qcacld-2.0: On demand OBSS scan of SAP

To shorten the SAP starting time, the OBSS scan
can be skipped if the ACS scan is performed
and the ACS scan channels cover the OBSS scan
channel list.

This change caches the ACS channel list and
skip the OBSS scan if necessary.

Change-Id: Iae54115051ae037c83b8dd2b639754f941c1d0f5
CRs-Fixed: 1073053

9 files changed, 245 insertions, 34 deletions

diff --git a/CORE/HDD/inc/wlan_hdd_cfg80211.h b/CORE/HDD/inc/wlan_hdd_cfg80211.h
index b68ab6da55db..329f8bb09ca4 100644
--- a/CORE/HDD/inc/wlan_hdd_cfg80211.h
+++ b/CORE/HDD/inc/wlan_hdd_cfg80211.h
@@ -2025,6 +2025,9 @@ struct cfg80211_bss* wlan_hdd_cfg80211_update_bss_db( hdd_adapter_t *pAdapter,
                                       tCsrRoamInfo *pRoamInfo
                                       );
 
+int wlan_hdd_cfg80211_update_bss(struct wiphy *wiphy,
+			hdd_adapter_t *pAdapter);
+
 #ifdef FEATURE_WLAN_LFR
 int wlan_hdd_cfg80211_pmksa_candidate_notify(
                     hdd_adapter_t *pAdapter, tCsrRoamInfo *pRoamInfo,
diff --git a/CORE/HDD/inc/wlan_hdd_main.h b/CORE/HDD/inc/wlan_hdd_main.h
index de9ca053f13a..d79201fc1ade 100644
--- a/CORE/HDD/inc/wlan_hdd_main.h
+++ b/CORE/HDD/inc/wlan_hdd_main.h
@@ -1775,6 +1775,9 @@ struct hdd_context_s
 #ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
     vos_timer_t skip_acs_scan_timer;
     v_U8_t skip_acs_scan_status;
+    uint8_t *last_acs_channel_list;
+    uint8_t num_of_channels;
+    spinlock_t acs_skip_lock;
 #endif
 
     vos_wake_lock_t sap_dfs_wakelock;
diff --git a/CORE/HDD/src/wlan_hdd_cfg80211.c b/CORE/HDD/src/wlan_hdd_cfg80211.c
index e9847797d3c4..016b2671fd81 100644
--- a/CORE/HDD/src/wlan_hdd_cfg80211.c
+++ b/CORE/HDD/src/wlan_hdd_cfg80211.c
@@ -17093,12 +17093,17 @@ wlan_hdd_cfg80211_update_bss_db(hdd_adapter_t *pAdapter,
     return bss;
 }
 
-/*
- * FUNCTION: wlan_hdd_cfg80211_update_bss
+/**
+ * wlan_hdd_cfg80211_update_bss() - update scan result to cfg80211
+ * @wiphy: wiphy context
+ * @pAdapter: hdd_adapter_t context
+ *
+ * This function will update the cached scan result to cfg80211 module
+ *
+ * Return: 0 for updating successfully
+ *            other value for error
  */
-static int wlan_hdd_cfg80211_update_bss( struct wiphy *wiphy,
-                                         hdd_adapter_t *pAdapter
-                                        )
+int wlan_hdd_cfg80211_update_bss(struct wiphy *wiphy, hdd_adapter_t *pAdapter)
 {
     tHalHandle hHal = WLAN_HDD_GET_HAL_CTX(pAdapter);
     tCsrScanResultInfo *pScanResult;
@@ -17688,6 +17693,66 @@ bool hdd_isConnectionInProgress(hdd_context_t *pHddCtx)
 	return false;
 }
 
