mgmt/ap_selection.c

/******************************************************************************
 *
 * This file is provided under a dual license.  When you use or
 * distribute this software, you may choose to be licensed under
 * version 2 of the GNU General Public License ("GPLv2 License")
 * or BSD License.
 *
 * GPLv2 License
 *
 * Copyright(C) 2016 MediaTek Inc.
 *
 * 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 http://www.gnu.org/licenses/gpl-2.0.html for more details.
 *
 * BSD LICENSE
 *
 * Copyright(C) 2016 MediaTek Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  * Neither the name of the copyright holder nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *****************************************************************************/

#include "precomp.h"

/*
 * definition for AP selection algrithm
 */
#define BSS_FULL_SCORE                          (100)
#define CHNL_BSS_NUM_THRESOLD                   100
#define BSS_STA_CNT_THRESOLD                    30
#define SCORE_PER_AP                            1
#define ROAMING_NO_SWING_SCORE_STEP             100
/* MCS9 at BW 160 requires rssi at least -48dbm */
#define BEST_RSSI                               -48
/* MCS7 at 20BW, MCS5 at 40BW, MCS4 at 80BW, MCS3 at 160BW */
#define GOOD_RSSI_FOR_HT_VHT                    -64
/* Link speed 1Mbps need at least rssi -94dbm for 2.4G */
#define MINIMUM_RSSI_2G4                        -94
/* Link speed 6Mbps need at least rssi -86dbm for 5G */
#define MINIMUM_RSSI_5G                         -86

/* Real Rssi of a Bss may range in current_rssi - 5 dbm
 *to current_rssi + 5 dbm
 */
#define RSSI_DIFF_BETWEEN_BSS                   10 /* dbm */
#define LOW_RSSI_FOR_5G_BAND                    -70 /* dbm */
#define HIGH_RSSI_FOR_5G_BAND                   -60 /* dbm */

#define WEIGHT_IDX_CHNL_UTIL                    2
#define WEIGHT_IDX_SNR                          3
#define WEIGHT_IDX_RSSI                         2
#define WEIGHT_IDX_SCN_MISS_CNT                 2
#define WEIGHT_IDX_PROBE_RSP                    1
#define WEIGHT_IDX_CLIENT_CNT                   1
#define WEIGHT_IDX_AP_NUM                       2
#define WEIGHT_IDX_5G_BAND                      0
#define WEIGHT_IDX_BAND_WIDTH                   1
#define WEIGHT_IDX_STBC                         1
#define WEIGHT_IDX_DEAUTH_LAST                  4
#define WEIGHT_IDX_BLACK_LIST                   2
#if CFG_SUPPORT_RSN_SCORE
#define WEIGHT_IDX_RSN							2
#endif
#define WEIGHT_IDX_SAA							2


#define CALCULATE_SCORE_BY_PROBE_RSP(prBssDesc) \
	(WEIGHT_IDX_PROBE_RSP * \
	(prBssDesc->fgSeenProbeResp ? BSS_FULL_SCORE : 0))

#define CALCULATE_SCORE_BY_MISS_CNT(prAdapter, prBssDesc) \
	(WEIGHT_IDX_SCN_MISS_CNT * \
	(prAdapter->rWifiVar.rScanInfo.u4ScanUpdateIdx - \
	prBssDesc->u4UpdateIdx > 3 ? 0 : \
	(BSS_FULL_SCORE - (prAdapter->rWifiVar.rScanInfo.u4ScanUpdateIdx - \
	prBssDesc->u4UpdateIdx) * 25)))

#define CALCULATE_SCORE_BY_BAND(prAdapter, prBssDesc, cRssi) \
	(WEIGHT_IDX_5G_BAND * \
	((prBssDesc->eBand == BAND_5G && prAdapter->fgEnable5GBand && \
	cRssi > -70) ? BSS_FULL_SCORE : 0))

#define CALCULATE_SCORE_BY_STBC(prAdapter, prBssDesc) \
	(WEIGHT_IDX_STBC * \
	(prBssDesc->fgMultiAnttenaAndSTBC ? BSS_FULL_SCORE:0))

#define CALCULATE_SCORE_BY_DEAUTH(prBssDesc) \
	(WEIGHT_IDX_DEAUTH_LAST * \
	(prBssDesc->fgDeauthLastTime ? 0:BSS_FULL_SCORE))

