core/sap/src/sap_ch_select.c

/*
 * Copyright (c) 2012-2016 The Linux Foundation. All rights reserved.
 *
 * Previously licensed under the ISC license by Qualcomm Atheros, Inc.
 *
 *
 * Permission to use, copy, modify, and/or distribute this software for
 * any purpose with or without fee is hereby granted, provided that the
 * above copyright notice and this permission notice appear in all
 * copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * This file was originally distributed by Qualcomm Atheros, Inc.
 * under proprietary terms before Copyright ownership was assigned
 * to the Linux Foundation.
 */

/*===========================================================================

			s a p C h S e l e c t . C
   OVERVIEW:

   This software unit holds the implementation of the WLAN SAP modules
   functions for channel selection.

   DEPENDENCIES:

   Are listed for each API below.
   ===========================================================================*/

/*--------------------------------------------------------------------------
   Include Files
   ------------------------------------------------------------------------*/
#include "qdf_trace.h"
#include "csr_api.h"
#include "sme_api.h"
#include "sap_ch_select.h"
#include "sap_internal.h"
#ifdef ANI_OS_TYPE_QNX
#include "stdio.h"
#endif
#ifdef FEATURE_AP_MCC_CH_AVOIDANCE
#include "lim_utils.h"
#include "parser_api.h"
#endif /* FEATURE_AP_MCC_CH_AVOIDANCE */
#include "cds_utils.h"
#include "pld_common.h"

/*--------------------------------------------------------------------------
   Function definitions
   --------------------------------------------------------------------------*/

/*--------------------------------------------------------------------------
   Defines
   --------------------------------------------------------------------------*/
#define SAP_DEBUG

#define IS_RSSI_VALID(extRssi, rssi) \
	( \
		((extRssi < rssi) ? true : false) \
	)

#define SET_ACS_BAND(acs_band, pSapCtx) \
{ \
	if (pSapCtx->acs_cfg->start_ch <= 14 && \
		pSapCtx->acs_cfg->end_ch <= 14) \
		acs_band = eCSR_DOT11_MODE_11g; \
	else if (pSapCtx->acs_cfg->start_ch >= 14)\
		acs_band = eCSR_DOT11_MODE_11a; \
	else \
		acs_band = eCSR_DOT11_MODE_abg; \
}

#ifdef FEATURE_WLAN_CH_AVOID
sapSafeChannelType safe_channels[NUM_CHANNELS] = {
	{1, true},
	{2, true},
	{3, true},
	{4, true},
	{5, true},
	{6, true},
	{7, true},
	{8, true},
	{9, true},
	{10, true},
	{11, true},
	{12, true},
	{13, true},
	{14, true},
	{36, true},
	{40, true},
	{44, true},
	{48, true},
	{52, true},
	{56, true},
	{60, true},
	{64, true},
	{100, true},
	{104, true},
	{108, true},
	{112, true},
	{116, true},
	{120, true},
	{124, true},
	{128, true},
	{132, true},
	{136, true},
	{140, true},
	{144, true},
	{149, true},
	{153, true},
	{157, true},
	{161, true},
	{165, true},
};
#endif

typedef struct {
	uint16_t chStartNum;
	uint32_t weight;
} sapAcsChannelInfo;

sapAcsChannelInfo acs_ht40_channels5_g[] = {
	{36, SAP_ACS_WEIGHT_MAX},
	{44, SAP_ACS_WEIGHT_MAX},
	{52, SAP_ACS_WEIGHT_MAX},
	{60, SAP_ACS_WEIGHT_MAX},
	{100, SAP_ACS_WEIGHT_MAX},
	{108, SAP_ACS_WEIGHT_MAX},
	{116, SAP_ACS_WEIGHT_MAX},
	{124, SAP_ACS_WEIGHT_MAX},
	{132, SAP_ACS_WEIGHT_MAX},
	{140, SAP_ACS_WEIGHT_MAX},
	{149, SAP_ACS_WEIGHT_MAX},
	{157, SAP_ACS_WEIGHT_MAX},
};

sapAcsChannelInfo acs_ht80_channels[] = {
	{36, SAP_ACS_WEIGHT_MAX},
	{52, SAP_ACS_WEIGHT_MAX},
	{100, SAP_ACS_WEIGHT_MAX},
	{116, SAP_ACS_WEIGHT_MAX},
	{132, SAP_ACS_WEIGHT_MAX},
	{149, SAP_ACS_WEIGHT_MAX},
};

sapAcsChannelInfo acs_vht160_channels[] = {
	{36, SAP_ACS_WEIGHT_MAX},
	{100, SAP_ACS_WEIGHT_MAX},
};

sapAcsChannelInfo acs_ht40_channels24_g[] = {
	{1, SAP_ACS_WEIGHT_MAX},
	{2, SAP_ACS_WEIGHT_MAX},
	{3, SAP_ACS_WEIGHT_MAX},
	{4, SAP_ACS_WEIGHT_MAX},
	{9, SAP_ACS_WEIGHT_MAX},
};

#define CHANNEL_165  165

/* rssi discount for channels in PCL */
#define PCL_RSSI_DISCOUNT 10

#ifdef FEATURE_AP_MCC_CH_AVOIDANCE
/**
 * sap_check_n_add_channel() - checks and add given channel in sap context's
 * avoid_channels_info struct
 * @sap_ctx:           sap context.
 * @new_channel:       channel to be added to sap_ctx's avoid ch info
 *
 * sap_ctx contains sap_avoid_ch_info strcut containing the list of channels on
 * which MDM device's AP with MCC was detected. This function will add channels
 * to that list after checking for duplicates.
 *
 * Return: true: if channel was added or already present
 *   else false: if channel list was already full.
 */
bool
sap_check_n_add_channel(ptSapContext sap_ctx,
			uint8_t new_channel)
{
	uint8_t i = 0;
	struct sap_avoid_channels_info *ie_info =
		&sap_ctx->sap_detected_avoid_ch_ie;

	for (i = 0; i < sizeof(ie_info->channels); i++) {
		if (ie_info->channels[i] == new_channel)
			break;

		if (ie_info->channels[i] == 0) {
			ie_info->channels[i] = new_channel;
			break;
		}
	}
	if (i == sizeof(ie_info->channels))
		return false;
	else
		return true;
}
/**
 * sap_check_n_add_overlapped_chnls() - checks & add overlapped channels
 *                                      to primary channel in 2.4Ghz band.
 * @sap_ctx:           sap context.
 * @primary_chnl:      primary channel to be avoided.
 *
 * sap_ctx contains sap_avoid_ch_info struct containing the list of channels on
 * which MDM device's AP with MCC was detected. This function will add channels
 * to that list after checking for duplicates.
 *
 * Return: true: if channel was added or already present
 *   else false: if channel list was already full.
 */
static bool
sap_check_n_add_overlapped_chnls(ptSapContext sap_ctx, uint8_t primary_channel)
{
	uint8_t i = 0, j = 0, upper_chnl = 0, lower_chnl = 0;
	struct sap_avoid_channels_info *ie_info =
		&sap_ctx->sap_detected_avoid_ch_ie;
	/*
	 * if primary channel less than channel 1 or out of 2g band then
	 * no further process is required. return true in this case.
	 */
	if (primary_channel < CHANNEL_1 || primary_channel > CHANNEL_14)
		return true;

	/* lower channel is one channel right before primary channel */
	lower_chnl = primary_channel - 1;
	/* upper channel is one channel right after primary channel */
	upper_chnl = primary_channel + 1;

	/* lower channel needs to be non-zero, zero is not valid channel */
	if (lower_chnl > (CHANNEL_1 - 1)) {
		for (i = 0; i < sizeof(ie_info->channels); i++) {
			if (ie_info->channels[i] == lower_chnl)
				break;
			if (ie_info->channels[i] == 0) {
				ie_info->channels[i] = lower_chnl;
				break;
			}
		}
	}
	/* upper channel needs to be atleast last channel in 2.4Ghz band */
	if (upper_chnl < (CHANNEL_14 + 1)) {
		for (j = 0; j < sizeof(ie_info->channels); j++) {
			if (ie_info->channels[j] == upper_chnl)
				break;
			if (ie_info->channels[j] == 0) {
				ie_info->channels[j] = upper_chnl;
				break;
			}
		}
	}
	if (i == sizeof(ie_info->channels) || j == sizeof(ie_info->channels))
		return false;
	else
		return true;
}

/**
 * sap_process_avoid_ie() - processes the detected Q2Q IE
 * context's avoid_channels_info struct
 * @hal:                hal handle
 * @sap_ctx:            sap context.
 * @scan_result:        scan results for ACS scan.
 * @spect_info:         spectrum weights array to update
 *
 * Detection of Q2Q IE indicates presence of another MDM device with its AP
 * operating in MCC mode. This function parses the scan results and processes
 * the Q2Q IE if found. It then extracts the channels and populates them in
 * sap_ctx struct. It also increases the weights of those channels so that
 * ACS logic will avoid those channels in its selection algorithm.
 *
 * Return: void
 */
void sap_process_avoid_ie(tHalHandle hal,
			  ptSapContext sap_ctx,
			  tScanResultHandle scan_result,
			  tSapChSelSpectInfo *spect_info)
{
	uint32_t total_ie_len = 0;
	uint8_t *temp_ptr = NULL;
	uint8_t i = 0;
	struct sAvoidChannelIE *avoid_ch_ie;
	tCsrScanResultInfo *node = NULL;
	tpAniSirGlobal mac_ctx = NULL;
	tSapSpectChInfo *spect_ch = NULL;

	mac_ctx = PMAC_STRUCT(hal);
	spect_ch = spect_info->pSpectCh;
	node = sme_scan_result_get_first(hal, scan_result);

	while (node) {
		total_ie_len = (node->BssDescriptor.length +
			sizeof(uint16_t) + sizeof(uint32_t) -
			sizeof(tSirBssDescription));
		temp_ptr = cfg_get_vendor_ie_ptr_from_oui(mac_ctx,
				SIR_MAC_QCOM_VENDOR_OUI,
				SIR_MAC_QCOM_VENDOR_SIZE,
				((uint8_t *)&node->BssDescriptor.ieFields),
				total_ie_len);