+#ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
+/**
+ * wlan_hdd_sap_skip_scan_check() - The function will check OBSS
+ *         scan skip or not for SAP.
+ * @hdd_ctx: pointer to hdd context.
+ * @request: pointer to scan request.
+ *
+ * This function will check the scan request's chan list against the
+ * previous ACS scan chan list. If all the chan are covered by
+ * previous ACS scan, we can skip the scan and return scan complete
+ * to save the SAP starting time.
+ *
+ * Return: true to skip the scan,
+ *            false to continue the scan
+ */
+static bool wlan_hdd_sap_skip_scan_check(hdd_context_t *hdd_ctx,
+	struct cfg80211_scan_request *request)
+{
+	int i, j;
+	bool skip;
+
+	hddLog(LOG1, FL("HDD_ACS_SKIP_STATUS = %d"),
+		hdd_ctx->skip_acs_scan_status);
+	if (hdd_ctx->skip_acs_scan_status != eSAP_SKIP_ACS_SCAN)
+		return false;
+	spin_lock(&hdd_ctx->acs_skip_lock);
+	if (hdd_ctx->last_acs_channel_list == NULL ||
+	   hdd_ctx->num_of_channels == 0 ||
+	   request->n_channels == 0) {
+		spin_unlock(&hdd_ctx->acs_skip_lock);
+		return false;
+	}
+	skip = true;
+	for (i = 0; i < request->n_channels ; i++ ) {
+		bool find = false;
+		for (j = 0; j < hdd_ctx->num_of_channels; j++) {
+			if (hdd_ctx->last_acs_channel_list[j] ==
+			   request->channels[i]->hw_value) {
+				find = true;
+				break;
+			}
+		}
+		if (!find) {
+			skip = false;
+			hddLog(LOG1, FL("Chan %d isn't in ACS chan list"),
+				request->channels[i]->hw_value);
+			break;
+		}
+	}
+	spin_unlock(&hdd_ctx->acs_skip_lock);
+	return skip;
+}
+#else
+static bool wlan_hdd_sap_skip_scan_check(hdd_context_t *hdd_ctx,
+	struct cfg80211_scan_request *request)
+{
+	return false;
+}
+#endif
+
 static void wlan_hdd_cfg80211_scan_block_cb(struct work_struct *work)
 {
     hdd_adapter_t *adapter = container_of(work,
@@ -17779,6 +17844,9 @@ int __wlan_hdd_cfg80211_scan( struct wiphy *wiphy,
              * Thus we return null scan result. If we return scan failure
              * hostapd fails secondary AP startup.
              */
+            hddLog(LOGE,
+                   FL("##In DFS Master mode. Scan aborted"));
+
             pAdapter->request = request;
 
             vos_init_work(&pAdapter->scan_block_work,
@@ -17852,6 +17920,16 @@ int __wlan_hdd_cfg80211_scan( struct wiphy *wiphy,
         hddLog(LOGE, FL("Scan not allowed"));
         return -EBUSY;
     }
+    /* Check whether SAP scan can be skipped or not */
+    if (pAdapter->device_mode == WLAN_HDD_SOFTAP &&
+       wlan_hdd_sap_skip_scan_check(pHddCtx, request)) {
+        hddLog(LOGE, FL("sap scan skipped"));
+        pAdapter->request = request;
+        vos_init_work(&pAdapter->scan_block_work,
+                  wlan_hdd_cfg80211_scan_block_cb);
+        schedule_work(&pAdapter->scan_block_work);
+        return 0;
+    }
 
     vos_mem_zero( &scanRequest, sizeof(scanRequest));
 
diff --git a/CORE/HDD/src/wlan_hdd_hostapd.c b/CORE/HDD/src/wlan_hdd_hostapd.c
index 67791575975f..3ab859ebb1f1 100644
--- a/CORE/HDD/src/wlan_hdd_hostapd.c
+++ b/CORE/HDD/src/wlan_hdd_hostapd.c
@@ -1286,6 +1286,78 @@ static VOS_STATUS hdd_wlan_set_dfs_nol(const void *pdfs_list, u16 sdfs_list)
 }
 #endif
 
