Merge branch 'linus' into cpus4096-for-linus

Conflicts:

	net/sunrpc/svc.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 931 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c
new file mode 100644
index 000000000000..efc750d2fc5c
--- /dev/null
+++ b/drivers/net/wireless/iwlwifi/iwl-scan.c
@@ -0,0 +1,931 @@
+/******************************************************************************
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2008 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:
+ * Tomas Winkler <tomas.winkler@intel.com>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ *****************************************************************************/
+#include <net/mac80211.h>
+#include <linux/etherdevice.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 faster active scanning, scan will move to the next channel if fewer than
+ * PLCP_QUIET_THRESH packets are heard on this channel within
+ * ACTIVE_QUIET_TIME after sending probe request.  This shortens the dwell
+ * time if it's a quiet channel (nothing responded to our probe, and there's
+ * no other traffic).
+ * Disable "quiet" feature by setting PLCP_QUIET_THRESH to 0. */
+#define IWL_PLCP_QUIET_THRESH       __constant_cpu_to_le16(1)  /* packets */
+#define IWL_ACTIVE_QUIET_TIME       __constant_cpu_to_le16(10)  /* msec */
+
+/* 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 IWL_SCAN_PROBE_MASK(n) 	cpu_to_le32((BIT(n) | (BIT(n) - BIT(1))))
+
+
+static int scan_tx_ant[3] = {
+	RATE_MCS_ANT_A_MSK, RATE_MCS_ANT_B_MSK, RATE_MCS_ANT_C_MSK
+};
+
+
+
+static int iwl_is_empty_essid(const char *essid, int essid_len)
+{
+	/* Single white space is for Linksys APs */
+	if (essid_len == 1 && essid[0] == ' ')
+		return 1;
+
+	/* Otherwise, if the entire essid is 0, we assume it is hidden */
+	while (essid_len) {
+		essid_len--;
+		if (essid[essid_len] != '\0')
+			return 0;
+	}
+
+	return 1;
+}
+
+
+
+const char *iwl_escape_essid(const char *essid, u8 essid_len)
+{
+	static char escaped[IW_ESSID_MAX_SIZE * 2 + 1];
+	const char *s = essid;
+	char *d = escaped;
+
+	if (iwl_is_empty_essid(essid, essid_len)) {
+		memcpy(escaped, "<hidden>", sizeof("<hidden>"));
+		return escaped;
+	}
+
+	essid_len = min(essid_len, (u8) IW_ESSID_MAX_SIZE);
+	while (essid_len--) {
+		if (*s == '\0') {
+			*d++ = '\\';
+			*d++ = '0';
+			s++;
+		} else
+			*d++ = *s++;
+	}
+	*d = '\0';
+	return escaped;
+}
+EXPORT_SYMBOL(iwl_escape_essid);
+
+/**
+ * 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_bit(STATUS_SCAN_ABORTING, &priv->status)) {
+			IWL_DEBUG_SCAN("Queuing scan abort.\n");
+			set_bit(STATUS_SCAN_ABORTING, &priv->status);
+			queue_work(priv->workqueue, &priv->abort_scan);
+
+		} else
+			IWL_DEBUG_SCAN("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 *res;
+	struct iwl_host_cmd cmd = {
+		.id = REPLY_SCAN_ABORT_CMD,
+		.meta.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;
+	}
+
+	res = (struct iwl_rx_packet *)cmd.meta.u.skb->data;
+	if (res->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("SCAN_ABORT returned %d.\n", res->u.status);
+		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
+		clear_bit(STATUS_SCAN_HW, &priv->status);
+	}
+
+	dev_kfree_skb_any(cmd.meta.u.skb);
+
+	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 = (struct iwl_rx_packet *)rxb->skb->data;
+	struct iwl_scanreq_notification *notif =