		if (temp_ptr) {
			avoid_ch_ie = (struct sAvoidChannelIE *)temp_ptr;
			if (avoid_ch_ie->type != QCOM_VENDOR_IE_MCC_AVOID_CH)
				continue;

			sap_ctx->sap_detected_avoid_ch_ie.present = 1;
			QDF_TRACE(QDF_MODULE_ID_SAP,
				  QDF_TRACE_LEVEL_DEBUG,
				  "Q2Q IE - avoid ch %d",
				  avoid_ch_ie->channel);
			/* add this channel to to_avoid channel list */
			sap_check_n_add_channel(sap_ctx,
					avoid_ch_ie->channel);
			sap_check_n_add_overlapped_chnls(sap_ctx,
					avoid_ch_ie->channel);
			/*
			 * Mark weight of these channel present in IE to MAX
			 * so that ACS logic will to avoid thse channels
			 */
			for (i = 0; i < spect_info->numSpectChans; i++)
				if (spect_ch[i].chNum == avoid_ch_ie->channel) {
					/*
					 * weight is set more than max so that,
					 * in the case of other channels being
					 * assigned max weight due to noise,
					 * they may be preferred over channels
					 * with Q2Q IE.
					 */
					spect_ch[i].weight = SAP_ACS_WEIGHT_MAX + 1;
					spect_ch[i].weight_copy =
						SAP_ACS_WEIGHT_MAX + 1;
					break;
				}
		} /* if (temp_ptr) */
		node = sme_scan_result_get_next(hal, scan_result);
	}
}
#endif /* FEATURE_AP_MCC_CH_AVOIDANCE */

#ifdef FEATURE_WLAN_CH_AVOID
/*==========================================================================
   FUNCTION    sap_update_unsafe_channel_list

   DESCRIPTION
    Function  Undate unsafe channel list table

   DEPENDENCIES
    NA.

   IN
    SapContext pointer

   RETURN VALUE
    NULL
   ============================================================================*/
void sap_update_unsafe_channel_list(ptSapContext pSapCtx)
{
	uint16_t i, j;
	uint16_t unsafe_channel_list[NUM_CHANNELS];
	uint16_t unsafe_channel_count = 0;
	qdf_device_t qdf_ctx = cds_get_context(QDF_MODULE_ID_QDF_DEVICE);

	if (!qdf_ctx) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_FATAL,
			  "qdf_ctx is NULL");
		return;
	}

	/* Flush, default set all channel safe */
	for (i = 0; i < NUM_CHANNELS; i++) {
		safe_channels[i].isSafe = true;
	}

	/* Try to find unsafe channel */
#if defined(FEATURE_WLAN_STA_AP_MODE_DFS_DISABLE)
	for (i = 0; i < NUM_CHANNELS; i++) {
		if (pSapCtx->dfs_ch_disable == true) {
			if (CDS_IS_DFS_CH(safe_channels[i].channelNumber)) {
				safe_channels[i].isSafe = false;
				QDF_TRACE(QDF_MODULE_ID_SAP,
					QDF_TRACE_LEVEL_INFO_HIGH,
					"%s: DFS Ch %d is not safe in"
					" Concurrent mode",
					__func__,
					safe_channels[i].channelNumber);
			}
		}
	}
#endif
	pld_get_wlan_unsafe_channel(qdf_ctx->dev,
				    unsafe_channel_list,
				     &unsafe_channel_count,
				     sizeof(unsafe_channel_list));

	for (i = 0; i < unsafe_channel_count; i++) {
		for (j = 0; j < NUM_CHANNELS; j++) {
			if (safe_channels[j].channelNumber ==
			    unsafe_channel_list[i]) {
				/* Found unsafe channel, update it */
				safe_channels[j].isSafe = false;
				QDF_TRACE(QDF_MODULE_ID_SAP,
					  QDF_TRACE_LEVEL_ERROR,
					  FL("CH %d is not safe"),
					  unsafe_channel_list[i]);
				break;
			}
		}
	}

	return;
}

#endif /* FEATURE_WLAN_CH_AVOID */

/*==========================================================================
   FUNCTION    sap_cleanup_channel_list

   DESCRIPTION
    Function sap_cleanup_channel_list frees up the memory allocated to the channel list.

   DEPENDENCIES
    NA.

   PARAMETERS

    IN
    NULL

   RETURN VALUE
    NULL
   ============================================================================*/

void sap_cleanup_channel_list(void *p_cds_gctx)
{
	ptSapContext pSapCtx;

	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO,
		  "Cleaning up the channel list structure");

	if (NULL == p_cds_gctx) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_FATAL,
			  "SAP Global Context is NULL");
		return;
	}

	pSapCtx = CDS_GET_SAP_CB(p_cds_gctx);
	if (NULL == pSapCtx) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_FATAL,
			  "SAP Context is NULL");
		return;
	}

	pSapCtx->SapChnlList.numChannel = 0;
	if (pSapCtx->SapChnlList.channelList) {
		qdf_mem_free(pSapCtx->SapChnlList.channelList);
		pSapCtx->SapChnlList.channelList = NULL;
	}

	pSapCtx->SapAllChnlList.numChannel = 0;
	if (pSapCtx->SapAllChnlList.channelList) {
		qdf_mem_free(pSapCtx->SapAllChnlList.channelList);
		pSapCtx->SapAllChnlList.channelList = NULL;
	}
}

/**
 * sap_select_preferred_channel_from_channel_list() - to calc best cahnnel
 * @best_chnl: best channel already calculated among all the chanels
 * @sap_ctx: sap context
 * @spectinfo_param: Pointer to tSapChSelSpectInfo structure
 *
 * This function calculates the best channel among the configured channel list.
 * If channel list not configured then returns the best channel calculated
 * among all the channel list.
 *
 * Return: uint8_t best channel
 */
static
uint8_t sap_select_preferred_channel_from_channel_list(uint8_t best_chnl,
				ptSapContext sap_ctx,
				tSapChSelSpectInfo *spectinfo_param)
{
	uint8_t i = 0;

	/*
	 * If Channel List is not Configured don't do anything
	 * Else return the Best Channel from the Channel List
	 */
	if ((NULL == sap_ctx->acs_cfg->ch_list) ||
		(NULL == spectinfo_param) ||
		(0 == sap_ctx->acs_cfg->ch_list_count))
		return best_chnl;

	if (best_chnl <= 0 || best_chnl > 252)
		return SAP_CHANNEL_NOT_SELECTED;

	/* Select the best channel from allowed list */
	for (i = 0; i < sap_ctx->acs_cfg->ch_list_count; i++) {
		if (sap_ctx->acs_cfg->ch_list[i] == best_chnl) {
			QDF_TRACE(QDF_MODULE_ID_SAP,
				QDF_TRACE_LEVEL_INFO_HIGH,
				"Best channel is: %d",
				best_chnl);
			return best_chnl;
		}
	}

	return SAP_CHANNEL_NOT_SELECTED;
}

/*==========================================================================
   FUNCTION    sap_chan_sel_init

   DESCRIPTION
    Function sap_chan_sel_init allocates the memory, intializes the
    structures used by the channel selection algorithm

   DEPENDENCIES
    NA.

   PARAMETERS

    IN
    halHandle          : Pointer to tHalHandle
   *pSpectInfoParams  : Pointer to tSapChSelSpectInfo structure
     pSapCtx           : Pointer to SAP Context

   RETURN VALUE
    bool:  Success or FAIL

   SIDE EFFECTS
   ============================================================================*/
static bool sap_chan_sel_init(tHalHandle halHandle,
			      tSapChSelSpectInfo *pSpectInfoParams,
			      ptSapContext pSapCtx)
{
	tSapSpectChInfo *pSpectCh = NULL;
	uint8_t *pChans = NULL;
	uint16_t channelnum = 0;
	tpAniSirGlobal pMac = PMAC_STRUCT(halHandle);
	bool chSafe = true;
#ifdef FEATURE_WLAN_CH_AVOID
	uint16_t i;
#endif
	uint32_t dfs_master_cap_enabled;
	bool include_dfs_ch = true;

	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH, "In %s",
		  __func__);

	pSpectInfoParams->numSpectChans =
		pMac->scan.base_channels.numChannels;

	/* Allocate memory for weight computation of 2.4GHz */
	pSpectCh =
		(tSapSpectChInfo *) qdf_mem_malloc((pSpectInfoParams->numSpectChans)
						   * sizeof(*pSpectCh));

	if (pSpectCh == NULL) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_ERROR,
			  "In %s, QDF_MALLOC_ERR", __func__);
		return eSAP_FALSE;
	}

	qdf_mem_zero(pSpectCh,
		     (pSpectInfoParams->numSpectChans) * sizeof(*pSpectCh));

	/* Initialize the pointers in the DfsParams to the allocated memory */
	pSpectInfoParams->pSpectCh = pSpectCh;

	pChans = pMac->scan.base_channels.channelList;

#if defined(FEATURE_WLAN_STA_AP_MODE_DFS_DISABLE)
	if (pSapCtx->dfs_ch_disable == true)
		include_dfs_ch = false;
#endif
	sme_cfg_get_int(halHandle, WNI_CFG_DFS_MASTER_ENABLED,
			&dfs_master_cap_enabled);
	if (dfs_master_cap_enabled == 0 ||
	    ACS_DFS_MODE_DISABLE == pSapCtx->dfs_mode)
		include_dfs_ch = false;

	/* Fill the channel number in the spectrum in the operating freq band */
	for (channelnum = 0;
	     channelnum < pSpectInfoParams->numSpectChans;
	     channelnum++, pChans++, pSpectCh++) {
		chSafe = true;

