qcacld: Add support for pre start BSS ACS to enable ACS+OBSS coex

Add support for enabling acs+obss co-existence before the
start bss is issued.

Change-Id: Id4a3519e01319c8066e615d76eb5c14f5988228d
CRs-Fixed: 752061

7 files changed, 816 insertions, 70 deletions

diff --git a/CORE/SAP/inc/sapApi.h b/CORE/SAP/inc/sapApi.h
index 48b18536de9d..42e5d3c84b6b 100644
--- a/CORE/SAP/inc/sapApi.h
+++ b/CORE/SAP/inc/sapApi.h
@@ -210,6 +210,7 @@ typedef enum {
 #ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
     eSAP_ACS_SCAN_SUCCESS_EVENT,
 #endif
+    eSAP_ACS_CHANNEL_SELECTED,
 } eSapHddEvent;
 
 typedef enum {
@@ -407,6 +408,11 @@ typedef struct sap_DfsNolInfo_s {
    v_PVOID_t pDfsList;       /* pointer to pDfsList buffer */
 } tSap_DfsNolInfo;
 
+typedef struct sap_AcsChSelected_s {
+   v_U8_t   pri_channel;
+   v_U8_t   sec_channel;
+} tSap_AcsChSelectedEvent;
+
 /*
    This struct will be filled in and passed to tpWLAN_SAPEventCB that is provided during WLANSAP_StartBss call
    The event id corresponding to structure  in the union is defined in comment next to the structure
@@ -432,6 +438,8 @@ typedef struct sap_Event_s {
         tSap_MaxAssocExceededEvent                sapMaxAssocExceeded; /* eSAP_MAX_ASSOC_EXCEEDED */
         tSap_OperatingChannelChangeEvent          sapChannelChange; /* eSAP_CHANNEL_CHANGE_EVENT */
         tSap_DfsNolInfo                           sapDfsNolInfo;    /*eSAP_DFS_NOL_XXX */
+        /*eSAP_ACS_CHANNEL_SELECTED */
+        tSap_AcsChSelectedEvent                   sapAcsChSelected;
     } sapevt;
 } tSap_Event, *tpSap_Event;
 
@@ -2323,6 +2331,39 @@ void WLANSAP_PopulateDelStaParams(const v_U8_t *mac,
                                   v_U16_t reason_code,
                                   v_U8_t subtype,
                                   struct tagCsrDelStaParams *pDelStaParams);
+
+/*==========================================================================
+  FUNCTION    WLANSAP_ACS_CHSelect
+
+  DESCRIPTION
+    This api function provides ACS selection for BSS
+
+  DEPENDENCIES
+    NA.
+
+  PARAMETERS
+
+    IN
+      pvosGCtx: Pointer to vos global context structure
+      pConfig: Pointer to configuration structure passed down from HDD
+      pACSEventCallback: Callback function in HDD called by SAP to inform
+                         HDD about channel section result
+      usrDataForCallback: Parameter that will be passed back in all the
+                          SAP callback events.
+
+  RETURN VALUE
+    The VOS_STATUS code associated with performing the operation
+
+    VOS_STATUS_SUCCESS:  Success
+
+  SIDE EFFECTS
+============================================================================*/
+VOS_STATUS
+WLANSAP_ACS_CHSelect(v_PVOID_t pvosGCtx,
+                     tpWLAN_SAPEventCB pACSEventCallback,
+                     tsap_Config_t *pConfig,
+                     v_PVOID_t  pUsrContext);
+
 #ifdef __cplusplus
  }
 #endif
diff --git a/CORE/SAP/src/sapApiLinkCntl.c b/CORE/SAP/src/sapApiLinkCntl.c
index a6970407d638..550563061596 100644
--- a/CORE/SAP/src/sapApiLinkCntl.c
+++ b/CORE/SAP/src/sapApiLinkCntl.c
@@ -274,6 +274,268 @@ WLANSAP_ScanCallback
 }// WLANSAP_ScanCallback
 