#if CFG_SUPPORT_RSN_SCORE
#define CALCULATE_SCORE_BY_RSN(prBssDesc) \
	(WEIGHT_IDX_RSN * (prBssDesc->fgIsRSNSuitableBss ? BSS_FULL_SCORE:0))
#endif

/* Channel Utilization: weight index will be */
static uint16_t scanCalculateScoreByChnlInfo(
	struct AIS_SPECIFIC_BSS_INFO *prAisSpecificBssInfo, uint8_t ucChannel)
{
	struct ESS_CHNL_INFO *prEssChnlInfo = &prAisSpecificBssInfo->
		arCurEssChnlInfo[0];
	uint8_t i = 0;
	uint16_t u2Score = 0;

	for (; i < prAisSpecificBssInfo->ucCurEssChnlInfoNum; i++) {
		if (ucChannel == prEssChnlInfo[i].ucChannel) {
#if 0	/* currently, we don't take channel utilization into account */
			/* the channel utilization max value is 255.
			 *great utilization means little weight value.
			 * the step of weight value is 2.6
			 */
			u2Score = WEIGHT_IDX_CHNL_UTIL *
				(BSS_FULL_SCORE -
				(prEssChnlInfo[i].ucUtilization * 10 / 26));
#endif
			/* if AP num on this channel is greater than 100,
			 * the weight will be 0.
			 * otherwise, the weight value decrease 1
			 * if AP number increase 1
			 */
			if (prEssChnlInfo[i].ucApNum <= CHNL_BSS_NUM_THRESOLD)
				u2Score += WEIGHT_IDX_AP_NUM * (BSS_FULL_SCORE -
					prEssChnlInfo[i].ucApNum *
					SCORE_PER_AP);
			log_dbg(SCN, TRACE, "channel %d, AP num %d\n",
				ucChannel, prEssChnlInfo[i].ucApNum);
			break;
		}
	}
	return u2Score;
}

static uint16_t scanCalculateScoreByBandwidth(struct ADAPTER *prAdapter,
	struct BSS_DESC *prBssDesc)
{
	uint16_t u2Score = 0;

	if (prBssDesc->fgIsHTPresent) {
		if (prBssDesc->eBand == BAND_2G4)
			u2Score = (prBssDesc->eSco == 0) ? 60:100;
		else if (prBssDesc->eBand == BAND_5G)
			u2Score = (prBssDesc->eSco == 0) ? 60:100;
	} else if (prBssDesc->u2BSSBasicRateSet & RATE_SET_OFDM)
		u2Score = 20;
	else
		u2Score = 10;

	log_dbg(SCN, TRACE, "ht %d, eband %d, esco %d, u2Score %d\n",
		prBssDesc->fgIsHTPresent, prBssDesc->eBand, prBssDesc->eSco,
		u2Score);

	return u2Score * WEIGHT_IDX_BAND_WIDTH;
}

static uint16_t scanCalculateScoreByClientCnt(struct BSS_DESC *prBssDesc)
{
	uint16_t u2Score = 0;

	log_dbg(SCN, TRACE, "Exist bss load %d, sta cnt %d\n",
			prBssDesc->fgExsitBssLoadIE, prBssDesc->u2StaCnt);

	if (!prBssDesc->fgExsitBssLoadIE || prBssDesc->u2StaCnt >
		BSS_STA_CNT_THRESOLD)
		return 0;

	u2Score = BSS_FULL_SCORE - prBssDesc->u2StaCnt * 3;
	return u2Score * WEIGHT_IDX_CLIENT_CNT;
}

#if CFG_SUPPORT_802_11V_BSS_TRANSITION_MGT
struct NEIGHBOR_AP_T *scanGetNeighborAPEntry(struct LINK *prNeighborApLink,
					     uint8_t *pucBssid)
{
	struct NEIGHBOR_AP_T *prNeighborAP = NULL;

