broadband-modem: new initialization step when failed/locked

Instead of using the firmware step as fallback when the modem goes
into failed or locked state, use an independent step in the
initialization state machine, just to make it clearer.

src/mm-broadband-modem.c

@@ -11000,6 +11000,7 @@ typedef enum {
     INITIALIZE_STEP_IFACE_TIME,
     INITIALIZE_STEP_IFACE_SIGNAL,
     INITIALIZE_STEP_IFACE_OMA,
+    INITIALIZE_STEP_FALLBACK_LIMITED,
     INITIALIZE_STEP_IFACE_FIRMWARE,
     INITIALIZE_STEP_SIM_HOT_SWAP,
     INITIALIZE_STEP_IFACE_SIMPLE,
@@ -11106,9 +11107,9 @@ iface_modem_initialize_ready (MMBroadbandModem *self,
 
         mm_iface_modem_update_failed_state (MM_IFACE_MODEM (self), failed_reason);
 
-        /* Jump to the firmware step. We allow firmware switching even in failed
-         * state */
-        ctx->step = INITIALIZE_STEP_IFACE_FIRMWARE;
+        /* Jump to the fallback step when on failure, we will allow some additional
+         * interfaces even in failed state. */
+        ctx->step = INITIALIZE_STEP_FALLBACK_LIMITED;
         initialize_step (task);
         return;
     }
@@ -11121,9 +11122,9 @@ iface_modem_initialize_ready (MMBroadbandModem *self,
      * the initialization sequence. Instead, we will re-initialize once
      * we are unlocked. */
     if (ctx->self->priv->modem_state == MM_MODEM_STATE_LOCKED) {
-        /* Jump to the Firmware interface. We do allow modems to export
-         * both the Firmware and Simple interfaces when locked. */
-        ctx->step = INITIALIZE_STEP_IFACE_FIRMWARE;
+        /* Jump to the fallback step when locked, we will allow some additional
+         * interfaces even in locked state. */
+        ctx->step = INITIALIZE_STEP_FALLBACK_LIMITED;
         initialize_step (task);
         return;
     }
@@ -11323,6 +11324,12 @@ initialize_step (GTask *task)
                                        task);
         return;
 
+    case INITIALIZE_STEP_FALLBACK_LIMITED:
+        /* All the initialization steps after this one will be run both on
+         * successful and locked/failed initializations.
+         * Fall down to next step */
+        ctx->step++;
+
     case INITIALIZE_STEP_IFACE_FIRMWARE:
         /* Initialize the Firmware interface */
         mm_iface_modem_firmware_initialize (MM_IFACE_MODEM_FIRMWARE (ctx->self),