+	    (struct iwl_scanreq_notification *)pkt->u.raw;
+
+	IWL_DEBUG_RX("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 = (struct iwl_rx_packet *)rxb->skb->data;
+	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("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 = (struct iwl_rx_packet *)rxb->skb->data;
+	struct iwl_scanresults_notification *notif =
+	    (struct iwl_scanresults_notification *)pkt->u.raw;
+
+	IWL_DEBUG_SCAN("Scan ch.res: "
+		       "%d [802.11%s] "
+		       "(TSF: 0x%08X:%08X) - %d "
+		       "elapsed=%lu usec (%dms since last)\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,
+		       jiffies_to_msecs(elapsed_jiffies
+					(priv->last_scan_jiffies, jiffies)));
+#endif
+
+	priv->last_scan_jiffies = jiffies;
+	priv->next_scan_jiffies = 0;
+}
+
+/* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
+static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
+				       struct iwl_rx_mem_buffer *rxb)
+{
+	struct iwl_rx_packet *pkt = (struct iwl_rx_packet *)rxb->skb->data;
+	struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
+
+	IWL_DEBUG_SCAN("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);
+
+	/* The HW is no longer scanning */
+	clear_bit(STATUS_SCAN_HW, &priv->status);
+
+	/* The scan completion notification came in, so kill that timer... */
+	cancel_delayed_work(&priv->scan_check);
+
+	IWL_DEBUG_INFO("Scan pass on %sGHz took %dms\n",
+		       (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
+						"2.4" : "5.2",
+		       jiffies_to_msecs(elapsed_jiffies
+					(priv->scan_pass_start, jiffies)));
+
+	/* Remove this scanned band from the list of pending
+	 * bands to scan, band G precedes A in order of scanning
+	 * as seen in iwl_bg_request_scan */
+	if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
+		priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
+	else if (priv->scan_bands &  BIT(IEEE80211_BAND_5GHZ))
+		priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
+
+	/* 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_bit(STATUS_SCAN_ABORTING, &priv->status)) {
+		IWL_DEBUG_INFO("Aborted scan completed.\n");
+		clear_bit(STATUS_SCAN_ABORTING, &priv->status);
+	} else {
+		/* If there are more bands on this scan pass reschedule */
+		if (priv->scan_bands)
+			goto reschedule;
+	}
+
+	priv->last_scan_jiffies = jiffies;
+	priv->next_scan_jiffies = 0;
+	IWL_DEBUG_INFO("Setting scan to off\n");
+
+	clear_bit(STATUS_SCANNING, &priv->status);
+
+	IWL_DEBUG_INFO("Scan took %dms\n",
+		jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
+
+	queue_work(priv->workqueue, &priv->scan_completed);
+
+	return;
+
+reschedule:
+	priv->scan_pass_start = jiffies;
+	queue_work(priv->workqueue, &priv->request_scan);
+}
+
+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);
+
+static 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);
+}
+
+static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
+				      enum ieee80211_band band)
+{
+	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 = priv->beacon_int;
+		if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
+			passive = IWL_PASSIVE_DWELL_BASE;
+		passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
+	}
+
+	return passive;
+}
+
+static int iwl_get_channels_for_scan(struct iwl_priv *priv,
+				     enum ieee80211_band band,