	LINK_FOR_EACH_ENTRY(prNeighborAP, prNeighborApLink, rLinkEntry,
			    struct NEIGHBOR_AP_T)
	{
		if (EQUAL_MAC_ADDR(prNeighborAP->aucBssid, pucBssid))
			return prNeighborAP;
	}
	return NULL;
}

u_int8_t scanPreferenceIsZero(struct ADAPTER *prAdapter, uint8_t *pucBssid)
{
	struct LINK *prNeighborAPLink = &prAdapter->rWifiVar.rAisSpecificBssInfo
						 .rNeighborApList.rUsingLink;
	struct NEIGHBOR_AP_T *prNeighborAP = NULL;

	if (prNeighborAPLink->u4NumElem == 0)
		return FALSE;

	prNeighborAP = scanGetNeighborAPEntry(prNeighborAPLink, pucBssid);

	if (prNeighborAP == NULL)
		return FALSE;
	if (!prNeighborAP->fgPrefPresence)
		return FALSE;
	if (prNeighborAP->ucPreference > 0)
		return FALSE;

	return TRUE;
}
#endif

static u_int8_t scanNeedReplaceCandidate(struct ADAPTER *prAdapter,
	struct BSS_DESC *prCandBss, struct BSS_DESC *prCurrBss,
	uint16_t u2CandScore, uint16_t u2CurrScore)
{
	int8_t cCandRssi = RCPI_TO_dBm(prCandBss->ucRCPI);
	int8_t cCurrRssi = RCPI_TO_dBm(prCurrBss->ucRCPI);
	uint32_t u4UpdateIdx = prAdapter->rWifiVar.rScanInfo.u4ScanUpdateIdx;
	uint16_t u2CandMiss = u4UpdateIdx - prCandBss->u4UpdateIdx;
	uint16_t u2CurrMiss = u4UpdateIdx - prCurrBss->u4UpdateIdx;

	/* 1. No need check score case
	 * 1.1 Scan missing count of CurrBss is too more,
	 * but Candidate is suitable, don't replace
	 */
	if (u2CurrMiss > 2 && u2CurrMiss > u2CandMiss) {
		log_dbg(SCN, INFO, "Scan Miss count of CurrBss > 2, and Candidate <= 2\n");
		return FALSE;
	}
	/* 1.2 Scan missing count of Candidate is too more,
	 * but CurrBss is suitable, replace
	 */
	if (u2CandMiss > 2 && u2CandMiss > u2CurrMiss) {
		log_dbg(SCN, INFO, "Scan Miss count of Candidate > 2, and CurrBss <= 2\n");
		return TRUE;
	}
	/* 1.3 Hard connecting RSSI check */
	if ((prCurrBss->eBand == BAND_5G && cCurrRssi < MINIMUM_RSSI_5G) ||
		(prCurrBss->eBand == BAND_2G4 && cCurrRssi < MINIMUM_RSSI_2G4))
		return FALSE;
	else if ((prCandBss->eBand == BAND_5G && cCandRssi < MINIMUM_RSSI_5G) ||
		(prCandBss->eBand == BAND_2G4 && cCandRssi < MINIMUM_RSSI_2G4))
		return TRUE;

	/* 1.4 prefer to select 5G Bss if Rssi of a 5G band BSS is >= -60dbm */
	if (prCandBss->eBand != prCurrBss->eBand) {
		if (prCurrBss->eBand == BAND_5G) {
			/* Current AP is 5G, replace candidate
			 * AP of current AP is good.
			 */
			if (cCurrRssi >= HIGH_RSSI_FOR_5G_BAND ||
				(cCandRssi < HIGH_RSSI_FOR_5G_BAND &&
				cCurrRssi > LOW_RSSI_FOR_5G_BAND))
				return TRUE;
			else if (cCurrRssi < LOW_RSSI_FOR_5G_BAND &&
				cCurrRssi < cCandRssi)
				return FALSE;
		} else {
			/* Candidate AP is 5G, don't replace it
			 * if it's good enough.
			 */
			if (cCandRssi >= HIGH_RSSI_FOR_5G_BAND ||
				(cCurrRssi < HIGH_RSSI_FOR_5G_BAND &&
				cCandRssi > LOW_RSSI_FOR_5G_BAND))
				return FALSE;
			else if (cCandRssi < LOW_RSSI_FOR_5G_BAND &&
				cCandRssi < cCurrRssi)
				return TRUE;
		}
	}

	/* 1.5 RSSI of Current Bss is lower than Candidate, don't replace
	 * If the lower Rssi is greater than -59dbm,
	 * then no need check the difference
	 * Otherwise, if difference is greater than 10dbm, select the good RSSI
	 */
	if (cCandRssi - cCurrRssi >= RSSI_DIFF_BETWEEN_BSS)
		return FALSE;
	/* RSSI of Candidate Bss is lower than Current, replace */
	if (cCurrRssi - cCandRssi >= RSSI_DIFF_BETWEEN_BSS)
		return TRUE;

