Merge pull request ARMmbed#14511 from paul-szczepanek-arm/scan-start-check

BLE: Fix start scan command not returning error if parameters haven't been set

Author: 0xc0170

connectivity/FEATURE_BLE/source/generic/GapImpl.cpp

@@ -1221,6 +1221,7 @@ ble_error_t Gap::reset()
 #endif // BLE_FEATURE_PRIVACY
 
 #if BLE_ROLE_OBSERVER
+    _scan_parameters_set = false;
     _scan_timeout.detach();
 #endif
 
@@ -3562,6 +3563,8 @@ ble_error_t Gap::setScanParameters(const ScanParameters &params)
             params.getCodedPhyConfiguration().getWindow().value()
         };
 
+        _scan_parameters_set = true;
+
         return _pal_gap.set_extended_scan_parameters(
             params.getOwnAddressType(),
             params.getFilter(),
@@ -3581,6 +3584,8 @@ ble_error_t Gap::setScanParameters(const ScanParameters &params)
         ScanParameters::phy_configuration_t legacy_configuration =
             params.get1mPhyConfiguration();
 
+        _scan_parameters_set = true;
+
         return _pal_gap.set_scan_parameters(
             legacy_configuration.isActiveScanningSet(),
             legacy_configuration.getInterval().value(),
@@ -3613,6 +3618,11 @@ ble_error_t Gap::startScan(
         return BLE_STACK_BUSY;
     }
 
+    if (!_scan_parameters_set) {
+        tr_error("Scan parameters not set.");
+        return BLE_ERROR_OPERATION_NOT_PERMITTED;
+    }
+
     _scan_requested_duration = duration;
     _scan_requested_filtering = filtering;
     _scan_requested_period = period;

connectivity/FEATURE_BLE/source/generic/GapImpl.h

@@ -991,6 +991,10 @@ class Gap :
 
 
     bool _user_manage_connection_parameter_requests : 1;
+#if BLE_ROLE_OBSERVER
+    bool _scan_parameters_set : 1 = false;
+#endif // BLE_ROLE_OBSERVER
+
 };
 
 } // namespace impl