+				     u8 is_active, u8 n_probes,
+				     struct iwl_scan_channel *scan_ch)
+{
+	const struct ieee80211_channel *channels = NULL;
+	const struct ieee80211_supported_band *sband;
+	const struct iwl_channel_info *ch_info;
+	u16 passive_dwell = 0;
+	u16 active_dwell = 0;
+	int added, i;
+	u16 channel;
+
+	sband = iwl_get_hw_mode(priv, band);
+	if (!sband)
+		return 0;
+
+	channels = sband->channels;
+
+	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 < sband->n_channels; i++) {
+		if (channels[i].flags & IEEE80211_CHAN_DISABLED)
+			continue;
+
+		channel =
+			ieee80211_frequency_to_channel(channels[i].center_freq);
+		scan_ch->channel = cpu_to_le16(channel);
+
+		ch_info = iwl_get_channel_info(priv, band, channel);
+		if (!is_channel_valid(ch_info)) {
+			IWL_DEBUG_SCAN("Channel %d is INVALID for this band.\n",
+					channel);
+			continue;
+		}
+
+		if (!is_active || is_channel_passive(ch_info) ||
+		    (channels[i].flags & IEEE80211_CHAN_PASSIVE_SCAN))
+			scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
+		else
+			scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
+
+		if ((scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) && 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 == IEEE80211_BAND_5GHZ)
+			scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
+		else
+			scan_ch->tx_gain = ((1 << 5) | (5 << 3));
+
+		IWL_DEBUG_SCAN("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("total channels to scan %d \n", added);
+	return added;
+}
+
+void iwl_init_scan_params(struct iwl_priv *priv)
+{
+	if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
+		priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = RATE_MCS_ANT_INIT_IND;
+	if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
+		priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = RATE_MCS_ANT_INIT_IND;
+}
+
+int iwl_scan_initiate(struct iwl_priv *priv)
+{
+	if (priv->iw_mode == IEEE80211_IF_TYPE_AP) {
+		IWL_ERROR("APs don't scan.\n");
+		return 0;
+	}
+
+	if (!iwl_is_ready_rf(priv)) {
+		IWL_DEBUG_SCAN("Aborting scan due to not ready.\n");
+		return -EIO;
+	}
+
+	if (test_bit(STATUS_SCANNING, &priv->status)) {
+		IWL_DEBUG_SCAN("Scan already in progress.\n");
+		return -EAGAIN;
+	}
+
+	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
+		IWL_DEBUG_SCAN("Scan request while abort pending.  "
+			       "Queuing.\n");
+		return -EAGAIN;
+	}
+
+	IWL_DEBUG_INFO("Starting scan...\n");
+	if (priv->cfg->sku & IWL_SKU_G)
+		priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
+	if (priv->cfg->sku & IWL_SKU_A)
+		priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
+	set_bit(STATUS_SCANNING, &priv->status);
+	priv->scan_start = jiffies;
+	priv->scan_pass_start = priv->scan_start;
+
+	queue_work(priv->workqueue, &priv->request_scan);
+
+	return 0;
+}
+EXPORT_SYMBOL(iwl_scan_initiate);
+
+#define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
+
+static 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(IWL_DL_SCAN, "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);
+}
+/**
+ * iwl_supported_rate_to_ie - fill in the supported rate in IE field
+ *
+ * return : set the bit for each supported rate insert in ie
+ */
+static u16 iwl_supported_rate_to_ie(u8 *ie, u16 supported_rate,
+				    u16 basic_rate, int *left)
+{
+	u16 ret_rates = 0, bit;
+	int i;
+	u8 *cnt = ie;
+	u8 *rates = ie + 1;
+