+#ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
+/**
+ * hdd_handle_acs_scan_event() - handle acs scan event for SAP
+ * @sap_event: tpSap_Event
+ * @adapter: hdd_adapter_t for SAP
+ *
+ * The function is to handle the eSAP_ACS_SCAN_SUCCESS_EVENT event.
+ * It will update scan result to cfg80211 and start a timer to flush the
+ * cached acs scan result.
+ *
+ * Return: VOS_STATUS_SUCCESS on success,
+          other value on failure
+ */
+static VOS_STATUS hdd_handle_acs_scan_event(tpSap_Event sap_event,
+		hdd_adapter_t *adapter)
+{
+	hdd_context_t *hdd_ctx;
+	struct tsap_acs_scan_complete_event *comp_evt;
+	VOS_STATUS vos_status;
+	int chan_list_size;
+
+	hdd_ctx = (hdd_context_t*)(adapter->pHddCtx);
+	if (!hdd_ctx) {
+		hddLog(VOS_TRACE_LEVEL_ERROR, FL("HDD context is null"));
+		return VOS_STATUS_E_FAILURE;
+	}
+	comp_evt = &sap_event->sapevt.sap_acs_scan_comp;
+	hdd_ctx->skip_acs_scan_status = eSAP_SKIP_ACS_SCAN;
+	spin_lock(&hdd_ctx->acs_skip_lock);
+	vos_mem_free(hdd_ctx->last_acs_channel_list);
+	hdd_ctx->last_acs_channel_list = NULL;
+	hdd_ctx->num_of_channels = 0;
+	/* cache the previous ACS scan channel list .
+	 * If the following OBSS scan chan list is covered by ACS chan list,
+	 * we can skip OBSS Scan to save SAP starting total time.
+	 */
+	if (comp_evt->num_of_channels && comp_evt->channellist) {
+		chan_list_size = comp_evt->num_of_channels *
+			sizeof(comp_evt->channellist[0]);
+		hdd_ctx->last_acs_channel_list = vos_mem_malloc(
+			chan_list_size);
+		if (hdd_ctx->last_acs_channel_list) {
+			vos_mem_copy(hdd_ctx->last_acs_channel_list,
+				comp_evt->channellist,
+				chan_list_size);
+			hdd_ctx->num_of_channels = comp_evt->num_of_channels;
+		}
+	}
+	spin_unlock(&hdd_ctx->acs_skip_lock);
+	/* Update ACS scan result to cfg80211. Then OBSS scan can reuse the
+	 * scan result.
+	 */
+	if (wlan_hdd_cfg80211_update_bss(hdd_ctx->wiphy, adapter))
+		hddLog(VOS_TRACE_LEVEL_INFO, FL("NO SCAN result"));
+
+	hddLog(LOG1, FL("Reusing Last ACS scan result for %d sec"),
+		ACS_SCAN_EXPIRY_TIMEOUT_S);
+	vos_timer_stop( &hdd_ctx->skip_acs_scan_timer);
+	vos_status = vos_timer_start( &hdd_ctx->skip_acs_scan_timer,
+			ACS_SCAN_EXPIRY_TIMEOUT_S * 1000);
+	if (!VOS_IS_STATUS_SUCCESS(vos_status))
+		hddLog(LOGE, FL("Failed to start ACS scan expiry timer"));
+	return VOS_STATUS_SUCCESS;
+}
+#else
+static VOS_STATUS hdd_handle_acs_scan_event(tpSap_Event sap_event,
+		hdd_adapter_t *adapter)
+{
+	return VOS_STATUS_SUCCESS;
+}
+#endif
+
 VOS_STATUS hdd_hostapd_SAPEventCB( tpSap_Event pSapEvent, v_PVOID_t usrDataForCallback)
 {
     hdd_adapter_t *pHostapdAdapter;
@@ -2147,19 +2219,8 @@ VOS_STATUS hdd_hostapd_SAPEventCB( tpSap_Event pSapEvent, v_PVOID_t usrDataForCa
             else
                 return hdd_chan_change_notify(pHostapdAdapter, dev,
                            pSapEvent->sapevt.sapChSelected.pri_ch);
-#ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
         case eSAP_ACS_SCAN_SUCCESS_EVENT:
-            pHddCtx->skip_acs_scan_status = eSAP_SKIP_ACS_SCAN;
-            hddLog(LOG1, FL("Reusing Last ACS scan result for %d sec"),
-                ACS_SCAN_EXPIRY_TIMEOUT_S);
-            vos_timer_stop( &pHddCtx->skip_acs_scan_timer);
-            vos_status = vos_timer_start( &pHddCtx->skip_acs_scan_timer,
-                                   ACS_SCAN_EXPIRY_TIMEOUT_S * 1000);
-            if (!VOS_IS_STATUS_SUCCESS(vos_status))
-                hddLog(LOGE, FL("Failed to start ACS scan expiry timer"));
-            return VOS_STATUS_SUCCESS;
-#endif
-
+            return hdd_handle_acs_scan_event(pSapEvent, pHostapdAdapter);
         case eSAP_DFS_NOL_GET:
             hddLog(VOS_TRACE_LEVEL_INFO,
                     FL("Received eSAP_DFS_NOL_GET event"));
diff --git a/CORE/HDD/src/wlan_hdd_main.c b/CORE/HDD/src/wlan_hdd_main.c
index 0268797bc8ef..dbb748ad9969 100644
--- a/CORE/HDD/src/wlan_hdd_main.c
+++ b/CORE/HDD/src/wlan_hdd_main.c
@@ -13070,6 +13070,11 @@ void hdd_wlan_exit(hdd_context_t *pHddCtx)
        hddLog(VOS_TRACE_LEVEL_ERROR,
             "%s: Cannot deallocate ACS Skip timer", __func__);
    }
+   spin_lock(&pHddCtx->acs_skip_lock);
+   vos_mem_free(pHddCtx->last_acs_channel_list);
+   pHddCtx->last_acs_channel_list = NULL;
+   pHddCtx->num_of_channels = 0;
+   spin_unlock(&pHddCtx->acs_skip_lock);
 #endif
 
