addr, will not be transmitted but must be valid */
+		cmd_len = iwl_fill_probe_req(
+					(struct ieee80211_mgmt *)scan->data,
+					iwl_bcast_addr, NULL, 0,
+					NULL, 0,
+					scan_cmd_size - sizeof(*scan));
+		break;
+	default:
+		BUG();
+	}
+	scan->tx_cmd.len = cpu_to_le16(cmd_len);
+
+	scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
+			       RXON_FILTER_BCON_AWARE_MSK);
+
+	switch (priv->scan_type) {
+	case IWL_SCAN_RADIO_RESET:
+		scan->channel_count =
+			iwl_get_channel_for_reset_scan(priv, vif, band,
+				(void *)&scan->data[cmd_len]);
+		break;
+	case IWL_SCAN_NORMAL:
+		scan->channel_count =
+			iwl_get_channels_for_scan(priv, vif, band,
+				is_active, n_probes,
+				(void *)&scan->data[cmd_len]);
+		break;
+	}
+
+	if (scan->channel_count == 0) {
+		IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
+		return -EIO;
+	}
+
+	cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
+	    scan->channel_count * sizeof(struct iwl_scan_channel);
+	cmd.data[0] = scan;
+	cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
+	scan->len = cpu_to_le16(cmd.len[0]);
+
+	/* set scan bit here for PAN params */
+	set_bit(STATUS_SCAN_HW, &priv->status);
+
+	ret = iwlagn_set_pan_params(priv);
+	if (ret) {
+		clear_bit(STATUS_SCAN_HW, &priv->status);
+		return ret;
+	}
+
+	ret = iwl_dvm_send_cmd(priv, &cmd);
+	if (ret) {
+		clear_bit(STATUS_SCAN_HW, &priv->status);
+		iwlagn_set_pan_params(priv);
+	}
+
+	return ret;
+}
+
+void iwl_init_scan_params(struct iwl_priv *priv)
+{
+	u8 ant_idx = fls(priv->nvm_data->valid_tx_ant) - 1;
+	if (!priv->scan_tx_ant[NL80211_BAND_5GHZ])
+		priv->scan_tx_ant[NL80211_BAND_5GHZ] = ant_idx;
+	if (!priv->scan_tx_ant[NL80211_BAND_2GHZ])
+		priv->scan_tx_ant[NL80211_BAND_2GHZ] = ant_idx;
+}
+
+int __must_check iwl_scan_initiate(struct iwl_priv *priv,
+				   struct ieee80211_vif *vif,
+				   enum iwl_scan_type scan_type,
+				   enum nl80211_band band)
+{
+	int ret;
+
+	lockdep_assert_held(&priv->mutex);
+
+	cancel_delayed_work(&priv->scan_check);
+
+	if (!iwl_is_ready_rf(priv)) {
+		IWL_WARN(priv, "Request scan called when driver not ready.\n");
+		return -EIO;
+	}
+
+	if (test_bit(STATUS_SCAN_HW, &priv->status)) {
+		IWL_DEBUG_SCAN(priv,
+			"Multiple concurrent scan requests in parallel.\n");
+		return -EBUSY;
+	}
+
+	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
+		IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
+		return -EBUSY;
+	}
+
+	IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
+			scan_type == IWL_SCAN_NORMAL ? "" :
+			"internal short ");
+
+	set_bit(STATUS_SCANNING, &priv->status);
+	priv->scan_type = scan_type;
+	priv->scan_start = jiffies;
+	priv->scan_band = band;
+
+	ret = iwlagn_request_scan(priv, vif);
+	if (ret) {
+		clear_bit(STATUS_SCANNING, &priv->status);
+		priv->scan_type = IWL_SCAN_NORMAL;
+		return ret;
+	}
+
+	queue_delayed_work(priv->workqueue, &priv->scan_check,
+			   IWL_SCAN_CHECK_WATCHDOG);
+
+	return 0;
+}
+
+
+/*
+ * 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);
+}
+
+static void iwl_bg_start_internal_scan(struct work_struct *work)
+{
+	struct iwl_priv *priv =
+		container_of(work, struct iwl_priv, start_internal_scan);
+
+	IWL_DEBUG_SCAN(priv, "Start internal scan\n");
+
+	mutex_lock(&priv->mutex);
+
+	if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
+		IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
+		goto unlock;
+	}
+
+	if (test_bit(STATUS_SCANNING, &priv->status)) {
+		IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
+		goto unlock;
+	}
+
+	if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
+		IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
+ unlock:
+	mutex_unlock(&priv->mutex);
+}
+
+static void iwl_bg_scan_check(struct work_struct *data)
+{
+	struct iwl_priv *priv =
+	    container_of(data, struct iwl_priv, scan_check.work);
+
+	IWL_DEBUG_SCAN(priv, "Scan check work\n");
+
+	/* Since we are here firmware does not finish scan and
+	 * most likely is in bad shape, so we don't bother to
+	 * send abort command, just force scan complete to mac80211 */
+	mutex_lock(&priv->mutex);
+	iwl_force_scan_end(priv);
+	mutex_unlock(&priv->mutex);
+}
+
+static void iwl_bg_abort_scan(struct work_struct *work)
+{
+	struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
+
+	IWL_DEBUG_SCAN(priv, "Abort scan work\n");
+
+	/* We keep scan_check work queued in case when firmware will not
+	 * report back scan completed notification */
+	mutex_lock(&priv->mutex);
+	iwl_scan_cancel_timeout(priv, 200);
+	mutex_unlock(&priv->mutex);
+}
+
+static void iwl_bg_scan_completed(struct work_struct *work)
+{
+	struct iwl_priv *priv =
+		container_of(work, struct iwl_priv, scan_completed);
+
+	mutex_lock(&priv->mutex);
+	iwl_process_scan_complete(priv);
+	mutex_unlock(&priv->mutex);
+}
+
+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);
+}
+
+void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
+{
+	cancel_work_sync(&priv->start_internal_scan);
+	cancel_work_sync(&priv->abort_scan);
+	cancel_work_sync(&priv->scan_completed);
+
+	if (cancel_delayed_work_sync(&priv->scan_check)) {
+		mutex_lock(&priv->mutex);
+		iwl_force_scan_end(priv);
+		mutex_unlock(&priv->mutex);
+	}
+}