+	for (bit = 1, i = 0; i < IWL_RATE_COUNT; i++, bit <<= 1) {
+		if (bit & supported_rate) {
+			ret_rates |= bit;
+			rates[*cnt] = iwl_rates[i].ieee |
+				((bit & basic_rate) ? 0x80 : 0x00);
+			(*cnt)++;
+			(*left)--;
+			if ((*left <= 0) ||
+			    (*cnt >= IWL_SUPPORTED_RATES_IE_LEN))
+				break;
+		}
+	}
+
+	return ret_rates;
+}
+
+
+static void iwl_ht_cap_to_ie(const struct ieee80211_supported_band *sband,
+			     u8 *pos, int *left)
+{
+	struct ieee80211_ht_cap *ht_cap;
+
+	if (!sband || !sband->ht_info.ht_supported)
+		return;
+
+	if (*left < sizeof(struct ieee80211_ht_cap))
+		return;
+
+	*pos++ = sizeof(struct ieee80211_ht_cap);
+	ht_cap = (struct ieee80211_ht_cap *) pos;
+
+	ht_cap->cap_info = cpu_to_le16(sband->ht_info.cap);
+	memcpy(ht_cap->supp_mcs_set, sband->ht_info.supp_mcs_set, 16);
+	ht_cap->ampdu_params_info =
+		(sband->ht_info.ampdu_factor & IEEE80211_HT_CAP_AMPDU_FACTOR) |
+		((sband->ht_info.ampdu_density << 2) &
+			IEEE80211_HT_CAP_AMPDU_DENSITY);
+	*left -= sizeof(struct ieee80211_ht_cap);
+}
+
+/**
+ * iwl_fill_probe_req - fill in all required fields and IE for probe request
+ */
+
+static u16 iwl_fill_probe_req(struct iwl_priv *priv,
+				  enum ieee80211_band band,
+				  struct ieee80211_mgmt *frame,
+				  int left)
+{
+	int len = 0;
+	u8 *pos = NULL;
+	u16 active_rates, ret_rates, cck_rates, active_rate_basic;
+	const struct ieee80211_supported_band *sband =
+						iwl_get_hw_mode(priv, band);
+
+
+	/* 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, priv->mac_addr, 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;
+
+	/* fill in supported rate */
+	left -= 2;
+	if (left < 0)
+		return 0;
+
+	*pos++ = WLAN_EID_SUPP_RATES;
+	*pos = 0;
+
+	/* exclude 60M rate */
+	active_rates = priv->rates_mask;
+	active_rates &= ~IWL_RATE_60M_MASK;
+
+	active_rate_basic = active_rates & IWL_BASIC_RATES_MASK;
+
+	cck_rates = IWL_CCK_RATES_MASK & active_rates;
+	ret_rates = iwl_supported_rate_to_ie(pos, cck_rates,
+					     active_rate_basic, &left);
+	active_rates &= ~ret_rates;
+
+	ret_rates = iwl_supported_rate_to_ie(pos, active_rates,
+					     active_rate_basic, &left);
+	active_rates &= ~ret_rates;
+
+	len += 2 + *pos;
+	pos += (*pos) + 1;
+
+	if (active_rates == 0)
+		goto fill_end;
+
+	/* fill in supported extended rate */
+	/* ...next IE... */
+	left -= 2;
+	if (left < 0)
+		return 0;
+	/* ... fill it in... */
+	*pos++ = WLAN_EID_EXT_SUPP_RATES;
+	*pos = 0;
+	iwl_supported_rate_to_ie(pos, active_rates, active_rate_basic, &left);
+	if (*pos > 0) {
+		len += 2 + *pos;
+		pos += (*pos) + 1;
+	} else {
+		pos--;
+	}
+
+ fill_end:
+
+	left -= 2;
+	if (left < 0)
+		return 0;
+
+	*pos++ = WLAN_EID_HT_CAPABILITY;
+	*pos = 0;
+	iwl_ht_cap_to_ie(sband, pos, &left);
+	if (*pos > 0)
+		len += 2 + *pos;
+
+	return (u16)len;
+}
+
+static u32 iwl_scan_tx_ant(struct iwl_priv *priv, enum ieee80211_band band)
+{
+	int i, ind;
+
+	ind = priv->scan_tx_ant[band];
+	for (i = 0; i < priv->hw_params.tx_chains_num; i++) {
+		ind = (ind+1) >= priv->hw_params.tx_chains_num ? 0 : ind+1;
+		if (priv->hw_params.valid_tx_ant & (1 << ind)) {
+			priv->scan_tx_ant[band] = ind;
+			break;
+		}
+	}
+	IWL_DEBUG_SCAN("select TX ANT = %c\n", 'A' + ind);
+	return scan_tx_ant[ind];
+}
+
+
+static void iwl_bg_request_scan(struct work_struct *data)
+{
+	struct iwl_priv *priv =