    if (pConfig && !pConfig->enablePowersaveOffload)
@@ -13304,19 +13309,34 @@ void __hdd_wlan_exit(void)
 }
 
 #ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
+/**
+ * hdd_skip_acs_scan_timer_handler() - skip ACS scan timer timeout handler
+ * @data: pointer to hdd_context_t
+ *
+ * This function will reset acs_scan_status to eSAP_DO_NEW_ACS_SCAN.
+ * Then new ACS request will do a fresh scan without reusing the cached
+ * scan information.
+ *
+ * Return: void
+ */
 void hdd_skip_acs_scan_timer_handler(void * data)
 {
-    hdd_context_t *hdd_ctx = (hdd_context_t *) data;
-    hdd_adapter_t *ap_adapter;
+	hdd_context_t *hdd_ctx = (hdd_context_t *) data;
+	hdd_adapter_t *ap_adapter;
 
-    hddLog(LOG1, FL("ACS Scan result expired. Reset ACS scan skip"));
-    hdd_ctx->skip_acs_scan_status = eSAP_DO_NEW_ACS_SCAN;
+	hddLog(LOG1, FL("ACS Scan result expired. Reset ACS scan skip"));
+	hdd_ctx->skip_acs_scan_status = eSAP_DO_NEW_ACS_SCAN;
+	spin_lock(&hdd_ctx->acs_skip_lock);
+	vos_mem_free(hdd_ctx->last_acs_channel_list);
+	hdd_ctx->last_acs_channel_list = NULL;
+	hdd_ctx->num_of_channels = 0;
+	spin_unlock(&hdd_ctx->acs_skip_lock);
 
-    /* Get first SAP adapter to clear results */
-    ap_adapter = hdd_get_adapter(hdd_ctx, WLAN_HDD_SOFTAP);
-    if (!hdd_ctx->hHal || !ap_adapter)
-        return;
-    sme_ScanFlushResult(hdd_ctx->hHal, ap_adapter->sessionId);
+	/* Get first SAP adapter to clear results */
+	ap_adapter = hdd_get_adapter(hdd_ctx, WLAN_HDD_SOFTAP);
+	if (!hdd_ctx->hHal || !ap_adapter)
+		return;
+	sme_ScanFlushResult(hdd_ctx->hHal, ap_adapter->sessionId);
 }
 #endif
 