#if CFG_SUPPORT_802_11V_BSS_TRANSITION_MGT
	if (scanPreferenceIsZero(prAdapter, prCurrBss->aucBSSID)) {
		log_dbg(SCN, INFO,
			"BTM: %s[" MACSTR "] preference value is 0, skip it\n",
			prCurrBss->aucSSID, MAC2STR(prCurrBss->aucBSSID));
		return FALSE;
	}
#endif

	/* 2. Check Score */
	/* 2.1 Cases that no need to replace candidate */
	if (prCandBss->fgIsConnected) {
		if ((u2CandScore + ROAMING_NO_SWING_SCORE_STEP) >= u2CurrScore)
			return FALSE;
	} else if (prCurrBss->fgIsConnected) {
		if (u2CandScore >= (u2CurrScore + ROAMING_NO_SWING_SCORE_STEP))
			return FALSE;
	} else if (u2CandScore >= u2CurrScore)
		return FALSE;
	/* 2.2 other cases, replace candidate */
	return TRUE;
}

static u_int8_t scanSanityCheckBssDesc(struct ADAPTER *prAdapter,
	struct BSS_DESC *prBssDesc, enum ENUM_BAND eBand, uint8_t ucChannel,
		u_int8_t fgIsFixedChannel)
{
	if (!(prBssDesc->ucPhyTypeSet &
		(prAdapter->rWifiVar.ucAvailablePhyTypeSet))) {
		log_dbg(SCN, WARN,
			"SEARCH: Ignore unsupported ucPhyTypeSet = %x\n",
			prBssDesc->ucPhyTypeSet);
		return FALSE;
	}
	if (prBssDesc->fgIsUnknownBssBasicRate)
		return FALSE;
	if (fgIsFixedChannel &&
		(eBand != prBssDesc->eBand || ucChannel !=
		prBssDesc->ucChannelNum)) {
		log_dbg(SCN, INFO, "Fix channel required band %d, channel %d\n",
			eBand, ucChannel);
		return FALSE;
	}
	if (!rlmDomainIsLegalChannel(prAdapter, prBssDesc->eBand,
		prBssDesc->ucChannelNum)) {
		log_dbg(SCN, WARN, "Band %d channel %d is not legal\n",
			prBssDesc->eBand, prBssDesc->ucChannelNum);
		return FALSE;
	}

	if (CHECK_FOR_TIMEOUT(kalGetTimeTick(), prBssDesc->rUpdateTime,
		SEC_TO_SYSTIME(SCN_BSS_DESC_STALE_SEC))) {
		log_dbg(SCN, WARN, "BSS "
			MACSTR
			" description is too old.\n",
			MAC2STR(prBssDesc->aucBSSID));
		return FALSE;
	}

#if CFG_SUPPORT_WAPI
	if (prAdapter->rWifiVar.rConnSettings.fgWapiMode) {
		if (!wapiPerformPolicySelection(prAdapter, prBssDesc))
			return FALSE;
	} else
#endif
	if (!rsnPerformPolicySelection(prAdapter, prBssDesc))
		return FALSE;
	if (prAdapter->rWifiVar.rAisSpecificBssInfo.fgCounterMeasure) {
		log_dbg(SCN, WARN, "Skip while at counter measure period!!!\n");
		return FALSE;
	}
	return TRUE;
}

static uint16_t scanCalculateScoreByRssi(struct BSS_DESC *prBssDesc)
{
	uint16_t u2Score = 0;
	int8_t cRssi = RCPI_TO_dBm(prBssDesc->ucRCPI);

	if (cRssi >= -20)
		u2Score = BSS_FULL_SCORE;
	else if (cRssi >= -55)
		u2Score = 95;
	else if (cRssi >= -65)
		u2Score = 80;
	else if (cRssi >= -70)
		u2Score = 50;
	else if (cRssi >= -77)
		u2Score = 15;
	else if (cRssi >= -88)
		u2Score = 10;
	else if (cRssi < -88 && cRssi > -100)
		u2Score = 5;
	else if (cRssi <= -100)
		u2Score = 0;

	u2Score *= WEIGHT_IDX_RSSI;