+	    container_of(data, struct iwl_priv, request_scan);
+	struct iwl_host_cmd cmd = {
+		.id = REPLY_SCAN_CMD,
+		.len = sizeof(struct iwl_scan_cmd),
+		.meta.flags = CMD_SIZE_HUGE,
+	};
+	struct iwl_scan_cmd *scan;
+	struct ieee80211_conf *conf = NULL;
+	int ret = 0;
+	u32 tx_ant;
+	u16 cmd_len;
+	enum ieee80211_band band;
+	u8 n_probes = 2;
+	u8 rx_chain = 0x7; /* bitmap: ABC chains */
+
+	conf = ieee80211_get_hw_conf(priv->hw);
+
+	mutex_lock(&priv->mutex);
+
+	if (!iwl_is_ready(priv)) {
+		IWL_WARNING("request scan called when driver not ready.\n");
+		goto done;
+	}
+
+	/* Make sure the scan wasn't cancelled before this queued work
+	 * was given the chance to run... */
+	if (!test_bit(STATUS_SCANNING, &priv->status))
+		goto done;
+
+	/* This should never be called or scheduled if there is currently
+	 * a scan active in the hardware. */
+	if (test_bit(STATUS_SCAN_HW, &priv->status)) {
+		IWL_DEBUG_INFO("Multiple concurrent scan requests in parallel. "
+			       "Ignoring second request.\n");
+		ret = -EIO;
+		goto done;
+	}
+
+	if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
+		IWL_DEBUG_SCAN("Aborting scan due to device shutdown\n");
+		goto done;
+	}
+
+	if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
+		IWL_DEBUG_HC("Scan request while abort pending.  Queuing.\n");
+		goto done;
+	}
+
+	if (iwl_is_rfkill(priv)) {
+		IWL_DEBUG_HC("Aborting scan due to RF Kill activation\n");
+		goto done;
+	}
+
+	if (!test_bit(STATUS_READY, &priv->status)) {
+		IWL_DEBUG_HC("Scan request while uninitialized.  Queuing.\n");
+		goto done;
+	}
+
+	if (!priv->scan_bands) {
+		IWL_DEBUG_HC("Aborting scan due to no requested bands\n");
+		goto done;
+	}
+
+	if (!priv->scan) {
+		priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
+				     IWL_MAX_SCAN_SIZE, GFP_KERNEL);
+		if (!priv->scan) {
+			ret = -ENOMEM;
+			goto done;
+		}
+	}
+	scan = priv->scan;
+	memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
+
+	scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
+	scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
+
+	if (iwl_is_associated(priv)) {
+		u16 interval = 0;
+		u32 extra;
+		u32 suspend_time = 100;
+		u32 scan_suspend_time = 100;
+		unsigned long flags;
+
+		IWL_DEBUG_INFO("Scanning while associated...\n");
+
+		spin_lock_irqsave(&priv->lock, flags);
+		interval = priv->beacon_int;
+		spin_unlock_irqrestore(&priv->lock, flags);
+
+		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("suspend_time 0x%X beacon interval %d\n",
+			       scan_suspend_time, interval);
+	}
+
+	/* We should add the ability for user to lock to PASSIVE ONLY */
+	if (priv->one_direct_scan) {
+		IWL_DEBUG_SCAN("Start direct scan for '%s'\n",
+				iwl_escape_essid(priv->direct_ssid,
+				priv->direct_ssid_len));
+		scan->direct_scan[0].id = WLAN_EID_SSID;
+		scan->direct_scan[0].len = priv->direct_ssid_len;
+		memcpy(scan->direct_scan[0].ssid,
+		       priv->direct_ssid, priv->direct_ssid_len);
+		n_probes++;
+	} else if (!iwl_is_associated(priv) && priv->essid_len) {
+		IWL_DEBUG_SCAN("Start direct scan for '%s' (not associated)\n",
+				iwl_escape_essid(priv->essid, priv->essid_len));
+		scan->direct_scan[0].id = WLAN_EID_SSID;
+		scan->direct_scan[0].len = priv->essid_len;
+		memcpy(scan->direct_scan[0].ssid, priv->essid, priv->essid_len);
+		n_probes++;
+	} else {
+		IWL_DEBUG_SCAN("Start indirect scan.\n");