 /*==========================================================================
+
+  FUNCTION    WLANSAP_PreStartBssAcsScanCallback()
+
+  DESCRIPTION
+    Callback for Scan (scan results) Events
+
+  DEPENDENCIES
+    NA.
+
+  PARAMETERS
+
+    IN
+    tHalHandle:  the tHalHandle passed in with the scan request
+    *p2: the second context pass in for the caller, opaque sap Handle here
+    scanID:
+    sessionId: Session identifier
+    status: Status of scan -success, failure or abort
+
+  RETURN VALUE
+    The eHalStatus code associated with performing the operation
+
+    eHAL_STATUS_SUCCESS:  Success
+
+  SIDE EFFECTS
+
+============================================================================*/
+eHalStatus
+WLANSAP_PreStartBssAcsScanCallback
+(
+  tHalHandle halHandle,
+  void *pContext,
+  v_U8_t sessionId,
+  v_U32_t scanID,
+  eCsrScanStatus scanStatus
+)
+{
+    tScanResultHandle pResult = NULL;
+    eHalStatus scanGetResultStatus = eHAL_STATUS_FAILURE;
+    ptSapContext psapContext = (ptSapContext)pContext;
+    v_U8_t operChannel = 0;
+    VOS_STATUS vosStatus = VOS_STATUS_E_FAILURE;
+    eHalStatus halStatus = eHAL_STATUS_FAILURE;
+#ifdef SOFTAP_CHANNEL_RANGE
+    v_U32_t operatingBand;
+#endif
+    v_U32_t vhtChannelWidth;
+    tpAniSirGlobal    pMac = PMAC_STRUCT(halHandle);
+
+    if ( eCSR_SCAN_SUCCESS == scanStatus)
+    {
+        VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH,
+                   FL("CSR scanStatus = %s (%d)"),
+                   "eCSR_SCAN_SUCCESS", scanStatus);
+        /*
+         * Now do
+         * 1. Get scan results
+         * 2. Run channel selection algorithm
+         * select channel and store in pSapContext->Channel
+         */
+        scanGetResultStatus = sme_ScanGetResult(halHandle,
+                                                psapContext->sessionId,
+                                                NULL, &pResult);
+
+        if ((scanGetResultStatus != eHAL_STATUS_SUCCESS) &&
+            (scanGetResultStatus != eHAL_STATUS_E_NULL_VALUE))
+        {
+            /*
+             * No scan results
+             * So, set the operation channel not selected
+             * to allow the default channel to be set when
+             * reporting to HDD
+             */
+            operChannel = SAP_CHANNEL_NOT_SELECTED;
+            VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                       FL("Get scan result failed! ret = %d"),
+                       scanGetResultStatus);
+        }
+        else
+        {
+#ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
+            if (scanID != 0)
+            {
+                VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH,
+                           "%s: Sending ACS Scan skip event", __func__);
+                sapSignalHDDevent(psapContext, NULL,
+                                  eSAP_ACS_SCAN_SUCCESS_EVENT,
+                                  (v_PVOID_t) eSAP_STATUS_SUCCESS);
+            }
+            else
+            {
+                VOS_TRACE(VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH,
+                          "%s: ACS scan id: %d (skipped ACS SCAN)",
+                          __func__, scanID);
+            }
+#endif
+            operChannel = sapSelectChannel(halHandle, psapContext, pResult);
+
+            sme_ScanResultPurge(halHandle, pResult);
+        }
+
+        if (operChannel == SAP_CHANNEL_NOT_SELECTED)
+#ifdef SOFTAP_CHANNEL_RANGE
+        {
+            VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO,
+                       FL("No suitable channel selected"));
+
+            if ( eCSR_BAND_ALL ==  psapContext->scanBandPreference ||
+                     psapContext->allBandScanned == eSAP_TRUE)
+            {
+                halStatus = sapSignalHDDevent(psapContext, NULL,
+                                      eSAP_ACS_CHANNEL_SELECTED,
+                                      (v_PVOID_t) eSAP_STATUS_FAILURE);
+            }
+            else
+            {
+                VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO,
+                           FL("Has scan band preference"));
+                if (eCSR_BAND_24 == psapContext->currentPreferredBand)
+                    psapContext->currentPreferredBand = eCSR_BAND_5G;
+                else
+                    psapContext->currentPreferredBand = eCSR_BAND_24;
+
+                psapContext->allBandScanned = eSAP_TRUE;
+                /*
+                 * Go back to scanning, scan next band
+                 *
+                 * 1. No need to pass the second parameter
+                 * as the SAP state machine is not started yet
+                 * and there is no need for any event posting.
+                 *
+                 * 2. Set third parameter to TRUE to indicate the
+                 * channel selection function to register a
+                 * different scan callback fucntion to process
+                 * the results pre start BSS.
+                 */
+                vosStatus = sapGotoChannelSel(psapContext, NULL, VOS_TRUE);
+                if (VOS_STATUS_SUCCESS == vosStatus)
+                {
+                    halStatus = eHAL_STATUS_SUCCESS;
+                }
+                return halStatus;
+            }
+        }
+#else
+        psapContext->channel = SAP_DEFAULT_24GHZ_CHANNEL;
+#endif
+        else
+        {
+            /*
+             * Valid Channel Found from scan results.
+             */
+            psapContext->channel = operChannel;
+        }
+
+        if (eHAL_STATUS_SUCCESS != ccmCfgGetInt(halHandle,
+                                             WNI_CFG_VHT_CHANNEL_WIDTH,
+                                             &vhtChannelWidth))
+        {
+            VOS_TRACE(VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                  FL("Get WNI_CFG_VHT_CHANNEL_WIDTH failed"));
+            /*
+             * In case of failure, take the vht channel width from
+             * original ini value
+             */
+            vhtChannelWidth = pMac->roam.configParam.nVhtChannelWidth;
+        }
+
+        sme_SelectCBMode(halHandle,
+          sapConvertSapPhyModeToCsrPhyMode(psapContext->csrRoamProfile.phyMode),
+          psapContext->channel, vhtChannelWidth);
+
+        /* determine secondary channel for 11n mode */
+        if ((eSAP_DOT11_MODE_11n == psapContext->csrRoamProfile.phyMode) ||
+            (eSAP_DOT11_MODE_11n_ONLY == psapContext->csrRoamProfile.phyMode)) {
+            ePhyChanBondState cbMode;
+
+            if (psapContext->channel > 14)
+                cbMode = pMac->roam.configParam.channelBondingMode5GHz;
+            else
+                cbMode = pMac->roam.configParam.channelBondingMode24GHz;
+
+            switch (cbMode) {
+            case PHY_DOUBLE_CHANNEL_LOW_PRIMARY:
+                psapContext->secondary_ch = psapContext->channel + 4;
+                break;
+            case PHY_DOUBLE_CHANNEL_HIGH_PRIMARY:
+                psapContext->secondary_ch = psapContext->channel - 4;
+                break;
+            case PHY_SINGLE_CHANNEL_CENTERED:
+            default:
+                psapContext->secondary_ch = 0;
+                break;
+            }
+
+            VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO,
+                           FL("psapContext->secondary_ch=%d"),
+                           psapContext->secondary_ch);
+        }
+
+#ifdef SOFTAP_CHANNEL_RANGE
+        if(psapContext->channelList != NULL)
+        {
+            /*
+             * Always free up the memory for
+             * channel selection whatever
+             * the result
+             */
+            vos_mem_free(psapContext->channelList);
+            psapContext->channelList = NULL;
+        }
+#endif
+
+        VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH,
+                   FL("Channel selected = %d"), psapContext->channel);
+
+        /*
+         * By now, Channel should be selected
+         * post a message to HDD to indicate
+         * the ACS channel selection complete.
+         */
+        halStatus = sapSignalHDDevent(psapContext, NULL,
+                                      eSAP_ACS_CHANNEL_SELECTED,
+                                      (v_PVOID_t) eSAP_STATUS_SUCCESS);
+    }
+    else
+    {
+        VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                   FL("CSR scanStatus = %s (%d), choose default channel"),
+                   "eCSR_SCAN_ABORT/FAILURE", scanStatus );
+#ifdef SOFTAP_CHANNEL_RANGE
+        /*
+         * if scan failed, select default channel in the
+         * BAND(2.4GHz/5GHZ)
+         */
+        ccmCfgGetInt( halHandle, WNI_CFG_SAP_CHANNEL_SELECT_OPERATING_BAND,
+                      &operatingBand);
+        if(eSAP_RF_SUBBAND_2_4_GHZ == operatingBand )
+            psapContext->channel = SAP_DEFAULT_24GHZ_CHANNEL;
+        else
+            psapContext->channel = SAP_DEFAULT_5GHZ_CHANNEL;
+#else
+        psapContext->channel = SAP_DEFAULT_24GHZ_CHANNEL;
+#endif
+        halStatus = sapSignalHDDevent(psapContext, NULL,
+                                      eSAP_ACS_CHANNEL_SELECTED,
+                                      (v_PVOID_t) eSAP_STATUS_SUCCESS);
+    }
+
+    if(eHAL_STATUS_SUCCESS != sme_CloseSession(halHandle,
+                                      psapContext->sessionId, NULL, NULL))
+    {
+        VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+            "In %s CloseSession error", __func__);
+    } else {
+        psapContext->isScanSessionOpen = eSAP_FALSE;
+    }
+    psapContext->sessionId = 0xff;
+
+    return halStatus;
+}
+
+/*==========================================================================
   FUNCTION    WLANSAP_RoamCallback()
 