	return u2Score;
}

static uint16_t scanCalculateScoreByBand(struct ADAPTER *prAdapter,
	struct BSS_DESC *prBssDesc, int8_t cRssi)
{
	uint16_t u2Score = 0;
	struct AIS_FSM_INFO *prAisFsmInfo;
#if CFG_SUPPORT_ROAMING
	struct ROAMING_INFO *prRoamingFsmInfo;
#endif
	prAisFsmInfo = &(prAdapter->rWifiVar.rAisFsmInfo);
#if CFG_SUPPORT_ROAMING
	prRoamingFsmInfo = (struct ROAMING_INFO *)
		&(prAdapter->rWifiVar.rRoamingInfo);
#endif
	if (prBssDesc->eBand == BAND_5G && prAdapter->fgEnable5GBand
		&& cRssi > -60
#if CFG_SUPPORT_ROAMING
		&& prRoamingFsmInfo->eCurrentState == ROAMING_STATE_IDLE
#endif
		&& prAisFsmInfo->u4PostponeIndStartTime == 0)
		u2Score = (WEIGHT_IDX_5G_BAND * BSS_FULL_SCORE);

	return u2Score;
}

static uint16_t scanCalculateScoreBySaa(struct ADAPTER *prAdapter,
	struct BSS_DESC *prBssDesc)
{
	uint16_t u2Score = 0;
	struct STA_RECORD *prStaRec = (struct STA_RECORD *) NULL;

	prStaRec = cnmGetStaRecByAddress(prAdapter, NETWORK_TYPE_AIS,
		prBssDesc->aucSrcAddr);
	if (prStaRec)
		u2Score = WEIGHT_IDX_SAA * (prStaRec->ucTxAuthAssocRetryCount
			? 0 : BSS_FULL_SCORE);
	else
		u2Score = WEIGHT_IDX_SAA * BSS_FULL_SCORE;

	return u2Score;
}

/*
 * Bss Characteristics to be taken into account when calculate Score:
 * Channel Loading Group:
 * 1. Client Count (in BSS Load IE).
 * 2. AP number on the Channel.
 *
 * RF Group:
 * 1. Channel utilization.
 * 2. SNR.
 * 3. RSSI.
 *
 * Misc Group:
 * 1. Deauth Last time.
 * 2. Scan Missing Count.
 * 3. Has probe response in scan result.
 *
 * Capability Group:
 * 1. Prefer 5G band.
 * 2. Bandwidth.
 * 3. STBC and Multi Anttena.
 */
struct BSS_DESC *scanSearchBssDescByScoreForAis(struct ADAPTER *prAdapter)
{
	struct AIS_SPECIFIC_BSS_INFO *prAisSpecificBssInfo = NULL;
	struct LINK *prEssLink = NULL;
	struct CONNECTION_SETTINGS *prConnSettings = NULL;
	struct BSS_DESC *prBssDesc = NULL;
	struct BSS_DESC *prCandBssDesc = NULL;
	struct BSS_DESC *prCandBssDescForLowRssi = NULL;
	uint16_t u2ScoreBand = 0;
	uint16_t u2ScoreChnlInfo = 0;
	uint16_t u2ScoreStaCnt = 0;
	uint16_t u2ScoreProbeRsp = 0;
	uint16_t u2ScoreScanMiss = 0;
	uint16_t u2ScoreBandwidth = 0;
	uint16_t u2ScoreSTBC = 0;
	uint16_t u2ScoreDeauth = 0;
	uint16_t u2ScoreRssi = 0;
	uint16_t u2ScoreTotal = 0;
	uint16_t u2ScoreRSN = 0;
	uint16_t u2ScoreSaa = 0;
	uint16_t u2CandBssScore = 0;
	uint16_t u2CandBssScoreForLowRssi = 0;
	uint16_t u2BlackListScore = 0;
	u_int8_t fgSearchBlackList = FALSE;
	u_int8_t fgIsFixedChannel = FALSE;
	enum ENUM_BAND eBand = BAND_2G4;
	uint8_t ucChannel = 0;
	int8_t cRssi = -128;

	if (!prAdapter) {
		log_dbg(SCN, ERROR, "prAdapter is NULL!\n");
		return NULL;
	}
	prAisSpecificBssInfo = &prAdapter->rWifiVar.rAisSpecificBssInfo;
	prConnSettings = &(prAdapter->rWifiVar.rConnSettings);
	prEssLink = &prAisSpecificBssInfo->rCurEssLink;
#if CFG_SUPPORT_CHNL_CONFLICT_REVISE
	fgIsFixedChannel = cnmAisDetectP2PChannel
		(prAdapter, &eBand, &ucChannel);
#else
	fgIsFixedChannel =
		cnmAisInfraChannelFixed(prAdapter, &eBand, &ucChannel);
#endif
	aisRemoveTimeoutBlacklist(prAdapter);
	log_dbg(SCN, INFO, "%s: ConnectionPolicy = %d\n",
		__func__,
		prConnSettings->eConnectionPolicy);

