qcacld-3.0: Fix scan failure

Scan pending flag is maintained per adapter but it is getting
reset only when all the scans on all the adapters are
completed.
Update logic to reset scan pending flag when there is no pending
scan on that particular adapter.

Change-Id: If019f6619fa11a505c489a12474b5f550982a727
CRs-Fixed: 990466

core/hdd/src/wlan_hdd_scan.c

@@ -505,6 +505,48 @@ static int hdd_indicate_scan_result(hdd_scan_info_t *scanInfo,
 	return 0;
 }
 
+/**
+ * wlan_hdd_is_scan_pending() - Utility function to check pending scans
+ * @adapter: Pointer to the adapter
+ *
+ * Utility function to check pending scans on a particular adapter
+ *
+ * Return: true if scans are pending, false otherwise
+ */
+static bool wlan_hdd_is_scan_pending(hdd_adapter_t *adapter)
+{
+	hdd_context_t *hdd_ctx = WLAN_HDD_GET_CTX(adapter);
+	qdf_list_node_t *pnode = NULL, *ppnode = NULL;
+	struct hdd_scan_req *hdd_scan_req;
+
+	qdf_spin_lock(&hdd_ctx->hdd_scan_req_q_lock);
+
+	if (qdf_list_empty(&hdd_ctx->hdd_scan_req_q)) {
+		qdf_spin_unlock(&hdd_ctx->hdd_scan_req_q_lock);
+		return false;
+	}
+
+	if (QDF_STATUS_SUCCESS != qdf_list_peek_front(&hdd_ctx->hdd_scan_req_q,
+							&ppnode)) {
+		qdf_spin_unlock(&hdd_ctx->hdd_scan_req_q_lock);
+		hdd_err("Failed to remove Scan Req from queue");
+		return false;
+	}
+
+	do {
+		pnode = ppnode;
+		hdd_scan_req = (struct hdd_scan_req *)pnode;
+		/* Any scan pending on the adapter */
+		if (adapter == hdd_scan_req->adapter) {
+			qdf_spin_unlock(&hdd_ctx->hdd_scan_req_q_lock);
+			return true;
+		}
+	} while (QDF_STATUS_SUCCESS ==
+		qdf_list_peek_next(&hdd_ctx->hdd_scan_req_q, pnode, &ppnode));
+
+	qdf_spin_unlock(&hdd_ctx->hdd_scan_req_q_lock);
+	return false;
+}
 
 /**
  * wlan_hdd_scan_request_enqueue() - enqueue Scan Request
@@ -647,7 +689,6 @@ hdd_scan_request_callback(tHalHandle halHandle, void *pContext,
 	uint8_t source;
 	struct cfg80211_scan_request *req;
 	uint32_t timestamp;
-	uint32_t size = 0;
 
 	ENTER();
 	hddLog(LOGW,
@@ -673,12 +714,9 @@ hdd_scan_request_callback(tHalHandle halHandle, void *pContext,
 		hdd_err("Got unexpected request struct for Scan id %d",
 			scanId);
 
-	qdf_spin_lock(&hddctx->hdd_scan_req_q_lock);
-	size = qdf_list_size(&(hddctx->hdd_scan_req_q));
-	if (!size)
-		/* Scan is no longer pending */
+	/* Scan is no longer pending */
+	if (!wlan_hdd_is_scan_pending(pAdapter))
 		pAdapter->scan_info.mScanPending = false;
-	qdf_spin_unlock(&hddctx->hdd_scan_req_q_lock);
 
 	/* notify any applications that may be interested */
 	memset(&wrqu, '\0', sizeof(wrqu));
@@ -1138,14 +1176,12 @@ static QDF_STATUS hdd_cfg80211_scan_done_callback(tHalHandle halHandle,
 		aborted = true;
 	}
 
-	qdf_spin_lock(&hddctx->hdd_scan_req_q_lock);
-	size = qdf_list_size(&(hddctx->hdd_scan_req_q));
-	if (!size) {
+	if (!wlan_hdd_is_scan_pending(pAdapter)) {
 		/* Scan is no longer pending */
 		pScanInfo->mScanPending = false;
 		complete(&pScanInfo->abortscan_event_var);
 	}
-	qdf_spin_unlock(&hddctx->hdd_scan_req_q_lock);
+
 	/*
 	 * Scan can be triggred from NL or vendor scan
 	 * - If scan is triggered from NL then cfg80211 scan done should be
@@ -1159,7 +1195,10 @@ static QDF_STATUS hdd_cfg80211_scan_done_callback(tHalHandle halHandle,
 		hdd_vendor_scan_callback(pAdapter, req, aborted);
 
 allow_suspend:
+	qdf_spin_lock(&hddctx->hdd_scan_req_q_lock);
+	size = qdf_list_size(&hddctx->hdd_scan_req_q);
 	if (!size) {
+		qdf_spin_unlock(&hddctx->hdd_scan_req_q_lock);
 		/* release the wake lock at the end of the scan */
 		hdd_allow_suspend(WIFI_POWER_EVENT_WAKELOCK_SCAN);
 
@@ -1171,6 +1210,9 @@ allow_suspend:
 		 */
 		hdd_prevent_suspend_timeout(1000,
 			WIFI_POWER_EVENT_WAKELOCK_SCAN);
+	} else {
+		/* Release the spin lock */
+		qdf_spin_unlock(&hddctx->hdd_scan_req_q_lock);
 	}
 
 #ifdef FEATURE_WLAN_TDLS