   DESCRIPTION
diff --git a/CORE/SAP/src/sapChSelect.c b/CORE/SAP/src/sapChSelect.c
index f093bde15efd..7c3e8b5a0dd2 100644
--- a/CORE/SAP/src/sapChSelect.c
+++ b/CORE/SAP/src/sapChSelect.c
@@ -2334,11 +2334,14 @@ eChannelWidthInfo sapGetChannelWidthInfo(tHalHandle halHandle, ptSapContext pSap
 {
     v_U32_t cbMode;
     eChannelWidthInfo chWidth = CHWIDTH_HT20;
+    tpAniSirGlobal pMac = PMAC_STRUCT(halHandle);
 
-    if (eSAP_RF_SUBBAND_2_4_GHZ == operatingBand)
-        cbMode = sme_GetChannelBondingMode24G(halHandle);
-    else
-        cbMode = sme_GetChannelBondingMode5G(halHandle);
+    /* get cbMode based on if obss is enabled */
+    cbMode = (pMac->roam.configParam.obssEnabled) ? 1:0;
+
+    VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO,
+                  "%s: cbMode=%d, phyMode=%d",
+               __func__, cbMode, phyMode);
 
     if (phyMode == eSAP_DOT11_MODE_11n ||
         phyMode == eSAP_DOT11_MODE_11n_ONLY)
@@ -2639,34 +2642,44 @@ v_U8_t sapSelectChannel(tHalHandle halHandle, ptSapContext pSapCtx,  tScanResult
 #endif
 
     /* determine secondary channel for 2.4G channel 5, 6, 7 in HT40 */
-    if ((operatingBand == RF_SUBBAND_2_4_GHZ) && (chWidth == CHWIDTH_HT40) &&
-             (bestChNum >= 5) && (bestChNum <= 7)) {
-        int weight_below, weight_above, i;
+    if ((operatingBand == RF_SUBBAND_2_4_GHZ) && (chWidth == CHWIDTH_HT40)) {
         tSmeConfigParams *pSmeConfig;
-        tSapSpectChInfo *pSpectInfo;
-
-        weight_below = weight_above  = ACS_WEIGHT_MAX;
-        pSpectInfo = pSpectInfoParams->pSpectCh;
-
-        for (i = 0; i < pSpectInfoParams->numSpectChans ; i++) {
-            if (pSpectInfo[i].chNum == (bestChNum - 4))
-                weight_below = pSpectInfo[i].weight;
-
-            if (pSpectInfo[i].chNum == (bestChNum + 4))
-                weight_above = pSpectInfo[i].weight;
-        }
-
         pSmeConfig = vos_mem_malloc(sizeof(*pSmeConfig));
         if (NULL != pSmeConfig) {
             sme_GetConfigParam(halHandle, pSmeConfig);
 