		/* check if the channel is in NOL blacklist */
		if (sap_dfs_is_channel_in_nol_list(pSapCtx, *pChans,
						   PHY_SINGLE_CHANNEL_CENTERED)) {
			QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
				  "In %s, Ch %d is in NOL list", __func__,
				  *pChans);
			chSafe = false;
			continue;
		}

		if (include_dfs_ch == false) {
			if (CDS_IS_DFS_CH(*pChans)) {
				chSafe = false;
				QDF_TRACE(QDF_MODULE_ID_SAP,
					  QDF_TRACE_LEVEL_INFO_HIGH,
					  "In %s, DFS Ch %d not considered for ACS",
					  __func__, *pChans);
				continue;
			}
		}

#ifdef FEATURE_WLAN_CH_AVOID
		for (i = 0; i < NUM_CHANNELS; i++) {
			if ((safe_channels[i].channelNumber == *pChans) &&
			    (false == safe_channels[i].isSafe)) {
				QDF_TRACE(QDF_MODULE_ID_SAP,
					  QDF_TRACE_LEVEL_INFO_HIGH,
					  "In %s, Ch %d is not safe", __func__,
					  *pChans);
				chSafe = false;
				break;
			}
		}
#endif /* FEATURE_WLAN_CH_AVOID */

		/* OFDM rates are not supported on channel 14 */
		if (*pChans == 14 &&
		    eCSR_DOT11_MODE_11b != pSapCtx->csr_roamProfile.phyMode) {
			continue;
		}

		/* Skip DSRC channels */
		if (cds_is_dsrc_channel(cds_chan_to_freq(*pChans)))
			continue;

		if (true == chSafe) {
			pSpectCh->chNum = *pChans;
			pSpectCh->valid = eSAP_TRUE;
			pSpectCh->rssiAgr = SOFTAP_MIN_RSSI;    /* Initialise for all channels */
			pSpectCh->channelWidth = SOFTAP_HT20_CHANNELWIDTH;      /* Initialise 20MHz for all the Channels */
		}
	}
	return eSAP_TRUE;
}

/*==========================================================================
   FUNCTION    sapweight_rssi_count

   DESCRIPTION
    Function weightRssiCount calculates the channel weight due to rssi
    and data count(here number of BSS observed)

   DEPENDENCIES
    NA.

   PARAMETERS

    IN
    rssi        : Max signal strength receieved from a BSS for the channel
    count       : Number of BSS observed in the channel

   RETURN VALUE
    uint32_t     : Calculated channel weight based on above two

   SIDE EFFECTS
   ============================================================================*/
static uint32_t sapweight_rssi_count(int8_t rssi, uint16_t count)
{
	int32_t rssiWeight = 0;
	int32_t countWeight = 0;
	uint32_t rssicountWeight = 0;

	/* Weight from RSSI */
	rssiWeight = SOFTAP_RSSI_WEIGHT * (rssi - SOFTAP_MIN_RSSI)
		     / (SOFTAP_MAX_RSSI - SOFTAP_MIN_RSSI);

	if (rssiWeight > SOFTAP_RSSI_WEIGHT)
		rssiWeight = SOFTAP_RSSI_WEIGHT;
	else if (rssiWeight < 0)
		rssiWeight = 0;

	/* Weight from data count */
	countWeight = SOFTAP_COUNT_WEIGHT * (count - SOFTAP_MIN_COUNT)
		      / (SOFTAP_MAX_COUNT - SOFTAP_MIN_COUNT);

	if (countWeight > SOFTAP_COUNT_WEIGHT)
		countWeight = SOFTAP_COUNT_WEIGHT;

	rssicountWeight = rssiWeight + countWeight;

	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
		  "In %s, rssiWeight=%d, countWeight=%d, rssicountWeight=%d",
		  __func__, rssiWeight, countWeight, rssicountWeight);

	return rssicountWeight;
}

/**
 * sap_update_rssi_bsscount() - updates bss count and rssi effect.
 *
 * @pSpectCh:     Channel Information
 * @offset:       Channel Offset
 * @sap_24g:      Channel is in 2.4G or 5G
 *
 * sap_update_rssi_bsscount updates bss count and rssi effect based
 * on the channel offset.
 *
 * Return: None.
 */

static void sap_update_rssi_bsscount(tSapSpectChInfo *pSpectCh, int32_t offset,
				     bool sap_24g)
{
	tSapSpectChInfo *pExtSpectCh = NULL;
	int32_t rssi, rsssi_effect;

	pExtSpectCh = (pSpectCh + offset);
	if (pExtSpectCh != NULL) {
		++pExtSpectCh->bssCount;
		switch (offset) {
		case -1:
		case 1:
			rsssi_effect = sap_24g ?
			    SAP_24GHZ_FIRST_OVERLAP_CHAN_RSSI_EFFECT_PRIMARY :
			    SAP_SUBBAND1_RSSI_EFFECT_PRIMARY;
			break;
		case -2:
		case 2:
			rsssi_effect = sap_24g ?
			    SAP_24GHZ_SEC_OVERLAP_CHAN_RSSI_EFFECT_PRIMARY :
			    SAP_SUBBAND2_RSSI_EFFECT_PRIMARY;
			break;
		case -3:
		case 3:
			rsssi_effect = sap_24g ?
			    SAP_24GHZ_THIRD_OVERLAP_CHAN_RSSI_EFFECT_PRIMARY :
			    SAP_SUBBAND3_RSSI_EFFECT_PRIMARY;
			break;
		case -4:
		case 4:
			rsssi_effect = sap_24g ?
			    SAP_24GHZ_FOURTH_OVERLAP_CHAN_RSSI_EFFECT_PRIMARY :
			    SAP_SUBBAND4_RSSI_EFFECT_PRIMARY;
			break;
		case -5:
		case 5:
			rsssi_effect = SAP_SUBBAND5_RSSI_EFFECT_PRIMARY;
			break;
		case -6:
		case 6:
			rsssi_effect = SAP_SUBBAND6_RSSI_EFFECT_PRIMARY;
			break;
		case -7:
		case 7:
			rsssi_effect = SAP_SUBBAND7_RSSI_EFFECT_PRIMARY;
			break;
		default:
			rsssi_effect = 0;
			break;
		}

		rssi = pSpectCh->rssiAgr + rsssi_effect;
		if (IS_RSSI_VALID(pExtSpectCh->rssiAgr, rssi))
			pExtSpectCh->rssiAgr = rssi;
		if (pExtSpectCh->rssiAgr < SOFTAP_MIN_RSSI)
			pExtSpectCh->rssiAgr = SOFTAP_MIN_RSSI;
	}
}

/**
 * sap_upd_chan_spec_params() - sap_upd_chan_spec_params
 *                              updates channel parameters obtained from Beacon
 * @pBeaconStruct Beacon strucutre populated by parse_beacon function
 * @channelWidth Channel width
 * @secondaryChannelOffset Secondary Channel Offset
 * @vhtSupport If channel supports VHT
 * @centerFreq Central frequency for the given channel.
 *
 * sap_upd_chan_spec_params updates the spectrum channels based on the
 * pBeaconStruct obtained from Beacon IE
 *
 * Return: NA.
 */

static void sap_upd_chan_spec_params(tSirProbeRespBeacon *pBeaconStruct,
				     uint16_t *channelWidth,
				     uint16_t *secondaryChannelOffset,
				     uint16_t *vhtSupport,
				     uint16_t *centerFreq,
				     uint16_t *centerFreq_2)
{
	if (NULL == pBeaconStruct) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_ERROR,
			  FL("pBeaconStruct is NULL"));
		return;
	}

	if (pBeaconStruct->HTCaps.present && pBeaconStruct->HTInfo.present) {
		*channelWidth = pBeaconStruct->HTCaps.supportedChannelWidthSet;
		*secondaryChannelOffset =
			pBeaconStruct->HTInfo.secondaryChannelOffset;
		if (!pBeaconStruct->VHTOperation.present)
			return;
		*vhtSupport = pBeaconStruct->VHTOperation.present;
		if (pBeaconStruct->VHTOperation.chanWidth) {
			*centerFreq =
				pBeaconStruct->VHTOperation.chanCenterFreqSeg1;
			*centerFreq_2 =
				pBeaconStruct->VHTOperation.chanCenterFreqSeg2;
			 /*
			  * LHS follows tSirMacHTChannelWidth, while RHS follows
			  * WNI_CFG_VHT_CHANNEL_WIDTH_X format hence following
			  * adjustment
			  */
			*channelWidth =
				pBeaconStruct->VHTOperation.chanWidth + 1;

		}
	}
}

/**
 * sap_update_rssi_bsscount_vht_5G() - updates bss count and rssi effect.
 *
 * @spect_ch:     Channel Information
 * @offset:       Channel Offset
 * @num_ch:       no.of channels
 *
 * sap_update_rssi_bsscount_vht_5G updates bss count and rssi effect based
 * on the channel offset.
 *
 * Return: None.
 */

static void sap_update_rssi_bsscount_vht_5G(tSapSpectChInfo *spect_ch,
					    int32_t offset,
					    uint16_t num_ch)
{
	int32_t ch_offset;
	uint16_t i, cnt;

	if (!offset)
		return;
	if (offset > 0)
		cnt = num_ch;
	else
		cnt = num_ch + 1;
	for (i = 0; i < cnt; i++) {
		ch_offset = offset + i;
		if (ch_offset == 0)
			continue;
		sap_update_rssi_bsscount(spect_ch, ch_offset, false);
	}
}
/**
 * sap_interference_rssi_count_5G() - sap_interference_rssi_count
 *                                    considers the Adjacent channel rssi and
 *                                    data count(here number of BSS observed)
 * @spect_ch:        Channel Information
 * @chan_width:      Channel width parsed from beacon IE
 * @sec_chan_offset: Secondary Channel Offset
 * @center_freq:     Central frequency for the given channel.
 * @channel_id:      channel_id
 *
 * sap_interference_rssi_count_5G considers the Adjacent channel rssi
 * and data count(here number of BSS observed)
 *
 * Return: NA.
 */

static void sap_interference_rssi_count_5G(tSapSpectChInfo *spect_ch,
					   uint16_t chan_width,
					   uint16_t sec_chan_offset,
					   uint16_t center_freq,
					   uint16_t center_freq_2,
					   uint8_t channel_id)
{
	uint16_t num_ch;
	int32_t offset = 0;
	if (NULL == spect_ch) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_ERROR,
			  FL("spect_ch is NULL"));
		return;
	}