try_again:
	LINK_FOR_EACH_ENTRY(prBssDesc, prEssLink, rLinkEntryEss,
		struct BSS_DESC) {
		if (prConnSettings->eConnectionPolicy == CONNECT_BY_BSSID &&
			EQUAL_MAC_ADDR(prBssDesc->aucBSSID,
				prConnSettings->aucBSSID)) {
			if (!scanSanityCheckBssDesc(prAdapter, prBssDesc,
				eBand, ucChannel, fgIsFixedChannel))
				continue;

			/* Make sure to match with SSID if supplied.
			 * Some old dualband APs share a single BSSID
			 * among different BSSes.
			 */
			if ((prBssDesc->ucSSIDLen > 0 &&
				prConnSettings->ucSSIDLen > 0 &&
				EQUAL_SSID(prBssDesc->aucSSID,
					prBssDesc->ucSSIDLen,
					prConnSettings->aucSSID,
					prConnSettings->ucSSIDLen)) ||
				prConnSettings->ucSSIDLen == 0)
				log_dbg(SCN, LOUD, "%s: BSSID/SSID pair matched\n",
						__func__);
			else {
				log_dbg(SCN, ERROR, "%s: BSSID/SSID pair unmatched ("
					MACSTR
					")\n", __func__,
					MAC2STR(prBssDesc->aucBSSID));
				continue;
			}
			prCandBssDesc = prBssDesc;
			break;
		} else if (prConnSettings->eConnectionPolicy ==
			CONNECT_BY_BSSID_HINT &&
			EQUAL_MAC_ADDR(prBssDesc->aucBSSID,
				prConnSettings->aucBSSIDHint)) {
			if (!scanSanityCheckBssDesc(prAdapter, prBssDesc,
				eBand, ucChannel, fgIsFixedChannel))
				continue;

			prCandBssDesc = prBssDesc;
			break;
		}

		if (!fgSearchBlackList) {
			prBssDesc->prBlack =
				aisQueryBlackList(prAdapter, prBssDesc);
			if (prBssDesc->prBlack) {
				if (prBssDesc->prBlack->fgIsInFWKBlacklist ==
					TRUE)
					log_dbg(SCN, INFO, "%s("
						MACSTR
						") is in FWK blacklist, skip it\n",
						prBssDesc->aucSSID,
						MAC2STR(prBssDesc->aucBSSID));
				continue;
			}
		} else if (!prBssDesc->prBlack)
			continue;
		else {
			/* never search FWK blacklist even
			 * if we are trying blacklist
			 */
			if (prBssDesc->prBlack->fgIsInFWKBlacklist == TRUE) {
				log_dbg(SCN, INFO, "Although trying blacklist, %s("
					MACSTR
					") is in FWK blacklist, skip it\n",
					prBssDesc->aucSSID,
					MAC2STR(prBssDesc->aucBSSID));
				continue;
			}
			u2BlackListScore = WEIGHT_IDX_BLACK_LIST *
				aisCalculateBlackListScore(prAdapter,
					prBssDesc);
		}

		cRssi = RCPI_TO_dBm(prBssDesc->ucRCPI);

		if (!scanSanityCheckBssDesc(prAdapter, prBssDesc, eBand,
			ucChannel, fgIsFixedChannel))
			continue;

		u2ScoreBandwidth =
			scanCalculateScoreByBandwidth(prAdapter, prBssDesc);
		u2ScoreStaCnt = scanCalculateScoreByClientCnt(prBssDesc);
		u2ScoreSTBC = CALCULATE_SCORE_BY_STBC(prAdapter, prBssDesc);
		u2ScoreChnlInfo =
			scanCalculateScoreByChnlInfo(prAisSpecificBssInfo,
			prBssDesc->ucChannelNum);
		u2ScoreRssi = scanCalculateScoreByRssi(prBssDesc);
		u2ScoreDeauth = CALCULATE_SCORE_BY_DEAUTH(prBssDesc);
		u2ScoreProbeRsp = CALCULATE_SCORE_BY_PROBE_RSP(prBssDesc);
		u2ScoreScanMiss = CALCULATE_SCORE_BY_MISS_CNT(prAdapter,
			prBssDesc);
		u2ScoreBand = scanCalculateScoreByBand(prAdapter, prBssDesc,
			cRssi);
#if CFG_SUPPORT_RSN_SCORE
		u2ScoreRSN = CALCULATE_SCORE_BY_RSN(prBssDesc);
#endif
		u2ScoreSaa = scanCalculateScoreBySaa(prAdapter, prBssDesc);