-            if (weight_below < weight_above)
-                pSmeConfig->csrConfig.channelBondingMode24GHz =
-                       eCSR_INI_DOUBLE_CHANNEL_HIGH_PRIMARY;
-            else
-                pSmeConfig->csrConfig.channelBondingMode24GHz =
-                       eCSR_INI_DOUBLE_CHANNEL_LOW_PRIMARY;
+            if ((bestChNum >= 5) && (bestChNum <= 7)) {
+                int weight_below, weight_above, i;
+                tSapSpectChInfo *pSpectInfo;
+
+                weight_below = weight_above  = ACS_WEIGHT_MAX;
+                pSpectInfo = pSpectInfoParams->pSpectCh;
+
+                for (i = 0; i < pSpectInfoParams->numSpectChans ; i++) {
+                    if (pSpectInfo[i].chNum == (bestChNum - 4))
+                        weight_below = pSpectInfo[i].weight;
 
+                    if (pSpectInfo[i].chNum == (bestChNum + 4))
+                        weight_above = pSpectInfo[i].weight;
+                }
+
+                if (weight_below < weight_above)
+                    pSmeConfig->csrConfig.channelBondingMode24GHz =
+                           eCSR_INI_DOUBLE_CHANNEL_HIGH_PRIMARY;
+                else
+                    pSmeConfig->csrConfig.channelBondingMode24GHz =
+                           eCSR_INI_DOUBLE_CHANNEL_LOW_PRIMARY;
+            } else {
+                if (bestChNum >= 1 && bestChNum <= 5)
+                   pSmeConfig->csrConfig.channelBondingMode24GHz =
+                    eCSR_INI_DOUBLE_CHANNEL_LOW_PRIMARY;
+                else if (bestChNum >= 6 && bestChNum <= 13)
+                   pSmeConfig->csrConfig.channelBondingMode24GHz =
+                    eCSR_INI_DOUBLE_CHANNEL_HIGH_PRIMARY;
+                else if (bestChNum ==14)
+                    pSmeConfig->csrConfig.channelBondingMode24GHz =
+                    eCSR_INI_SINGLE_CHANNEL_CENTERED;
+            }
             sme_UpdateConfig(halHandle, pSmeConfig);
             vos_mem_free(pSmeConfig);
         }
diff --git a/CORE/SAP/src/sapFsm.c b/CORE/SAP/src/sapFsm.c
index 2b5ba202010c..4b53d07082aa 100644
--- a/CORE/SAP/src/sapFsm.c
+++ b/CORE/SAP/src/sapFsm.c
@@ -1986,6 +1986,8 @@ sapDfsIsChannelInNolList(ptSapContext sapContext, v_U8_t channelNumber,
     IN
     sapContext  : Sap Context value
     sapEvent    : State machine event
+    sapDoAcsPreStartBss: VOS_TRUE, if ACS scan is issued pre start BSS.
+                         VOS_FALSE, if ACS scan is issued post start BSS.
 
   RETURN VALUE
     The VOS_STATUS code associated with performing the operation
@@ -1998,7 +2000,8 @@ VOS_STATUS
 sapGotoChannelSel
 (
     ptSapContext sapContext,
-    ptWLAN_SAPEvent sapEvent
+    ptWLAN_SAPEvent sapEvent,
+    v_BOOL_t sapDoAcsPreStartBss
 )
 {
     /* Initiate a SCAN request */
@@ -2140,17 +2143,38 @@ sapGotoChannelSel
 #ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
                 }
 #endif
-                halStatus = sme_ScanRequest(hHal,
-                            sapContext->sessionId,
-                            &scanRequest,
-                            /*, when ID == 0 11D scan/active scan with callback,
-                             * min-maxChntime set in csrScanRequest()?
-                             */
-                            &scanRequestID,
-                            /*csrScanCompleteCallback callback,*/
-                            &WLANSAP_ScanCallback,
-                            /* pContext scanRequestID filled up*/
-                            sapContext);
+
+                if (VOS_TRUE == sapDoAcsPreStartBss)
+                {
+                    halStatus = sme_ScanRequest(hHal,
+                                    sapContext->sessionId,
+                                    &scanRequest,
+                                    /* when ID == 0 11D scan/active
+                                     * scan with callback,
+                                     * min-maxChntime set in csrScanRequest()?
+                                     */
+                                    &scanRequestID,
+                                    /*csrScanCompleteCallback callback,*/
+                                    &WLANSAP_PreStartBssAcsScanCallback,
+                                    /* pContext scanRequestID filled up*/
+                                    sapContext);
+
+                }
+                else
+                {
+                    halStatus = sme_ScanRequest(hHal,
+                                    sapContext->sessionId,
+                                    &scanRequest,
+                                    /* when ID == 0 11D scan/active
+                                     * scan with callback,
+                                     * min-maxChntime set in csrScanRequest()?
+                                     */
+                                    &scanRequestID,
+                                    /*csrScanCompleteCallback callback,*/
+                                    &WLANSAP_ScanCallback,
+                                    /* pContext scanRequestID filled up*/
+                                    sapContext);
+                }
                 if (eHAL_STATUS_SUCCESS != halStatus)
                 {
                     VOS_TRACE(VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
@@ -2169,10 +2193,22 @@ sapGotoChannelSel
                         sapContext->channelList = NULL;
                     }
 #endif
-                    /* Fill in the event structure */
-                    sapEventInit(sapEvent);
-                    /* Handle event */
-                    vosStatus = sapFsm(sapContext, sapEvent);
+                    if (VOS_TRUE == sapDoAcsPreStartBss)
+                    {
+                        /*
+                         * In case of ACS req before start Bss,
+                         * return failure so that the calling
+                         * fucntion can use the default channel.
+                         */
+                        return VOS_STATUS_E_FAILURE;
+                    }
+                    else
+                    {
+                        /* Fill in the event structure */
+                        sapEventInit(sapEvent);
+                        /* Handle event */
+                        vosStatus = sapFsm(sapContext, sapEvent);
+                    }
                 }
                 else
                 {
@@ -2188,8 +2224,20 @@ sapGotoChannelSel
         if (sapContext->skip_acs_scan_status == eSAP_SKIP_ACS_SCAN) {
             VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
                    "## %s SKIPPED ACS SCAN", __func__);
-            WLANSAP_ScanCallback(hHal, sapContext, sapContext->sessionId, 0,
-                eCSR_SCAN_SUCCESS);
+            if (VOS_TRUE == sapDoAcsPreStartBss)
+            {
+                WLANSAP_PreStartBssAcsScanCallback(hHal, sapContext,
+                                                   sapContext->sessionId,
+                                                   0,
+                                                   eCSR_SCAN_SUCCESS);
+            }
+            else
+            {
+                WLANSAP_ScanCallback(hHal, sapContext,
+                                     sapContext->sessionId,
+                                     0,
+                                     eCSR_SCAN_SUCCESS);
+            }
          }
 #endif
     }
@@ -2198,11 +2246,22 @@ sapGotoChannelSel
         VOS_TRACE(VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH,
                   "In %s, for configured channel, Ch= %d",
                   __func__, sapContext->channel);
-        /* Fill in the event structure */
-        // Eventhough scan was not done, means a user set channel was chosen
-        sapEventInit(sapEvent);
-        /* Handle event */
-        vosStatus = sapFsm(sapContext, sapEvent);
+        if (VOS_TRUE == sapDoAcsPreStartBss)
+        {
+            VOS_TRACE(VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                      "In %s, ACS Disabled, Configured Ch= %d",
+                      __func__, sapContext->channel);
+
+            return VOS_STATUS_E_FAILURE;
+        }
+        else
+        {
+            /* Fill in the event structure */
+            // Eventhough scan was not done, means a user set channel was chosen
+            sapEventInit(sapEvent);
+            /* Handle event */
+            vosStatus = sapFsm(sapContext, sapEvent);
+        }
     }
 