	/* Updating the received ChannelWidth */
	if (spect_ch->channelWidth != chan_width)
		spect_ch->channelWidth = chan_width;
	/* If received ChannelWidth is other than HT20,
	 * we need to update the extension channel Params as well
	 * chan_width == 0, HT20
	 * chan_width == 1, HT40
	 * chan_width == 2, VHT80
	 * chan_width == 3, VHT160
	 */

	switch (spect_ch->channelWidth) {
	case eHT_CHANNEL_WIDTH_40MHZ:   /* HT40 */
		switch (sec_chan_offset) {
		/* Above the Primary Channel */
		case PHY_DOUBLE_CHANNEL_LOW_PRIMARY:
			sap_update_rssi_bsscount(spect_ch, 1, false);
			return;

		/* Below the Primary channel */
		case PHY_DOUBLE_CHANNEL_HIGH_PRIMARY:
			sap_update_rssi_bsscount(spect_ch, -1, false);
			return;
		}
		return;
	case eHT_CHANNEL_WIDTH_80MHZ:   /* VHT80 */
		num_ch = 3;
		if ((center_freq - channel_id) == 6) {
			offset = 1;
		} else if ((center_freq - channel_id) == 2) {
			offset = -1;
		} else if ((center_freq - channel_id) == -2) {
			offset = -2;
		} else if ((center_freq - channel_id) == -6) {
			offset = -3;
		}
		break;
	case eHT_CHANNEL_WIDTH_160MHZ:   /* VHT160 */
		num_ch = 7;
		if ((center_freq - channel_id) == 14)
			offset = 1;
		else if ((center_freq - channel_id) == 10)
			offset = -1;
		else if ((center_freq - channel_id) == 6)
			offset = -2;
		else if ((center_freq - channel_id) == 2)
			offset = -3;
		else if ((center_freq - channel_id) == -2)
			offset = -4;
		else if ((center_freq - channel_id) == -6)
			offset = -5;
		else if ((center_freq - channel_id) == -10)
			offset = -6;
		else if ((center_freq - channel_id) == -14)
			offset = -7;
		break;
	default:
		return;
	}
	sap_update_rssi_bsscount_vht_5G(spect_ch, offset, num_ch);
}

/**
 * sap_interference_rssi_count() - sap_interference_rssi_count
 *                                 considers the Adjacent channel rssi
 *                                 and data count(here number of BSS observed)
 * @spect_ch    Channel Information
 *
 * sap_interference_rssi_count considers the Adjacent channel rssi
 * and data count(here number of BSS observed)
 *
 * Return: None.
 */

static void sap_interference_rssi_count(tSapSpectChInfo *spect_ch)
{
	if (NULL == spect_ch) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_ERROR,
			  "%s: spect_ch is NULL", __func__);
		return;
	}

	switch (spect_ch->chNum) {
	case CHANNEL_1:
		sap_update_rssi_bsscount(spect_ch, 1, true);
		sap_update_rssi_bsscount(spect_ch, 2, true);
		sap_update_rssi_bsscount(spect_ch, 3, true);
		sap_update_rssi_bsscount(spect_ch, 4, true);
		break;

	case CHANNEL_2:
		sap_update_rssi_bsscount(spect_ch, -1, true);
		sap_update_rssi_bsscount(spect_ch, 1, true);
		sap_update_rssi_bsscount(spect_ch, 2, true);
		sap_update_rssi_bsscount(spect_ch, 3, true);
		sap_update_rssi_bsscount(spect_ch, 4, true);
		break;
	case CHANNEL_3:
		sap_update_rssi_bsscount(spect_ch, -2, true);
		sap_update_rssi_bsscount(spect_ch, -1, true);
		sap_update_rssi_bsscount(spect_ch, 1, true);
		sap_update_rssi_bsscount(spect_ch, 2, true);
		sap_update_rssi_bsscount(spect_ch, 3, true);
		sap_update_rssi_bsscount(spect_ch, 4, true);
		break;
	case CHANNEL_4:
		sap_update_rssi_bsscount(spect_ch, -3, true);
		sap_update_rssi_bsscount(spect_ch, -2, true);
		sap_update_rssi_bsscount(spect_ch, -1, true);
		sap_update_rssi_bsscount(spect_ch, 1, true);
		sap_update_rssi_bsscount(spect_ch, 2, true);
		sap_update_rssi_bsscount(spect_ch, 3, true);
		sap_update_rssi_bsscount(spect_ch, 4, true);
		break;

	case CHANNEL_5:
	case CHANNEL_6:
	case CHANNEL_7:
	case CHANNEL_8:
	case CHANNEL_9:
	case CHANNEL_10:
		sap_update_rssi_bsscount(spect_ch, -4, true);
		sap_update_rssi_bsscount(spect_ch, -3, true);
		sap_update_rssi_bsscount(spect_ch, -2, true);
		sap_update_rssi_bsscount(spect_ch, -1, true);
		sap_update_rssi_bsscount(spect_ch, 1, true);
		sap_update_rssi_bsscount(spect_ch, 2, true);
		sap_update_rssi_bsscount(spect_ch, 3, true);
		sap_update_rssi_bsscount(spect_ch, 4, true);
		break;

	case CHANNEL_11:
		sap_update_rssi_bsscount(spect_ch, -4, true);
		sap_update_rssi_bsscount(spect_ch, -3, true);
		sap_update_rssi_bsscount(spect_ch, -2, true);
		sap_update_rssi_bsscount(spect_ch, -1, true);
		sap_update_rssi_bsscount(spect_ch, 1, true);
		sap_update_rssi_bsscount(spect_ch, 2, true);
		sap_update_rssi_bsscount(spect_ch, 3, true);
		break;

	case CHANNEL_12:
		sap_update_rssi_bsscount(spect_ch, -4, true);
		sap_update_rssi_bsscount(spect_ch, -3, true);
		sap_update_rssi_bsscount(spect_ch, -2, true);
		sap_update_rssi_bsscount(spect_ch, -1, true);
		sap_update_rssi_bsscount(spect_ch, 1, true);
		sap_update_rssi_bsscount(spect_ch, 2, true);
		break;

	case CHANNEL_13:
		sap_update_rssi_bsscount(spect_ch, -4, true);
		sap_update_rssi_bsscount(spect_ch, -3, true);
		sap_update_rssi_bsscount(spect_ch, -2, true);
		sap_update_rssi_bsscount(spect_ch, -1, true);
		sap_update_rssi_bsscount(spect_ch, 1, true);
		break;

	case CHANNEL_14:
		sap_update_rssi_bsscount(spect_ch, -4, true);
		sap_update_rssi_bsscount(spect_ch, -3, true);
		sap_update_rssi_bsscount(spect_ch, -2, true);
		sap_update_rssi_bsscount(spect_ch, -1, true);
		break;

	default:
		break;
	}
}

/**
 * ch_in_pcl() - Is channel in the Preferred Channel List (PCL)
 * @sap_ctx: SAP context which contains the current PCL
 * @channel: Input channel number to be checked
 *
 * Check if a channel is in the preferred channel list
 *
 * Return:
 *   true:    channel is in PCL,
 *   false:   channel is not in PCL
 */
static bool ch_in_pcl(ptSapContext sap_ctx, uint8_t channel)
{
	uint32_t i;

	for (i = 0; i < sap_ctx->acs_cfg->pcl_ch_count; i++) {
		if (channel == sap_ctx->acs_cfg->pcl_channels[i])
			return true;
	}

	return false;
}

/**
 * sap_compute_spect_weight() - Compute spectrum weight
 * @pSpectInfoParams: Pointer to the tSpectInfoParams structure
 * @halHandle: Pointer to HAL handle
 * @pResult: Pointer to tScanResultHandle
 * @sap_ctx: Context of the SAP
 *
 * Main function for computing the weight of each channel in the
 * spectrum based on the RSSI value of the BSSes on the channel
 * and number of BSS
 */
static void sap_compute_spect_weight(tSapChSelSpectInfo *pSpectInfoParams,
				     tHalHandle halHandle,
				     tScanResultHandle pResult,
				     ptSapContext sap_ctx)
{
	int8_t rssi = 0;
	uint8_t chn_num = 0;
	uint8_t channel_id = 0;

	tCsrScanResultInfo *pScanResult;
	tSapSpectChInfo *pSpectCh = pSpectInfoParams->pSpectCh;
	uint32_t operatingBand;
	uint16_t channelWidth;
	uint16_t secondaryChannelOffset;
	uint16_t centerFreq;
	uint16_t centerFreq_2 = 0;
	uint16_t vhtSupport;
	uint32_t ieLen = 0;
	tSirProbeRespBeacon *pBeaconStruct;
	tpAniSirGlobal pMac = (tpAniSirGlobal) halHandle;

	pBeaconStruct = qdf_mem_malloc(sizeof(tSirProbeRespBeacon));
	if (NULL == pBeaconStruct) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
			  "Unable to allocate memory in sap_compute_spect_weight");
		return;
	}
	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
		  "In %s, Computing spectral weight", __func__);