		u2ScoreTotal = u2ScoreBandwidth + u2ScoreChnlInfo +
			u2ScoreDeauth + u2ScoreProbeRsp + u2ScoreScanMiss +
			u2ScoreRssi + u2ScoreStaCnt + u2ScoreSTBC +
			u2ScoreBand + u2BlackListScore + u2ScoreRSN +
			u2ScoreSaa;

		log_dbg(SCN, INFO,
			MACSTR
			" cRSSI[%d] 5G[%d] Score, Total %d, DE[%d], PR[%d], SM[%d], RSSI[%d], BA[%d] RSN[%d], SAA[%d], BW[%d], CN[%d], ST[%d], CI[%d]\n",
			MAC2STR(prBssDesc->aucBSSID), cRssi,
			(prBssDesc->eBand == BAND_5G ? 1 : 0), u2ScoreTotal,
			u2ScoreDeauth, u2ScoreProbeRsp, u2ScoreScanMiss,
			u2ScoreRssi, u2BlackListScore, u2ScoreRSN, u2ScoreSaa,
			u2ScoreBandwidth, u2ScoreStaCnt, u2ScoreSTBC,
			u2ScoreChnlInfo);

		if (!prCandBssDesc ||
			scanNeedReplaceCandidate(prAdapter, prCandBssDesc,
			prBssDesc, u2CandBssScore, u2ScoreTotal)) {
			prCandBssDesc = prBssDesc;
			u2CandBssScore = u2ScoreTotal;
		}
	}

	if (prCandBssDesc) {
		if (prCandBssDesc->fgIsConnected && !fgSearchBlackList &&
			prEssLink->u4NumElem > 0) {
			fgSearchBlackList = TRUE;
			log_dbg(SCN, INFO, "Can't roam out, try blacklist\n");
			goto try_again;
		}
		if (prConnSettings->eConnectionPolicy == CONNECT_BY_BSSID)
			log_dbg(SCN, INFO, "Selected "
				MACSTR
				" %d base on ssid,when find %s, "
				MACSTR
				" in %d bssid,fix channel %d.\n",
				MAC2STR(prCandBssDesc->aucBSSID),
				RCPI_TO_dBm(prCandBssDesc->ucRCPI),
				prConnSettings->aucSSID,
				MAC2STR(prConnSettings->aucBSSID),
				prEssLink->u4NumElem, ucChannel);
		else
			log_dbg(SCN, INFO,
				"Selected "
				MACSTR
				", cRSSI[%d] 5G[%d] Score %d when find %s, "
				MACSTR
				" in %d BSSes, fix channel %d.\n",
				MAC2STR(prCandBssDesc->aucBSSID),
				cRssi = RCPI_TO_dBm(prCandBssDesc->ucRCPI),
				(prCandBssDesc->eBand == BAND_5G ? 1 : 0),
				u2CandBssScore, prConnSettings->aucSSID,
				MAC2STR(prConnSettings->aucBSSID),
				prEssLink->u4NumElem, ucChannel);

		return prCandBssDesc;
	} else if (prCandBssDescForLowRssi) {
		log_dbg(SCN, INFO, "Selected " MACSTR
			", Score %d when find %s, " MACSTR
			" in %d BSSes, fix channel %d.\n",
			MAC2STR(prCandBssDescForLowRssi->aucBSSID),
			u2CandBssScoreForLowRssi, prConnSettings->aucSSID,
			MAC2STR(prConnSettings->aucBSSID), prEssLink->u4NumElem,
			ucChannel);
		return prCandBssDescForLowRssi;
	}