     /* If scan failed, get default channel and advance state machine as success with default channel */
@@ -2567,6 +2626,22 @@ sapSignalHDDevent
                                                         (eSapStatus )context;
             break;
 
+        case eSAP_ACS_CHANNEL_SELECTED:
+            sapApAppEvent.sapHddEventCode = sapHddevent;
+            if ( eSAP_STATUS_SUCCESS == (eSapStatus )context)
+            {
+                sapApAppEvent.sapevt.sapAcsChSelected.pri_channel =
+                                                      sapContext->channel;
+                sapApAppEvent.sapevt.sapAcsChSelected.sec_channel =
+                                                      sapContext->secondary_ch;
+            }
+            else if (eSAP_STATUS_FAILURE == (eSapStatus )context)
+            {
+                sapApAppEvent.sapevt.sapAcsChSelected.pri_channel = 0;
+                sapApAppEvent.sapevt.sapAcsChSelected.sec_channel = 0;
+            }
+            break;
+
         case eSAP_STOP_BSS_EVENT:
             VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH, "In %s, SAP event callback event = %s",
                        __func__, "eSAP_STOP_BSS_EVENT");
@@ -3198,8 +3273,12 @@ sapFsm
                 /* Set SAP device role */
                 sapContext->sapsMachine = eSAP_CH_SELECT;
 
-                /* Perform sme_ScanRequest */
-                vosStatus = sapGotoChannelSel(sapContext, sapEvent);
+                /*
+                 * Perform sme_ScanRequest
+                 * This scan request is post start bss
+                 * request so, set the third to false.
+                 */
+                vosStatus = sapGotoChannelSel(sapContext, sapEvent, VOS_FALSE);
 
                 /* Transition from eSAP_DISCONNECTED to eSAP_CH_SELECT (both without substates) */
                 VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH, "In %s, from state %s => %s",
@@ -3229,8 +3308,12 @@ sapFsm
                  /* Set SAP device role */
                 sapContext->sapsMachine = eSAP_CH_SELECT;
 
-                /* Perform sme_ScanRequest */
-                vosStatus = sapGotoChannelSel(sapContext, sapEvent);
+                /*
+                 * Perform sme_ScanRequest
+                 * This scan request is post start bss
+                 * request so, set the third to false.
+                 */
+                vosStatus = sapGotoChannelSel(sapContext, sapEvent, VOS_FALSE);
             }
             else
             {
diff --git a/CORE/SAP/src/sapInternal.h b/CORE/SAP/src/sapInternal.h
index 1905f78075d6..ed60927bcaec 100644
--- a/CORE/SAP/src/sapInternal.h
+++ b/CORE/SAP/src/sapInternal.h
@@ -165,6 +165,7 @@ typedef struct sSapContext {
 
     // Include the current channel of AP
     v_U32_t             channel;
+    v_U32_t             secondary_ch;
 
     // Include the SME(CSR) sessionId here
     v_U8_t              sessionId;
@@ -335,6 +336,43 @@ WLANSAP_ScanCallback
 