	/**
	 * Soft AP specific channel weight calculation using DFS formula
	 */
	SET_ACS_BAND(operatingBand, sap_ctx);

	pScanResult = sme_scan_result_get_first(halHandle, pResult);

	while (pScanResult) {
		pSpectCh = pSpectInfoParams->pSpectCh;
		/* Defining the default values, so that any value will hold the default values */
		channelWidth = eHT_CHANNEL_WIDTH_20MHZ;
		secondaryChannelOffset = PHY_SINGLE_CHANNEL_CENTERED;
		vhtSupport = 0;
		centerFreq = 0;

		if (pScanResult->BssDescriptor.ieFields != NULL) {
			ieLen =
				(pScanResult->BssDescriptor.length +
				 sizeof(uint16_t) + sizeof(uint32_t) -
				 sizeof(tSirBssDescription));
			qdf_mem_set((uint8_t *) pBeaconStruct,
				    sizeof(tSirProbeRespBeacon), 0);

			if ((sir_parse_beacon_ie
				     (pMac, pBeaconStruct, (uint8_t *)
				      (pScanResult->BssDescriptor.ieFields),
				      ieLen)) == eSIR_SUCCESS) {
				sap_upd_chan_spec_params(pBeaconStruct,
					&channelWidth, &secondaryChannelOffset,
					&vhtSupport, &centerFreq,
					&centerFreq_2);
			}
		}
		/* Processing for each tCsrScanResultInfo in the tCsrScanResult DLink list */
		for (chn_num = 0; chn_num < pSpectInfoParams->numSpectChans;
		     chn_num++) {

			/*
			 *  if the Beacon has channel ID, use it other wise we will
			 *  rely on the channelIdSelf
			 */
			if (pScanResult->BssDescriptor.channelId == 0)
				channel_id =
					pScanResult->BssDescriptor.channelIdSelf;
			else
				channel_id =
					pScanResult->BssDescriptor.channelId;

			if (pSpectCh && (channel_id == pSpectCh->chNum)) {
				if (pSpectCh->rssiAgr <
				    pScanResult->BssDescriptor.rssi)
					pSpectCh->rssiAgr =
						pScanResult->BssDescriptor.rssi;

				++pSpectCh->bssCount;   /* Increment the count of BSS */

				/*
				 * Connsidering the Extension Channel
				 * only in a channels
				 */
				switch (operatingBand) {
				case eCSR_DOT11_MODE_11a:
					sap_interference_rssi_count_5G(
					    pSpectCh, channelWidth,
					    secondaryChannelOffset,
					    centerFreq,
					    centerFreq_2,
					    channel_id);
					break;

				case eCSR_DOT11_MODE_11g:
					sap_interference_rssi_count(pSpectCh);
					break;

				case eCSR_DOT11_MODE_abg:
					sap_interference_rssi_count_5G(
					    pSpectCh, channelWidth,
					    secondaryChannelOffset,
					    centerFreq,
					    centerFreq_2,
					    channel_id);
					sap_interference_rssi_count(pSpectCh);
					break;
				}

				QDF_TRACE(QDF_MODULE_ID_SAP,
					  QDF_TRACE_LEVEL_INFO_HIGH,
					  "In %s, bssdes.ch_self=%d, bssdes.ch_ID=%d, bssdes.rssi=%d, SpectCh.bssCount=%d, pScanResult=%p, ChannelWidth %d, secondaryChanOffset %d, center frequency %d",
					  __func__,
					  pScanResult->BssDescriptor.
					  channelIdSelf,
					  pScanResult->BssDescriptor.channelId,
					  pScanResult->BssDescriptor.rssi,
					  pSpectCh->bssCount, pScanResult,
					  pSpectCh->channelWidth,
					  secondaryChannelOffset, centerFreq);
				pSpectCh++;
				break;
			} else {
				pSpectCh++;
			}
		}

		pScanResult = sme_scan_result_get_next(halHandle, pResult);
	}

	/* Calculate the weights for all channels in the spectrum pSpectCh */
	pSpectCh = pSpectInfoParams->pSpectCh;

	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
		  "In %s, Spectrum Channels Weight", __func__);

	for (chn_num = 0; chn_num < (pSpectInfoParams->numSpectChans);
	     chn_num++) {

		/*
		   rssi : Maximum received signal strength among all BSS on that channel
		   bssCount : Number of BSS on that channel
		 */

		rssi = (int8_t) pSpectCh->rssiAgr;
		if (ch_in_pcl(sap_ctx, chn_num))
			rssi -= PCL_RSSI_DISCOUNT;

		pSpectCh->weight =
			SAPDFS_NORMALISE_1000 * sapweight_rssi_count(rssi,
								     pSpectCh->
								     bssCount);
		pSpectCh->weight_copy = pSpectCh->weight;

		/* ------ Debug Info ------ */
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
			  "In %s, Chan=%d Weight= %d rssiAgr=%d bssCount=%d",
			  __func__, pSpectCh->chNum, pSpectCh->weight,
			  pSpectCh->rssiAgr, pSpectCh->bssCount);
		/* ------ Debug Info ------ */
		pSpectCh++;
	}
	qdf_mem_free(pBeaconStruct);
}

/*==========================================================================
   FUNCTION    sap_chan_sel_exit

   DESCRIPTION
    Exit function for free out the allocated memory, to be called
    at the end of the dfsSelectChannel function

   DEPENDENCIES
    NA.

   PARAMETERS

    IN
    pSpectInfoParams       : Pointer to the tSapChSelSpectInfo structure

   RETURN VALUE
    void     : NULL

   SIDE EFFECTS
   ============================================================================*/
static void sap_chan_sel_exit(tSapChSelSpectInfo *pSpectInfoParams)
{
	/* Free all the allocated memory */
	qdf_mem_free(pSpectInfoParams->pSpectCh);
}

/*==========================================================================
   FUNCTION    sap_sort_chl_weight

   DESCRIPTION
    Funtion to sort the channels with the least weight first for 20MHz channels

   DEPENDENCIES
    NA.

   PARAMETERS

    IN
    pSpectInfoParams       : Pointer to the tSapChSelSpectInfo structure

   RETURN VALUE
    void     : NULL

   SIDE EFFECTS
   ============================================================================*/
static void sap_sort_chl_weight(tSapChSelSpectInfo *pSpectInfoParams)
{
	tSapSpectChInfo temp;

	tSapSpectChInfo *pSpectCh = NULL;
	uint32_t i = 0, j = 0, minWeightIndex = 0;

	pSpectCh = pSpectInfoParams->pSpectCh;
	for (i = 0; i < pSpectInfoParams->numSpectChans; i++) {
		minWeightIndex = i;
		for (j = i + 1; j < pSpectInfoParams->numSpectChans; j++) {
			if (pSpectCh[j].weight <
			    pSpectCh[minWeightIndex].weight) {
				minWeightIndex = j;
			}
		}
		if (minWeightIndex != i) {
			qdf_mem_copy(&temp, &pSpectCh[minWeightIndex],
				     sizeof(*pSpectCh));
			qdf_mem_copy(&pSpectCh[minWeightIndex], &pSpectCh[i],
				     sizeof(*pSpectCh));
			qdf_mem_copy(&pSpectCh[i], &temp, sizeof(*pSpectCh));
		}
	}
}

/**
 * sap_sort_chl_weight_ht80() - to sort the channels with the least weight
 * @pSpectInfoParams: Pointer to the tSapChSelSpectInfo structure
 *
 * Funtion to sort the channels with the least weight first for HT80 channels
 *
 * Return: none
 */
static void sap_sort_chl_weight_ht80(tSapChSelSpectInfo *pSpectInfoParams)
{
	uint8_t i, j, n;
	tSapSpectChInfo *pSpectInfo;
	uint8_t minIdx;

	pSpectInfo = pSpectInfoParams->pSpectCh;
	/* for each HT80 channel, calculate the combined weight of the
	   four 20MHz weight */
	for (i = 0; i < ARRAY_SIZE(acs_ht80_channels); i++) {
		for (j = 0; j < pSpectInfoParams->numSpectChans; j++) {
			if (pSpectInfo[j].chNum ==
					acs_ht80_channels[i].chStartNum)
				break;
		}
		if (j == pSpectInfoParams->numSpectChans)
			continue;

		if (!(((pSpectInfo[j].chNum + 4) == pSpectInfo[j + 1].chNum) &&
			((pSpectInfo[j].chNum + 8) ==
				 pSpectInfo[j + 2].chNum) &&
			((pSpectInfo[j].chNum + 12) ==
				 pSpectInfo[j + 3].chNum))) {
			/*
			 * some channels does not exist in pSectInfo array,
			 * skip this channel and those in the same HT80 width
			 */
			pSpectInfo[j].weight = SAP_ACS_WEIGHT_MAX * 4;
			if ((pSpectInfo[j].chNum + 4) ==
					pSpectInfo[j + 1].chNum)
				pSpectInfo[j + 1].weight =
					SAP_ACS_WEIGHT_MAX * 4;
			if ((pSpectInfo[j].chNum + 8) ==
					pSpectInfo[j + 2].chNum)
				pSpectInfo[j + 2].weight =
					SAP_ACS_WEIGHT_MAX * 4;
			if ((pSpectInfo[j].chNum + 12) ==
					pSpectInfo[j + 3].chNum)
				pSpectInfo[j + 3].weight =
					SAP_ACS_WEIGHT_MAX * 4;
			continue;
		}
		/*found the channel, add the 4 adjacent channels' weight */
		acs_ht80_channels[i].weight = pSpectInfo[j].weight +
			pSpectInfo[j + 1].weight + pSpectInfo[j + 2].weight +
			pSpectInfo[j + 3].weight;
		/* find best channel among 4 channels as the primary channel */
		if ((pSpectInfo[j].weight + pSpectInfo[j + 1].weight) <
			(pSpectInfo[j + 2].weight + pSpectInfo[j + 3].weight)) {
			/* lower 2 channels are better choice */
			if (pSpectInfo[j].weight < pSpectInfo[j + 1].weight)
				minIdx = 0;
			else
				minIdx = 1;
		} else if (pSpectInfo[j + 2].weight <=
				pSpectInfo[j + 3].weight) {
			/* upper 2 channels are better choice */
			minIdx = 2;
		} else {
			minIdx = 3;
		}

