DataFlash: make EnableWrites a frontend thing

libraries/DataFlash/DataFlash.cpp

@@ -109,6 +109,8 @@ void DataFlash_Class::Init(const struct LogStructure *structures, uint8_t num_ty
 
     Prep();
 
+    EnableWrites(true);
+
     GCS_MAVLINK::send_statustext_all(MAV_SEVERITY_INFO, "Prepared log system");
 }
 
@@ -458,10 +460,6 @@ bool DataFlash_Class::logging_started(void) {
     return false;
 }
 
-void DataFlash_Class::EnableWrites(bool enable) {
-    FOR_EACH_BACKEND(EnableWrites(enable));
-}
-
 // for DataFlash_MAVLink
 void DataFlash_Class::remote_log_block_status_msg(mavlink_channel_t chan,
                                                   mavlink_message_t* msg) {

libraries/DataFlash/DataFlash.h

@@ -104,7 +104,8 @@ public:
     /* poke backends to start if they're not already started */
     void StartUnstartedLogging(void);
 
-    void EnableWrites(bool enable);
+    void EnableWrites(bool enable) { _writes_enabled = enable; }
+    bool WritesEnabled() const { return _writes_enabled; }
 
     void StopLogging();
 
@@ -288,4 +289,7 @@ private:
 
     // possibly expensive calls to start log system:
     void Prep();
+
+    bool _writes_enabled;
+
 };

libraries/DataFlash/DataFlash_Backend.cpp

@@ -262,7 +262,7 @@ bool DataFlash_Backend::Log_Write(const uint8_t msg_type, va_list arg_list, bool
 
 bool DataFlash_Backend::WritesOK() const
 {
-    if (!_writes_enabled) {
+    if (!_front.WritesEnabled()) {
         return false;
     }
     if (!_front.vehicle_is_armed() && !_front.log_while_disarmed()) {

libraries/DataFlash/DataFlash_Backend.h

@@ -51,12 +51,9 @@ public:
     virtual void ShowDeviceInfo(AP_HAL::BetterStream *port) = 0;
     virtual void ListAvailableLogs(AP_HAL::BetterStream *port) = 0;
 
-    void EnableWrites(bool enable) { _writes_enabled = enable; }
     virtual bool logging_started(void) const { return log_write_started; }
 
-    virtual void Init() {
-        _writes_enabled = true;
-    }
+    virtual void Init() { }
 
     void set_mission(const AP_Mission *mission);
 
@@ -142,8 +139,6 @@ protected:
 
     virtual bool WritesOK() const;
 
-    bool _writes_enabled = false;
-
     /*
       read a block
     */