 /*==========================================================================
 
+  FUNCTION    WLANSAP_PreStartBssAcsScanCallback()
+
+  DESCRIPTION
+    Callback for Scan (scan results) Events
+
+  DEPENDENCIES
+    NA.
+
+  PARAMETERS
+
+    IN
+    tHalHandle:  the tHalHandle passed in with the scan request
+    *p2: the second context pass in for the caller, opaque sap Handle here
+    scanID:
+    sessionId: Session identifier
+    status: Status of scan -success, failure or abort
+
+  RETURN VALUE
+    The eHalStatus code associated with performing the operation
+
+    eHAL_STATUS_SUCCESS:  Success
+
+  SIDE EFFECTS
+
+============================================================================*/
+eHalStatus
+WLANSAP_PreStartBssAcsScanCallback
+(
+  tHalHandle halHandle,
+  void *pContext,
+  v_U8_t sessionId,
+  v_U32_t scanID,
+  eCsrScanStatus scanStatus
+);
+
+/*==========================================================================
+
   FUNCTION    WLANSAP_RoamCallback()
 
   DESCRIPTION
@@ -545,6 +583,38 @@ sapFsm
 );
 
 /*==========================================================================
+  FUNCTION    sapGotoChannelSel
+
+  DESCRIPTION
+    Function for initiating scan request for SME
+
+  DEPENDENCIES
+    NA.
+
+  PARAMETERS
+
+    IN
+    sapContext  : Sap Context value
+    sapEvent    : State machine event/ NULL if no FSM event is required.
+    sapDoAcsPreStartBss: VOS_TRUE, if ACS scan is issued pre start BSS.
+                         VOS_FALSE, if ACS scan is issued post start BSS.
+
+  RETURN VALUE
+    The VOS_STATUS code associated with performing the operation
+
+    VOS_STATUS_SUCCESS: Success
+
+  SIDE EFFECTS
+============================================================================*/
+VOS_STATUS
+sapGotoChannelSel
+(
+    ptSapContext sapContext,
+    ptWLAN_SAPEvent sapEvent,
+    v_BOOL_t sapDoAcsPreStartBss
+);
+
+/*==========================================================================
 
   FUNCTION    sapConvertToCsrProfile
 
diff --git a/CORE/SAP/src/sapModule.c b/CORE/SAP/src/sapModule.c
index bce11240f346..5ca1f3001403 100644
--- a/CORE/SAP/src/sapModule.c
+++ b/CORE/SAP/src/sapModule.c
@@ -601,6 +601,131 @@ v_U16_t WLANSAP_CheckCCIntf(v_PVOID_t Ctx)
     return intf_ch;
 }
 #endif
+
+/*==========================================================================
+  FUNCTION    WLANSAP_SetScanAcsChannelParams
+
+  DESCRIPTION
+    This api function is used to copy Scan and Channel parameters from sap
+    config to sap context.
+
+  DEPENDENCIES
+
+  PARAMETERS
+
+    IN
+    pConfig    : Pointer to the SAP config
+    sapContext : Pointer to the SAP Context.
+    pUsrContext: Parameter that will be passed
+                 back in all the SAP callback events.
+
+  RETURN VALUE
+    The result code associated with performing the operation
+
+    VOS_STATUS_E_FAULT: Pointer to SAP cb is NULL ; access would cause a page
+                        fault
+    VOS_STATUS_SUCCESS: Success
+
+  SIDE EFFECTS
+============================================================================*/
+VOS_STATUS
+WLANSAP_SetScanAcsChannelParams(tsap_Config_t *pConfig,
+                                ptSapContext pSapCtx,
+                                v_PVOID_t  pUsrContext)
+{
+    tHalHandle hHal = NULL;
+    tANI_BOOLEAN restartNeeded;
+    int ret;
+
+    if (NULL == pConfig)
+    {
+        VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                   "%s: Invalid pConfig passed ", __func__);
+        return VOS_STATUS_E_FAULT;
+    }
+
+    if (NULL == pSapCtx)
+    {
+        VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                   "%s: Invalid pConfig passed ", __func__);
+        return VOS_STATUS_E_FAULT;
+    }
+
+    /* Channel selection is auto or configured */
+    pSapCtx->channel = pConfig->channel;
+#ifdef FEATURE_WLAN_MCC_TO_SCC_SWITCH
+    pSapCtx->cc_switch_mode = pConfig->cc_switch_mode;
+#endif
+    pSapCtx->scanBandPreference = pConfig->scanBandPreference;
+    pSapCtx->acsBandSwitchThreshold = pConfig->acsBandSwitchThreshold;
+    pSapCtx->pUsrContext = pUsrContext;
+    pSapCtx->apAutoChannelSelection = pConfig->apAutoChannelSelection;
+    pSapCtx->apStartChannelNum = pConfig->apStartChannelNum;
+    pSapCtx->apEndChannelNum = pConfig->apEndChannelNum;
+#ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
+    pSapCtx->skip_acs_scan_status = pConfig->skip_acs_scan_status;
+    pSapCtx->skip_acs_scan_range1_endch = pConfig->skip_acs_scan_range1_endch;
+    pSapCtx->skip_acs_scan_range1_stch = pConfig->skip_acs_scan_range1_stch;
+    pSapCtx->skip_acs_scan_range2_endch = pConfig->skip_acs_scan_range2_endch;
+    pSapCtx->skip_acs_scan_range2_stch = pConfig->skip_acs_scan_range2_stch;
+#endif
+    pSapCtx->enableOverLapCh = pConfig->enOverLapCh;
+    if (strlen(pConfig->acsAllowedChnls) > 0)
+    {
+#ifdef WLAN_FEATURE_MBSSID
+        ret = sapSetPreferredChannel(pSapCtx, pConfig->acsAllowedChnls);
+#else
+        ret = sapSetPreferredChannel(pConfig->acsAllowedChnls);
+#endif
+        if (0 != ret)
+        {
+            VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH,
+                       "%s: ACS set preferred channel failed!", __func__);
+            return VOS_STATUS_E_FAULT;
+        }
+    }
+    /*
+     * Set the BSSID to your "self MAC Addr" read
+     * the mac address from Configuation ITEM received
+     * from HDD
+     */
+    pSapCtx->csrRoamProfile.BSSIDs.numOfBSSIDs = 1;
+    vos_mem_copy(pSapCtx->csrRoamProfile.BSSIDs.bssid,
+                 pSapCtx->self_mac_addr,
+                 sizeof( tCsrBssid ));
+
+    /*
+     * Save a copy to SAP context
+     */
+    vos_mem_copy(pSapCtx->csrRoamProfile.BSSIDs.bssid,
+                 pConfig->self_macaddr.bytes, sizeof(v_MACADDR_t));
+    vos_mem_copy(pSapCtx->self_mac_addr,
+                 pConfig->self_macaddr.bytes, sizeof(v_MACADDR_t));
+
+    hHal = (tHalHandle)VOS_GET_HAL_CB(pSapCtx->pvosGCtx);
+    if (NULL == hHal)
+    {
+        VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH,
+                   "%s: Invalid MAC context from pvosGCtx", __func__);
+    }
+    else
+    {
+        //If concurrent session is running that is already associated
+        //then we just follow that sessions country info (whether
+        //present or not doesn't maater as we have to follow whatever
+        //STA session does)
+        if ((0 == sme_GetConcurrentOperationChannel(hHal)) &&
+             pConfig->ieee80211d)
+        {
+            /* Setting the region/country  information */
+            sme_setRegInfo(hHal, pConfig->countryCode);
+            sme_ResetCountryCodeInformation(hHal, &restartNeeded);
+        }
+    }
+
+    return VOS_STATUS_SUCCESS;
+}
+
 /*==========================================================================
   FUNCTION    WLANSAP_StartBss
 