@@ -15514,6 +15534,7 @@ int hdd_wlan_startup(struct device *dev, v_VOID_t *hif_sc)
                   hdd_skip_acs_scan_timer_handler, (void *)pHddCtx);
    if (!VOS_IS_STATUS_SUCCESS(status))
         hddLog(LOGE, FL("Failed to init ACS Skip timer\n"));
+   spin_lock_init(&pHddCtx->acs_skip_lock);
 #endif
 
 #ifdef WLAN_FEATURE_NAN
diff --git a/CORE/SAP/inc/sapApi.h b/CORE/SAP/inc/sapApi.h
index 76c662b7c6c6..324173dd313d 100644
--- a/CORE/SAP/inc/sapApi.h
+++ b/CORE/SAP/inc/sapApi.h
@@ -189,9 +189,7 @@ typedef enum {
     eSAP_DFS_NOL_GET,  /* Event sent when user need to get the DFS NOL from CNSS */
     eSAP_DFS_NOL_SET,  /* Event sent when user need to set the DFS NOL to CNSS */
     eSAP_DFS_NO_AVAILABLE_CHANNEL, /* No ch available after DFS RADAR detect */
-#ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
     eSAP_ACS_SCAN_SUCCESS_EVENT,
-#endif
     eSAP_ACS_CHANNEL_SELECTED,
     eSAP_ECSA_CHANGE_CHAN_IND,
 } eSapHddEvent;
@@ -387,6 +385,18 @@ typedef struct sap_ChSelected_s {
 } tSap_ChSelectedEvent;
 
 /**
+ * struct tsap_acs_scan_complete_event - acs scan complete event
+ * @status: status of acs scan
+ * @channellist: acs scan channels
+ * @num_of_channels: number of channels
+ */
+struct tsap_acs_scan_complete_event{
+    uint8_t status;
+    uint8_t *channellist;
+    uint8_t num_of_channels;
+};
+
+/**
  * struct sap_ch_change_ind - channel change indication
  * @new_chan: channel to change
  */
@@ -420,6 +430,7 @@ typedef struct sap_Event_s {
         tSap_DfsNolInfo                           sapDfsNolInfo;    /*eSAP_DFS_NOL_XXX */
         /*eSAP_ACS_CHANNEL_SELECTED */
         tSap_ChSelectedEvent                      sapChSelected;
+        struct tsap_acs_scan_complete_event       sap_acs_scan_comp;
         struct sap_ch_change_ind                  sap_chan_cng_ind;
     } sapevt;
 } tSap_Event, *tpSap_Event;
diff --git a/CORE/SAP/src/sapApiLinkCntl.c b/CORE/SAP/src/sapApiLinkCntl.c
index 758ce58c9ef5..3944c0847b51 100644
--- a/CORE/SAP/src/sapApiLinkCntl.c
+++ b/CORE/SAP/src/sapApiLinkCntl.c
@@ -260,6 +260,7 @@ WLANSAP_ScanCallback
          * the result */
         vos_mem_free(psapContext->channelList);
         psapContext->channelList = NULL;
+        psapContext->num_of_channel = 0;
     }
 #endif
 
@@ -501,6 +502,7 @@ WLANSAP_PreStartBssAcsScanCallback
              */
             vos_mem_free(psapContext->channelList);
             psapContext->channelList = NULL;
+            psapContext->num_of_channel = 0;
         }
 #endif
 
diff --git a/CORE/SAP/src/sapFsm.c b/CORE/SAP/src/sapFsm.c
index e43e3cfb9a20..9e4fcac14c25 100644
--- a/CORE/SAP/src/sapFsm.c
+++ b/CORE/SAP/src/sapFsm.c
@@ -2764,7 +2764,7 @@ sapGotoChannelSel
                 scanRequest.requestType = eCSR_SCAN_SOFTAP_CHANNEL_RANGE;
 
                 sapContext->channelList = channelList;
-
+                sapContext->num_of_channel = numOfChannels;
 #endif
                 /* Set requestType to Full scan */
 