		/*
		 * set all 4 channels to max value first, then reset the
		 * best channel as the selected primary channel, update its
		 * weightage with the combined weight value
		 */
		for (n = 0; n < 4; n++)
			pSpectInfo[j + n].weight = SAP_ACS_WEIGHT_MAX * 4;

		pSpectInfo[j + minIdx].weight = acs_ht80_channels[i].weight;
	}

	pSpectInfo = pSpectInfoParams->pSpectCh;
	for (j = 0; j < pSpectInfoParams->numSpectChans; j++) {
		if (CHANNEL_165 == pSpectInfo[j].chNum) {
			pSpectInfo[j].weight = SAP_ACS_WEIGHT_MAX * 4;
			break;
		}
	}

	sap_sort_chl_weight(pSpectInfoParams);

	pSpectInfo = pSpectInfoParams->pSpectCh;
	for (j = 0; j < (pSpectInfoParams->numSpectChans); j++) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
			FL("Channel=%d Weight= %d rssi=%d bssCount=%d"),
			pSpectInfo->chNum, pSpectInfo->weight,
			pSpectInfo->rssiAgr, pSpectInfo->bssCount);
		pSpectInfo++;
	}
}

/**
 * sap_sort_chl_weight_vht160() - to sort the channels with the least weight
 * @pSpectInfoParams: Pointer to the tSapChSelSpectInfo structure
 *
 * Funtion to sort the channels with the least weight first for VHT160 channels
 *
 * Return: none
 */
static void sap_sort_chl_weight_vht160(tSapChSelSpectInfo *pSpectInfoParams)
{
	uint8_t i, j, n, idx;
	tSapSpectChInfo *pSpectInfo;
	uint8_t minIdx;

	pSpectInfo = pSpectInfoParams->pSpectCh;
	/* for each VHT160 channel, calculate the combined weight of the
	   8 20MHz weight */
	for (i = 0; i < ARRAY_SIZE(acs_vht160_channels); i++) {
		for (j = 0; j < pSpectInfoParams->numSpectChans; j++) {
			if (pSpectInfo[j].chNum ==
					acs_vht160_channels[i].chStartNum)
				break;
		}
		if (j == pSpectInfoParams->numSpectChans)
			continue;

		if (!(((pSpectInfo[j].chNum + 4) == pSpectInfo[j + 1].chNum) &&
			((pSpectInfo[j].chNum + 8) ==
				 pSpectInfo[j + 2].chNum) &&
			((pSpectInfo[j].chNum + 12) ==
				 pSpectInfo[j + 3].chNum) &&
			((pSpectInfo[j].chNum + 16) ==
				 pSpectInfo[j + 4].chNum) &&
			((pSpectInfo[j].chNum + 20) ==
				 pSpectInfo[j + 5].chNum) &&
			((pSpectInfo[j].chNum + 24) ==
				 pSpectInfo[j + 6].chNum) &&
			((pSpectInfo[j].chNum + 28) ==
				 pSpectInfo[j + 7].chNum))) {
			/*
			 * some channels does not exist in pSectInfo array,
			 * skip this channel and those in the same VHT160 width
			 */
			pSpectInfo[j].weight = SAP_ACS_WEIGHT_MAX * 8;
			if ((pSpectInfo[j].chNum + 4) ==
					pSpectInfo[j + 1].chNum)
				pSpectInfo[j + 1].weight =
					SAP_ACS_WEIGHT_MAX * 8;
			if ((pSpectInfo[j].chNum + 8) ==
					pSpectInfo[j + 2].chNum)
				pSpectInfo[j + 2].weight =
					SAP_ACS_WEIGHT_MAX * 8;
			if ((pSpectInfo[j].chNum + 12) ==
					pSpectInfo[j + 3].chNum)
				pSpectInfo[j + 3].weight =
					SAP_ACS_WEIGHT_MAX * 8;
			if ((pSpectInfo[j].chNum + 16) ==
					pSpectInfo[j + 4].chNum)
				pSpectInfo[j + 4].weight =
					SAP_ACS_WEIGHT_MAX * 8;
			if ((pSpectInfo[j].chNum + 20) ==
					pSpectInfo[j + 5].chNum)
				pSpectInfo[j + 5].weight =
					SAP_ACS_WEIGHT_MAX * 8;
			if ((pSpectInfo[j].chNum + 24) ==
					pSpectInfo[j + 6].chNum)
				pSpectInfo[j + 6].weight =
					SAP_ACS_WEIGHT_MAX * 8;
			if ((pSpectInfo[j].chNum + 28) ==
					pSpectInfo[j + 7].chNum)
				pSpectInfo[j + 7].weight =
					SAP_ACS_WEIGHT_MAX * 8;
			continue;
		}
		/*found the channel, add the 7 adjacent channels' weight */
		acs_vht160_channels[i].weight = pSpectInfo[j].weight +
			pSpectInfo[j + 1].weight + pSpectInfo[j + 2].weight +
			pSpectInfo[j + 3].weight + pSpectInfo[j + 4].weight +
			pSpectInfo[j + 5].weight + pSpectInfo[j + 6].weight +
			pSpectInfo[j + 7].weight;

		/* find best channel among 8 channels as the primary channel */
		if ((pSpectInfo[j].weight + pSpectInfo[j + 1].weight +
			pSpectInfo[j + 2].weight + pSpectInfo[j + 3].weight) >
			(pSpectInfo[j + 4].weight + pSpectInfo[j + 5].weight +
			pSpectInfo[j + 6].weight + pSpectInfo[j + 7].weight))
			idx = 4;
		else
			idx = 0;
		/* find best channel among 4 channels as the primary channel */
		if ((pSpectInfo[j + idx].weight +
					pSpectInfo[j + idx + 1].weight) <
			(pSpectInfo[j + idx + 2].weight +
			 pSpectInfo[j + idx + 3].weight)) {
			/* lower 2 channels are better choice */
			if (pSpectInfo[j + idx].weight <
					pSpectInfo[j + idx + 1].weight)
				minIdx = 0 + idx;
			else
				minIdx = 1 + idx;
		} else if (pSpectInfo[j + idx + 2].weight <=
				pSpectInfo[j + idx + 3].weight) {
			/* upper 2 channels are better choice */
			minIdx = 2 + idx;
		} else {
			minIdx = 3 + idx;
		}

		/*
		 * set all 8 channels to max value first, then reset the
		 * best channel as the selected primary channel, update its
		 * weightage with the combined weight value
		 */
		for (n = 0; n < 8; n++)
			pSpectInfo[j + n].weight = SAP_ACS_WEIGHT_MAX * 8;

		pSpectInfo[j + minIdx].weight = acs_vht160_channels[i].weight;
	}

	pSpectInfo = pSpectInfoParams->pSpectCh;
	for (j = 0; j < pSpectInfoParams->numSpectChans; j++) {
		if (CHANNEL_165 == pSpectInfo[j].chNum) {
			pSpectInfo[j].weight = SAP_ACS_WEIGHT_MAX * 8;
			break;
		}
	}

	sap_sort_chl_weight(pSpectInfoParams);

	pSpectInfo = pSpectInfoParams->pSpectCh;
	for (j = 0; j < (pSpectInfoParams->numSpectChans); j++) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
			FL("Channel=%d Weight= %d rssi=%d bssCount=%d"),
			pSpectInfo->chNum, pSpectInfo->weight,
			pSpectInfo->rssiAgr, pSpectInfo->bssCount);
		pSpectInfo++;
	}
}

/**
 * sap_sort_chl_weight_ht40_24_g() - to sort channel with the least weight
 * @pSpectInfoParams: Pointer to the tSapChSelSpectInfo structure
 *
 * Funtion to sort the channels with the least weight first for HT40 channels
 *
 * Return: none
 */
static void sap_sort_chl_weight_ht40_24_g(tSapChSelSpectInfo *pSpectInfoParams)
{
	uint8_t i, j;
	tSapSpectChInfo *pSpectInfo;
	uint32_t tmpWeight1, tmpWeight2;

	pSpectInfo = pSpectInfoParams->pSpectCh;
	/*
	 * for each HT40 channel, calculate the combined weight of the
	 * two 20MHz weight
	 */
	for (i = 0; i < ARRAY_SIZE(acs_ht40_channels24_g); i++) {
		for (j = 0; j < pSpectInfoParams->numSpectChans; j++) {
			if (pSpectInfo[j].chNum ==
				acs_ht40_channels24_g[i].chStartNum)
				break;
		}
		if (j == pSpectInfoParams->numSpectChans)
			continue;

		if (!((pSpectInfo[j].chNum + 4) == pSpectInfo[j + 4].chNum)) {
			pSpectInfo[j].weight = SAP_ACS_WEIGHT_MAX * 2;
			continue;
		}
		/*
		 * check if there is another channel combination possiblity
		 * e.g., {1, 5} & {5, 9}
		 */
		if ((pSpectInfo[j + 4].chNum + 4) == pSpectInfo[j + 8].chNum) {
			/* need to compare two channel pairs */
			tmpWeight1 = pSpectInfo[j].weight +
						pSpectInfo[j + 4].weight;
			tmpWeight2 = pSpectInfo[j + 4].weight +
						pSpectInfo[j + 8].weight;
			if (tmpWeight1 <= tmpWeight2) {
				if (pSpectInfo[j].weight <=
						pSpectInfo[j + 4].weight) {
					pSpectInfo[j].weight =
						tmpWeight1;
					pSpectInfo[j + 4].weight =
						SAP_ACS_WEIGHT_MAX * 2;
					pSpectInfo[j + 8].weight =
						SAP_ACS_WEIGHT_MAX * 2;
				} else {
					pSpectInfo[j + 4].weight =
						tmpWeight1;
					/* for secondary channel selection */
					pSpectInfo[j].weight =
						SAP_ACS_WEIGHT_MAX * 2
						- 1;
					pSpectInfo[j + 8].weight =
						SAP_ACS_WEIGHT_MAX * 2;
				}
			} else {
				if (pSpectInfo[j + 4].weight <=
						pSpectInfo[j + 8].weight) {
					pSpectInfo[j + 4].weight =
						tmpWeight2;
					pSpectInfo[j].weight =
						SAP_ACS_WEIGHT_MAX * 2;
					/* for secondary channel selection */
					pSpectInfo[j + 8].weight =
						SAP_ACS_WEIGHT_MAX * 2
						- 1;
				} else {
					pSpectInfo[j + 8].weight =
						tmpWeight2;
					pSpectInfo[j].weight =
						SAP_ACS_WEIGHT_MAX * 2;
					pSpectInfo[j + 4].weight =
						SAP_ACS_WEIGHT_MAX * 2;
				}
			}
		} else {
			tmpWeight1 = pSpectInfo[j].weight +
						pSpectInfo[j + 4].weight;
			if (pSpectInfo[j].weight <=
					pSpectInfo[j + 4].weight) {
				pSpectInfo[j].weight = tmpWeight1;
				pSpectInfo[j + 4].weight =
					SAP_ACS_WEIGHT_MAX * 2;
			} else {
				pSpectInfo[j + 4].weight = tmpWeight1;
				pSpectInfo[j].weight =
					SAP_ACS_WEIGHT_MAX * 2;
			}
		}
	}
	sap_sort_chl_weight(pSpectInfoParams);
}

/*==========================================================================
   FUNCTION    sap_sort_chl_weight_ht40_5_g

   DESCRIPTION
    Funtion to sort the channels with the least weight first for HT40 channels

   DEPENDENCIES
    NA.