@@ -3762,3 +3887,160 @@ void WLANSAP_PopulateDelStaParams(const v_U8_t *mac,
                    pDelStaParams->reason_code, pDelStaParams->subtype,
                    MAC_ADDR_ARRAY(pDelStaParams->peerMacAddr));
 }
+
+/*==========================================================================
+  FUNCTION    WLANSAP_ACS_CHSelect
+
+  DESCRIPTION
+    This api function provides ACS selection for BSS
+
+  DEPENDENCIES
+    NA.
+
+  PARAMETERS
+
+    IN
+      pvosGCtx: Pointer to vos global context structure
+      pConfig: Pointer to configuration structure passed down from HDD
+      pACSEventCallback: Callback function in HDD called by SAP to inform
+                         HDD about channel section result
+      usrDataForCallback: Parameter that will be passed back in all the
+                          SAP callback events.
+
+  RETURN VALUE
+    The VOS_STATUS code associated with performing the operation
+
+    VOS_STATUS_SUCCESS:  Success
+
+  SIDE EFFECTS
+============================================================================*/
+VOS_STATUS
+WLANSAP_ACS_CHSelect(v_PVOID_t pvosGCtx,
+                     tpWLAN_SAPEventCB pACSEventCallback,
+                     tsap_Config_t *pConfig,
+                     v_PVOID_t  pUsrContext)
+{
+    ptSapContext sapContext = NULL;
+    tHalHandle hHal = NULL;
+    VOS_STATUS vosStatus = VOS_STATUS_E_FAILURE;
+    eHalStatus halStatus = eHAL_STATUS_FAILURE;
+    tpAniSirGlobal pMac = NULL;
+
+    sapContext = VOS_GET_SAP_CB( pvosGCtx );
+    if (NULL == sapContext) {
+        VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                   "%s: Invalid SAP pointer from pvosGCtx", __func__);
+
+        return VOS_STATUS_E_FAULT;
+    }
+
+    hHal = (tHalHandle)VOS_GET_HAL_CB(sapContext->pvosGCtx);
+    if (NULL == hHal) {
+        VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                   "%s: Invalid MAC context from pvosGCtx", __func__);
+        return VOS_STATUS_E_FAULT;
+    }
+
+    if (sapContext->isSapSessionOpen == eSAP_TRUE) {
+        VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_FATAL,
+                   "%s:SME Session is already opened\n",__func__);
+        return VOS_STATUS_E_EXISTS;
+    }
+
+    sapContext->sessionId = 0xff;
+
+    pMac = PMAC_STRUCT( hHal );
+    if ((!pMac->roam.configParam.obssEnabled) &&
+        ((pMac->roam.configParam.phyMode == eCSR_DOT11_MODE_abg) ||
+         (pMac->roam.configParam.phyMode == eCSR_DOT11_MODE_11a) ||
+         (pMac->roam.configParam.phyMode == eCSR_DOT11_MODE_11g)))
+       sapContext->csrRoamProfile.phyMode = eSAP_DOT11_MODE_abg;
+    else
+       sapContext->csrRoamProfile.phyMode = eSAP_DOT11_MODE_11n;
+
+    if ((pConfig->channel == AUTO_CHANNEL_SELECT) &&
+        (sapContext->isScanSessionOpen == eSAP_FALSE)) {
+        tANI_U32 type, subType;
+
+        if(VOS_STATUS_SUCCESS ==
+                      vos_get_vdev_types(VOS_STA_MODE, &type, &subType)) {
+            /*
+             * Open SME Session for scan
+             */
+            if(eHAL_STATUS_SUCCESS  != sme_OpenSession(hHal, NULL, sapContext,
+                                                   sapContext->self_mac_addr,
+                                                   &sapContext->sessionId,
+                                                   type, subType)) {
+                VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                           "Error: In %s calling sme_OpenSession", __func__);
+                return VOS_STATUS_E_FAILURE;
+            }
+            else
+                sapContext->isScanSessionOpen = eSAP_TRUE;
+        }
+
+        /*
+         * Copy the HDD callback function to report the
+         * ACS result after scan in SAP context callback function.
+         */
+        sapContext->pfnSapEventCallback = pACSEventCallback;
+        /*
+         * init dfs channel nol
+         */
+        sapInitDfsChannelNolList(sapContext);
+
+        /*
+         * Now, configure the scan and ACS channel params
+         * to issue a scan request.
+         */
+        WLANSAP_SetScanAcsChannelParams(pConfig, sapContext, pUsrContext);
+
+        /*
+         * Issue the scan request. This scan request is
+         * issued before the start BSS is done so
+         *
+         * 1. No need to pass the second parameter
+         * as the SAP state machine is not started yet
+         * and there is no need for any event posting.
+         *
+         * 2. Set third parameter to TRUE to indicate the
+         * channel selection function to register a
+         * different scan callback fucntion to process
+         * the results pre start BSS.
+         */
+        vosStatus = sapGotoChannelSel(sapContext, NULL, VOS_TRUE);
+
+        if (VOS_STATUS_E_ABORTED == vosStatus) {
+            VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                       "In %s,DFS not supported in the current operating mode",
+                        __func__);
+            return VOS_STATUS_E_FAILURE;
+        }
+        else if (VOS_STATUS_E_CANCELED == vosStatus) {
+             /*
+              * ERROR is returned when either the SME scan request
+              * failed or ACS is not enabled. So, default channel
+              * is selected and this default channel should be sent
+              * to the HDD.
+              */
+             VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                 FL("Scan Req Failed/ACS not enabled,default channel = %d"),
+                 sapContext->channel);
+             halStatus = sapSignalHDDevent(sapContext, NULL,
+                                           eSAP_ACS_CHANNEL_SELECTED,
+                                           (v_PVOID_t) eSAP_STATUS_SUCCESS);
+
+             if (eHAL_STATUS_SUCCESS == halStatus) {
+                 vosStatus = VOS_STATUS_SUCCESS;
+                 return vosStatus;
+             }
+             VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_ERROR,
+                        FL("Failed to post eSAP_ACS_CHANNEL_SELECTED to HDD"));
+             return VOS_STATUS_E_FAILURE;
+        }
+        else if (VOS_STATUS_SUCCESS == vosStatus)
+            VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH,
+                       FL("Successfully Issued a Pre Start Bss Scan Request"));
+    }
+    return vosStatus;
+}
diff --git a/CORE/SME/src/sme_common/sme_Api.c b/CORE/SME/src/sme_common/sme_Api.c
index 8f96b1de6939..3d748344dc90 100644
--- a/CORE/SME/src/sme_common/sme_Api.c
+++ b/CORE/SME/src/sme_common/sme_Api.c
@@ -11829,23 +11829,18 @@ VOS_STATUS sme_SelectCBMode(tHalHandle hHal, eCsrPhyMode eCsrPhyMode,
           }
       }
 