@@ -2825,6 +2825,7 @@ sapGotoChannelSel
                         sapContext->channel = sapContext->channelList[0];
                         vos_mem_free(sapContext->channelList);
                         sapContext->channelList = NULL;
+                        sapContext->num_of_channel = 0;
                     }
 #endif
                     if (VOS_TRUE == sapDoAcsPreStartBss)
@@ -3155,6 +3156,33 @@ sapGotoDisconnected
     return vosStatus;
 }
 
+#ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
+/**
+ * sap_handle_acs_scan_event() - handle acs scan event for SAP
+ * @sap_context: ptSapContext
+ * @sap_event: tSap_Event
+ * @status: status of acs scan
+ *
+ * The function is to handle the eSAP_ACS_SCAN_SUCCESS_EVENT event.
+ *
+ * Return: void
+ */
+static void sap_handle_acs_scan_event(ptSapContext sap_context,
+		tSap_Event *sap_event, eSapStatus status)
+{
+	sap_event->sapHddEventCode = eSAP_ACS_SCAN_SUCCESS_EVENT;
+	sap_event->sapevt.sap_acs_scan_comp.status = status;
+	sap_event->sapevt.sap_acs_scan_comp.num_of_channels =
+			sap_context->num_of_channel;
+	sap_event->sapevt.sap_acs_scan_comp.channellist =
+			sap_context->channelList;
+}
+#else
+static void sap_handle_acs_scan_event(ptSapContext sap_context,
+		tSap_Event *sap_event, eSapStatus status)
+{
+}
+#endif
 /*==========================================================================
   FUNCTION    sapSignalHDDevent
 
@@ -3261,14 +3289,17 @@ sapSignalHDDevent
             VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH,
                 "In %s, SAP event callback event = %s : %d", __func__,
                 "eSAP_DFS event", sapHddevent);
-#ifdef FEATURE_WLAN_AP_AP_ACS_OPTIMIZE
-        case eSAP_ACS_SCAN_SUCCESS_EVENT:
-#endif
             sapApAppEvent.sapHddEventCode = sapHddevent;
             sapApAppEvent.sapevt.sapStopBssCompleteEvent.status =
-                                                        (eSapStatus )context;
+                                           (eSapStatus )context;
+            break;
+        case eSAP_ACS_SCAN_SUCCESS_EVENT:
+            VOS_TRACE( VOS_MODULE_ID_SAP, VOS_TRACE_LEVEL_INFO_HIGH,
+                "In %s, SAP event callback event = %s : %d", __func__,
+                "ACS Scan event", sapHddevent);
+            sap_handle_acs_scan_event(sapContext, &sapApAppEvent,
+                        (eSapStatus)context);
             break;
-
         case eSAP_ACS_CHANNEL_SELECTED:
             sapApAppEvent.sapHddEventCode = sapHddevent;
             if ( eSAP_STATUS_SUCCESS == (eSapStatus )context)
diff --git a/CORE/SAP/src/sapInternal.h b/CORE/SAP/src/sapInternal.h
index 77ed03e00a97..c5bc6cf86ab1 100644
--- a/CORE/SAP/src/sapInternal.h
+++ b/CORE/SAP/src/sapInternal.h
@@ -246,6 +246,7 @@ typedef struct sSapContext {
     v_U32_t           nStaAddIeLength;
     v_U8_t            pStaAddIE[MAX_ASSOC_IND_IE_LEN];
     v_U8_t            *channelList;
+    uint8_t            num_of_channel;
     tSapChannelListInfo SapChnlList;
     uint16_t           vht_channel_width;
     uint16_t           ch_width_orig;