   PARAMETERS

    IN
    pSpectInfoParams       : Pointer to the tSapChSelSpectInfo structure

   RETURN VALUE
    void     : NULL

   SIDE EFFECTS
   ============================================================================*/
static void sap_sort_chl_weight_ht40_5_g(tSapChSelSpectInfo *pSpectInfoParams)
{
	uint8_t i, j;
	tSapSpectChInfo *pSpectInfo;

	pSpectInfo = pSpectInfoParams->pSpectCh;
	/*for each HT40 channel, calculate the combined weight of the
	   two 20MHz weight */
	for (i = 0; i < ARRAY_SIZE(acs_ht40_channels5_g); i++) {
		for (j = 0; j < pSpectInfoParams->numSpectChans; j++) {
			if (pSpectInfo[j].chNum ==
			    acs_ht40_channels5_g[i].chStartNum)
				break;
		}
		if (j == pSpectInfoParams->numSpectChans)
			continue;

		/* found the channel, add the two adjacent channels' weight */
		if ((pSpectInfo[j].chNum + 4) == pSpectInfo[j + 1].chNum) {
			acs_ht40_channels5_g[i].weight = pSpectInfo[j].weight +
						      pSpectInfo[j + 1].weight;
			/* select better of the adjact channel as the primary channel */
			if (pSpectInfo[j].weight <= pSpectInfo[j + 1].weight) {
				pSpectInfo[j].weight =
					acs_ht40_channels5_g[i].weight;
				/* mark the adjacent channel's weight as max value so
				   that it will be sorted to the bottom */
				pSpectInfo[j + 1].weight =
					SAP_ACS_WEIGHT_MAX * 2;
			} else {
				pSpectInfo[j + 1].weight =
					acs_ht40_channels5_g[i].weight;
				/* mark the adjacent channel's weight as max value so
				   that it will be sorted to the bottom */
				pSpectInfo[j].weight = SAP_ACS_WEIGHT_MAX * 2;
			}

		} else
			pSpectInfo[j].weight = SAP_ACS_WEIGHT_MAX * 2;
	}

	/* avoid channel 165 by setting its weight to max */
	pSpectInfo = pSpectInfoParams->pSpectCh;
	for (j = 0; j < pSpectInfoParams->numSpectChans; j++) {
		if (CHANNEL_165 == pSpectInfo[j].chNum) {
			pSpectInfo[j].weight = SAP_ACS_WEIGHT_MAX * 2;
			break;
		}
	}

	pSpectInfo = pSpectInfoParams->pSpectCh;
	for (j = 0; j < (pSpectInfoParams->numSpectChans); j++) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
			  "In %s, Channel=%d Weight= %d rssi=%d bssCount=%d",
			  __func__, pSpectInfo->chNum, pSpectInfo->weight,
			  pSpectInfo->rssiAgr, pSpectInfo->bssCount);
		pSpectInfo++;
	}

	sap_sort_chl_weight(pSpectInfoParams);
}

/*==========================================================================
   FUNCTION    sap_sort_chl_weight_all

   DESCRIPTION
    Funtion to sort the channels with the least weight first

   DEPENDENCIES
    NA.

   PARAMETERS

    IN
    ptSapContext           : Pointer to the ptSapContext structure
    pSpectInfoParams       : Pointer to the tSapChSelSpectInfo structure

   RETURN VALUE
    void     : NULL

   SIDE EFFECTS
   ============================================================================*/
static void sap_sort_chl_weight_all(ptSapContext pSapCtx,
				    tSapChSelSpectInfo *pSpectInfoParams,
				    uint32_t operatingBand)
{
	tSapSpectChInfo *pSpectCh = NULL;
	uint32_t j = 0;
#ifndef SOFTAP_CHANNEL_RANGE
	uint32_t i = 0;
#endif

	pSpectCh = pSpectInfoParams->pSpectCh;
#ifdef SOFTAP_CHANNEL_RANGE

	switch (pSapCtx->acs_cfg->ch_width) {
	case CH_WIDTH_40MHZ:
		if (eCSR_DOT11_MODE_11g == operatingBand)
			sap_sort_chl_weight_ht40_24_g(pSpectInfoParams);
		else if (eCSR_DOT11_MODE_11a == operatingBand)
			sap_sort_chl_weight_ht40_5_g(pSpectInfoParams);
		else {
			sap_sort_chl_weight_ht40_24_g(pSpectInfoParams);
			sap_sort_chl_weight_ht40_5_g(pSpectInfoParams);
		}
		break;
	case CH_WIDTH_80MHZ:
	case CH_WIDTH_80P80MHZ:
		sap_sort_chl_weight_ht80(pSpectInfoParams);
		break;
	case CH_WIDTH_160MHZ:
		sap_sort_chl_weight_vht160(pSpectInfoParams);
		break;
	case CH_WIDTH_20MHZ:
	default:
		/* Sorting the channels as per weights as 20MHz channels */
		sap_sort_chl_weight(pSpectInfoParams);
	}

#else
	/* Sorting the channels as per weights */
	for (i = 0; i < SPECT_24GHZ_CH_COUNT; i++) {
		minWeightIndex = i;
		for (j = i + 1; j < SPECT_24GHZ_CH_COUNT; j++) {
			if (pSpectCh[j].weight <
			    pSpectCh[minWeightIndex].weight) {
				minWeightIndex = j;
			}
		}
		if (minWeightIndex != i) {
			qdf_mem_copy(&temp, &pSpectCh[minWeightIndex],
				     sizeof(*pSpectCh));
			qdf_mem_copy(&pSpectCh[minWeightIndex], &pSpectCh[i],
				     sizeof(*pSpectCh));
			qdf_mem_copy(&pSpectCh[i], &temp, sizeof(*pSpectCh));
		}
	}
#endif

	/* For testing */
	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
		  "In %s, Sorted Spectrum Channels Weight", __func__);
	pSpectCh = pSpectInfoParams->pSpectCh;
	for (j = 0; j < (pSpectInfoParams->numSpectChans); j++) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
			  "In %s, Channel=%d Weight= %d rssi=%d bssCount=%d",
			  __func__, pSpectCh->chNum, pSpectCh->weight,
			  pSpectCh->rssiAgr, pSpectCh->bssCount);
		pSpectCh++;
	}

}

/*==========================================================================
   FUNCTION    sap_filter_over_lap_ch

   DESCRIPTION
    return true if ch is acceptable.
    This function will decide if we will filter over lap channel or not.

   DEPENDENCIES
    shall called after ap start.

   PARAMETERS

   IN
    pSapCtx          : Pointer to ptSapContext.
    chNum             : Filter channel number.

   RETURN VALUE
    bool          : true if channel is accepted.

   SIDE EFFECTS
   ============================================================================*/
static bool sap_filter_over_lap_ch(ptSapContext pSapCtx, uint16_t chNum)
{
	if (pSapCtx->enableOverLapCh)
		return eSAP_TRUE;
	else if ((chNum == CHANNEL_1) ||
		 (chNum == CHANNEL_6) || (chNum == CHANNEL_11))
		return eSAP_TRUE;

	return eSAP_FALSE;
}

/**
 * sap_select_channel_no_scan_result() - select SAP channel when no scan results
 * are available.
 * @sap_ctx: Sap context
 *
 * Returns: channel number if success, 0 otherwise
 */
static uint8_t sap_select_channel_no_scan_result(tHalHandle hal,
						ptSapContext sap_ctx)
{
	uint32_t start_ch_num, end_ch_num;
#ifdef FEATURE_WLAN_CH_AVOID
	enum channel_state ch_type;
	uint8_t i, first_safe_ch_in_range = SAP_CHANNEL_NOT_SELECTED;
#endif
	uint32_t dfs_master_cap_enabled;
	start_ch_num = sap_ctx->acs_cfg->start_ch;
	end_ch_num = sap_ctx->acs_cfg->end_ch;

	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
		  FL("start - end: %d - %d"), start_ch_num, end_ch_num);

#ifndef FEATURE_WLAN_CH_AVOID
	sap_ctx->acs_cfg->pri_ch = start_ch_num;
	sap_ctx->acs_cfg->ht_sec_ch = 0;
	/* pick the first channel in configured range */
	return start_ch_num;
#else
	sme_cfg_get_int(hal, WNI_CFG_DFS_MASTER_ENABLED,
				&dfs_master_cap_enabled);

	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
		"%s: dfs_master %x", __func__, dfs_master_cap_enabled);