-#ifdef QCA_HT_2040_COEX
-      /* if obss is enabled, the channel bonding mode is coming from hostapd,
-         so we don't need to hard code it here  */
-      if (!pMac->roam.configParam.obssEnabled)
-#endif
-          if (pMac->roam.configParam.channelBondingMode24GHz)
-          {
-              if (channel >= 1 && channel <= 5)
-                 smeConfig.csrConfig.channelBondingMode24GHz =
-                  eCSR_INI_DOUBLE_CHANNEL_LOW_PRIMARY;
-              else if (channel >= 6 && channel <= 13)
-                 smeConfig.csrConfig.channelBondingMode24GHz =
-                  eCSR_INI_DOUBLE_CHANNEL_HIGH_PRIMARY;
-              else if (channel ==14)
-                 smeConfig.csrConfig.channelBondingMode24GHz =
-                  eCSR_INI_SINGLE_CHANNEL_CENTERED;
-          }
+      if (pMac->roam.configParam.channelBondingMode24GHz)
+      {
+          if (channel >= 1 && channel <= 5)
+             smeConfig.csrConfig.channelBondingMode24GHz =
+              eCSR_INI_DOUBLE_CHANNEL_LOW_PRIMARY;
+          else if (channel >= 6 && channel <= 13)
+             smeConfig.csrConfig.channelBondingMode24GHz =
+              eCSR_INI_DOUBLE_CHANNEL_HIGH_PRIMARY;
+          else if (channel ==14)
+             smeConfig.csrConfig.channelBondingMode24GHz =
+              eCSR_INI_SINGLE_CHANNEL_CENTERED;
+      }
    }
 
    /*