	/* if No Candidate BSS is found, try BSSes which are in blacklist */
	if (!fgSearchBlackList && prEssLink->u4NumElem > 0) {
		fgSearchBlackList = TRUE;
		log_dbg(SCN, INFO, "No Bss is found, Try blacklist\n");
		goto try_again;
	}
	log_dbg(SCN, INFO, "Selected None when find %s, " MACSTR
		" in %d BSSes, fix channel %d.\n",
		prConnSettings->aucSSID, MAC2STR(prConnSettings->aucBSSID),
		prEssLink->u4NumElem, ucChannel);
	return NULL;
}

void scanGetCurrentEssChnlList(struct ADAPTER *prAdapter)
{
	struct BSS_DESC *prBssDesc = NULL;
	struct LINK *prBSSDescList =
		&prAdapter->rWifiVar.rScanInfo.rBSSDescList;
	struct CONNECTION_SETTINGS *prConnSettings = &prAdapter->
		rWifiVar.rConnSettings;
	struct ESS_CHNL_INFO *prEssChnlInfo = &prAdapter->
		rWifiVar.rAisSpecificBssInfo.arCurEssChnlInfo[0];
	struct LINK *prCurEssLink = &prAdapter->
		rWifiVar.rAisSpecificBssInfo.rCurEssLink;
	uint8_t aucChnlBitMap[30] = {0,};
	uint8_t aucChnlApNum[215] = {0,};
	uint8_t aucChnlUtil[215] = {0,};
	uint8_t ucByteNum = 0;
	uint8_t ucBitNum = 0;
	uint8_t ucChnlCount = 0;
	uint8_t j = 0;

	if (prConnSettings->ucSSIDLen == 0) {
		log_dbg(SCN, INFO, "No Ess are expected to connect\n");
		return;
	}
	kalMemZero(prEssChnlInfo, CFG_MAX_NUM_OF_CHNL_INFO *
		sizeof(struct ESS_CHNL_INFO));
	while (!LINK_IS_EMPTY(prCurEssLink)) {
		prBssDesc =
LINK_PEEK_HEAD(prCurEssLink,
	struct BSS_DESC, rLinkEntryEss);
		LINK_REMOVE_KNOWN_ENTRY(prCurEssLink,
			&prBssDesc->rLinkEntryEss);
	}
	LINK_FOR_EACH_ENTRY(prBssDesc, prBSSDescList, rLinkEntry,
		struct BSS_DESC) {
		if (prBssDesc->ucChannelNum > 214)
			continue;
		/* Statistic AP num for each channel */
		if (aucChnlApNum[prBssDesc->ucChannelNum] < 255)
			aucChnlApNum[prBssDesc->ucChannelNum]++;
		if (aucChnlUtil[prBssDesc->ucChannelNum] <
			prBssDesc->ucChnlUtilization)
			aucChnlUtil[prBssDesc->ucChannelNum] =
				prBssDesc->ucChnlUtilization;
		if (!EQUAL_SSID(prConnSettings->aucSSID,
			prConnSettings->ucSSIDLen,
			prBssDesc->aucSSID, prBssDesc->ucSSIDLen))
			continue;
		/* Record same BSS list */
		LINK_INSERT_HEAD(prCurEssLink, &prBssDesc->rLinkEntryEss);
		ucByteNum = prBssDesc->ucChannelNum / 8;
		ucBitNum = prBssDesc->ucChannelNum % 8;
		if (aucChnlBitMap[ucByteNum] & BIT(ucBitNum))
			continue;
		aucChnlBitMap[ucByteNum] |= BIT(ucBitNum);
		prEssChnlInfo[ucChnlCount].ucChannel = prBssDesc->ucChannelNum;
		ucChnlCount++;
		if (ucChnlCount >= CFG_MAX_NUM_OF_CHNL_INFO)
			break;
	}
	prAdapter->rWifiVar.rAisSpecificBssInfo.ucCurEssChnlInfoNum =
		ucChnlCount;
	for (j = 0; j < ucChnlCount; j++) {
		uint8_t ucChnl = prEssChnlInfo[j].ucChannel;

		prEssChnlInfo[j].ucApNum = aucChnlApNum[ucChnl];
		prEssChnlInfo[j].ucUtilization = aucChnlUtil[ucChnl];
	}
#if 0
	/* Sort according to AP number */
	for (j = 0; j < ucChnlCount; j++) {
		for (i = j + 1; i < ucChnlCount; i++)
			if (prEssChnlInfo[j].ucApNum >
				prEssChnlInfo[i].ucApNum) {
				struct ESS_CHNL_INFO rTemp = prEssChnlInfo[j];

				prEssChnlInfo[j] = prEssChnlInfo[i];
				prEssChnlInfo[i] = rTemp;
			}
	}
#endif
	log_dbg(SCN, INFO, "Find %s in %d BSSes, result %d\n",
		prConnSettings->aucSSID, prBSSDescList->u4NumElem,
		prCurEssLink->u4NumElem);
}