	/* get a channel in PCL and within the range */
	for (i = 0; i < sap_ctx->acs_cfg->pcl_ch_count; i++) {
		if ((sap_ctx->acs_cfg->pcl_channels[i] < start_ch_num) ||
		    (sap_ctx->acs_cfg->pcl_channels[i] > end_ch_num))
			continue;

		first_safe_ch_in_range = sap_ctx->acs_cfg->pcl_channels[i];
		break;
	}

	if (SAP_CHANNEL_NOT_SELECTED != first_safe_ch_in_range)
		return first_safe_ch_in_range;

	for (i = 0; i < NUM_CHANNELS; i++) {
		if ((safe_channels[i].channelNumber < start_ch_num) ||
		    (safe_channels[i].channelNumber > end_ch_num))
			continue;

		ch_type = cds_get_channel_state(safe_channels[i].channelNumber);

		if ((ch_type == CHANNEL_STATE_DISABLE) ||
			(ch_type == CHANNEL_STATE_INVALID))
			continue;
		if ((!dfs_master_cap_enabled) &&
			(CHANNEL_STATE_DFS == ch_type)) {
			QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
				"%s: DFS master mode disabled. Skip DFS channel %d",
				__func__, safe_channels[i].channelNumber);
			continue;
		}
		if ((sap_ctx->dfs_mode == ACS_DFS_MODE_DISABLE) &&
		    (CHANNEL_STATE_DFS == ch_type))
			continue;

		if (safe_channels[i].isSafe == true) {
			QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
				FL("channel %d in the configuration is safe"),
				safe_channels[i].channelNumber);
			first_safe_ch_in_range = safe_channels[i].channelNumber;
			break;
		}

		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
			FL("channel %d in the configuration is unsafe"),
			safe_channels[i].channelNumber);
	}

	/* if no channel selected return SAP_CHANNEL_NOT_SELECTED */
	return first_safe_ch_in_range;
#endif /* !FEATURE_WLAN_CH_AVOID */
}

/**
 * sap_select_channel() - select SAP channel
 * @hal: Pointer to HAL handle
 * @sap_ctx: Sap context
 * @scan_result: Pointer to tScanResultHandle
 *
 * Runs a algorithm to select the best channel to operate in based on BSS
 * rssi and bss count on each channel
 *
 * Returns: channel number if success, 0 otherwise
 */
uint8_t sap_select_channel(tHalHandle hal, ptSapContext sap_ctx,
			   tScanResultHandle scan_result)
{
	/* DFS param object holding all the data req by the algo */
	tSapChSelSpectInfo spect_info_obj = { NULL, 0 };
	tSapChSelSpectInfo *spect_info = &spect_info_obj;
	uint8_t best_ch_num = SAP_CHANNEL_NOT_SELECTED;
#ifdef SOFTAP_CHANNEL_RANGE
	uint8_t count;
	uint32_t start_ch_num, end_ch_num, tmp_ch_num, operating_band = 0;
#endif
	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
		  "In %s, Running SAP Ch Select", __func__);

#ifdef FEATURE_WLAN_CH_AVOID
	sap_update_unsafe_channel_list(sap_ctx);
#endif

	if (NULL == scan_result) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
			  FL("No external AP present"));

#ifndef SOFTAP_CHANNEL_RANGE
		return SAP_CHANNEL_NOT_SELECTED;
#else
		return sap_select_channel_no_scan_result(hal, sap_ctx);
#endif
	}

	/* Initialize the structure pointed by spect_info */
	if (sap_chan_sel_init(hal, spect_info, sap_ctx) != eSAP_TRUE) {
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_ERROR,
			  FL("Ch Select initialization failed"));
		return SAP_CHANNEL_NOT_SELECTED;
	}
	/* Compute the weight of the entire spectrum in the operating band */
	sap_compute_spect_weight(spect_info, hal, scan_result, sap_ctx);

#ifdef FEATURE_AP_MCC_CH_AVOIDANCE
	/* process avoid channel IE to collect all channels to avoid */
	sap_process_avoid_ie(hal, sap_ctx, scan_result, spect_info);
#endif /* FEATURE_AP_MCC_CH_AVOIDANCE */

#ifdef SOFTAP_CHANNEL_RANGE
	start_ch_num = sap_ctx->acs_cfg->start_ch;
	end_ch_num = sap_ctx->acs_cfg->end_ch;
	SET_ACS_BAND(operating_band, sap_ctx);

	sap_ctx->acsBestChannelInfo.channelNum = 0;
	sap_ctx->acsBestChannelInfo.weight = SAP_ACS_WEIGHT_MAX;

	/* Sort the ch lst as per the computed weights, lesser weight first. */
	sap_sort_chl_weight_all(sap_ctx, spect_info, operating_band);

	/*Loop till get the best channel in the given range */
	for (count = 0; count < spect_info->numSpectChans; count++) {
		if ((start_ch_num > spect_info->pSpectCh[count].chNum) ||
		    (end_ch_num < spect_info->pSpectCh[count].chNum))
			continue;

		if (best_ch_num == SAP_CHANNEL_NOT_SELECTED) {
			best_ch_num = spect_info->pSpectCh[count].chNum;
			/* check if best_ch_num is in preferred channel list */
			best_ch_num =
				sap_select_preferred_channel_from_channel_list(
					best_ch_num, sap_ctx, spect_info);
			/* if not in preferred ch lst, go to nxt best ch */
			if (best_ch_num == SAP_CHANNEL_NOT_SELECTED)
				continue;

#ifdef FEATURE_AP_MCC_CH_AVOIDANCE
			/*
			 * Weight of the channels(device's AP is operating)
			 * increased to MAX+1 so that they will be choosen only
			 * when there is no other best channel to choose
			 */
			if (sap_check_in_avoid_ch_list(sap_ctx, best_ch_num)) {
				best_ch_num = SAP_CHANNEL_NOT_SELECTED;
				continue;
			}
#endif

			sap_ctx->acsBestChannelInfo.channelNum = best_ch_num;
			sap_ctx->acsBestChannelInfo.weight =
					spect_info->pSpectCh[count].weight_copy;
		}

		if (best_ch_num == SAP_CHANNEL_NOT_SELECTED)
			continue;

		if (operating_band != eCSR_DOT11_MODE_11g)
			continue;

		/* Give preference to Non-overlap channels */
		if (false == sap_filter_over_lap_ch(sap_ctx,
				spect_info->pSpectCh[count].chNum))
			continue;

		tmp_ch_num = spect_info->pSpectCh[count].chNum;
		tmp_ch_num = sap_select_preferred_channel_from_channel_list(
					tmp_ch_num, sap_ctx, spect_info);
		if (tmp_ch_num == SAP_CHANNEL_NOT_SELECTED)
			continue;

		best_ch_num = tmp_ch_num;
		break;
	}
#else
	/* Sort the ch lst as per the computed weights, lesser weight first. */
	sap_sort_chl_weight_all(sap_ctx, hal, spect_info);
	/* Get the first channel in sorted array as best 20M Channel */
	best_ch_num = (uint8_t) spect_info->pSpectCh[0].chNum;
	/* Select Best Channel from Channel List if Configured */
	best_ch_num = sap_select_preferred_channel_from_channel_list(
					best_ch_num, sap_ctx, spect_info);
#endif

	/*
	 * in case the best channel seleted is not in PCL and there is another
	 * channel which has same weightage and is in PCL, choose the one in
	 * PCL
	 */
	for (count = 0; count < spect_info->numSpectChans; count++) {
		if (!ch_in_pcl(sap_ctx, spect_info->pSpectCh[count].chNum) ||
		    (spect_info->pSpectCh[count].weight !=
				sap_ctx->acsBestChannelInfo.weight))
			continue;

		if (sap_select_preferred_channel_from_channel_list(
			spect_info->pSpectCh[count].chNum, sap_ctx, spect_info)
			== SAP_CHANNEL_NOT_SELECTED)
			continue;

#ifdef FEATURE_AP_MCC_CH_AVOIDANCE
		if (sap_check_in_avoid_ch_list(sap_ctx, best_ch_num))
			continue;
#endif
		best_ch_num = spect_info->pSpectCh[count].chNum;
		QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
			FL("change best channel to %d in PCL"), best_ch_num);
		break;
	}

	sap_ctx->acs_cfg->pri_ch = best_ch_num;
	/* determine secondary channel for 2.4G channel 5, 6, 7 in HT40 */
	if ((operating_band != eCSR_DOT11_MODE_11g) ||
	    (sap_ctx->acs_cfg->ch_width != CH_WIDTH_40MHZ))
		goto sap_ch_sel_end;

	if ((best_ch_num >= 5) && (best_ch_num <= 7)) {
		int weight_below, weight_above, i;
		tSapSpectChInfo *pspect_info;

		weight_below = weight_above = SAP_ACS_WEIGHT_MAX;
		pspect_info = spect_info->pSpectCh;
		for (i = 0; i < spect_info->numSpectChans; i++) {
			if (pspect_info[i].chNum == (best_ch_num - 4))
				weight_below = pspect_info[i].weight;
			if (pspect_info[i].chNum == (best_ch_num + 4))
				weight_above = pspect_info[i].weight;
		}

		if (weight_below < weight_above)
			sap_ctx->acs_cfg->ht_sec_ch =
					sap_ctx->acs_cfg->pri_ch - 4;
		else
			sap_ctx->acs_cfg->ht_sec_ch =
					sap_ctx->acs_cfg->pri_ch + 4;
	} else if (best_ch_num >= 1 && best_ch_num <= 4) {
		sap_ctx->acs_cfg->ht_sec_ch = sap_ctx->acs_cfg->pri_ch + 4;
	} else if (best_ch_num >= 8 && best_ch_num <= 13) {
		sap_ctx->acs_cfg->ht_sec_ch = sap_ctx->acs_cfg->pri_ch - 4;
	} else if (best_ch_num == 14) {
		sap_ctx->acs_cfg->ht_sec_ch = 0;
	}
	sap_ctx->secondary_ch = sap_ctx->acs_cfg->ht_sec_ch;

sap_ch_sel_end:
	/* Free all the allocated memory */
	sap_chan_sel_exit(spect_info);

	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
		  FL("Running SAP Ch select Completed, Ch=%d"), best_ch_num);
	if (best_ch_num > 0 && best_ch_num <= 252)
		return best_ch_num;
	else
		return SAP_CHANNEL_NOT_SELECTED;
}