path: root/drivers/net/wireless/iwlwifi/iwl-scan.c

/******************************************************************************
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 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-io.h"
#include "iwl-helpers.h"
#include "iwl-agn.h"
#include "iwl-trans.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

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

	/* 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->shrd->status) ||
	    !test_bit(STATUS_GEO_CONFIGURED, &priv->shrd->status) ||
	    !test_bit(STATUS_SCAN_HW, &priv->shrd->status) ||
	    test_bit(STATUS_FW_ERROR, &priv->shrd->status) ||
	    test_bit(STATUS_EXIT_PENDING, &priv->shrd->status))
		return -EIO;

	ret = iwl_trans_send_cmd(trans(priv), &cmd);
	if (ret)
		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_SCAN(priv, "SCAN_ABORT ret %d.\n", pkt->u.status);
		ret = -EIO;
	}

	iwl_free_pages(priv->shrd, cmd.reply_page);
	return ret;
}

static void iwl_complete_scan(struct iwl_priv *priv, bool 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, aborted);
	}

	if (priv->scan_type == IWL_SCAN_ROC) {
		ieee80211_remain_on_channel_expired(priv->hw);
		priv->hw_roc_channel = NULL;
		schedule_delayed_work(&priv->hw_roc_disable_work, 10 * HZ);
	}

	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->shrd->mutex);

	if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->shrd->status))
		return;

	IWL_DEBUG_SCAN(priv, "Completed scan.\n");

	cancel_delayed_work(&priv->scan_check);

	aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->shrd->status);
	if (aborted)
		IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");

	if (!test_and_clear_bit(STATUS_SCANNING, &priv->shrd->status)) </