+	}
+
+	scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
+	scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
+	scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
+
+
+	if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
+		band = IEEE80211_BAND_2GHZ;
+		scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
+		tx_ant = iwl_scan_tx_ant(priv, band);
+		if (priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_PURE_40_MSK)
+			scan->tx_cmd.rate_n_flags =
+				iwl_hw_set_rate_n_flags(IWL_RATE_6M_PLCP,
+							tx_ant);
+		else
+			scan->tx_cmd.rate_n_flags =
+				iwl_hw_set_rate_n_flags(IWL_RATE_1M_PLCP,
+							tx_ant |
+							RATE_MCS_CCK_MSK);
+		scan->good_CRC_th = 0;
+	} else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
+		band = IEEE80211_BAND_5GHZ;
+		tx_ant = iwl_scan_tx_ant(priv, band);
+		scan->tx_cmd.rate_n_flags =
+				iwl_hw_set_rate_n_flags(IWL_RATE_6M_PLCP,
+							tx_ant);
+		scan->good_CRC_th = IWL_GOOD_CRC_TH;
+
+		/* Force use of chains B and C (0x6) for scan Rx for 4965
+		 * Avoid A (0x1) because of its off-channel reception on A-band.
+		 * MIMO is not used here, but value is required */
+		if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
+			rx_chain = 0x6;
+	} else {
+		IWL_WARNING("Invalid scan band count\n");
+		goto done;
+	}
+
+	scan->rx_chain = RXON_RX_CHAIN_DRIVER_FORCE_MSK |
+				cpu_to_le16((0x7 << RXON_RX_CHAIN_VALID_POS) |
+				(rx_chain << RXON_RX_CHAIN_FORCE_SEL_POS) |
+				(0x7 << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS));
+
+	cmd_len = iwl_fill_probe_req(priv, band,
+				     (struct ieee80211_mgmt *)scan->data,
+				     IWL_MAX_SCAN_SIZE - sizeof(*scan));
+
+	scan->tx_cmd.len = cpu_to_le16(cmd_len);
+
+	if (priv->iw_mode == IEEE80211_IF_TYPE_MNTR)
+		scan->filter_flags = RXON_FILTER_PROMISC_MSK;
+
+	scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
+			       RXON_FILTER_BCON_AWARE_MSK);
+
+	scan->channel_count =
+		iwl_get_channels_for_scan(priv, band, 1, /* active */
+			n_probes,
+			(void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
+
+	if (scan->channel_count == 0) {
+		IWL_DEBUG_SCAN("channel count %d\n", scan->channel_count);
+		goto done;
+	}
+
+	cmd.len += le16_to_cpu(scan->tx_cmd.len) +
+	    scan->channel_count * sizeof(struct iwl_scan_channel);
+	cmd.data = scan;
+	scan->len = cpu_to_le16(cmd.len);
+
+	set_bit(STATUS_SCAN_HW, &priv->status);
+	ret = iwl_send_cmd_sync(priv, &cmd);
+	if (ret)
+		goto done;
+
+	queue_delayed_work(priv->workqueue, &priv->scan_check,
+			   IWL_SCAN_CHECK_WATCHDOG);
+
+	mutex_unlock(&priv->mutex);
+	return;
+
+ done:
+	/* inform mac80211 scan aborted */
+	queue_work(priv->workqueue, &priv->scan_completed);
+	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);
+
+	if (!iwl_is_ready(priv))
+		return;
+
+	mutex_lock(&priv->mutex);
+
+	set_bit(STATUS_SCAN_ABORTING, &priv->status);
+	iwl_send_scan_abort(priv);
+
+	mutex_unlock(&priv->mutex);
+}
+
+void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
+{
+	/*  FIXME: move here when resolved PENDING
+	 *  INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed); */
+	INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
+	INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
+	INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
+}
+EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
+