diff -r af21f0bdc7c9 -r 2b9c78543663 master/voe_handler.c
--- a/master/voe_handler.c	Thu Sep 06 14:21:02 2012 +0200
+++ b/master/voe_handler.c	Mon Nov 03 15:20:05 2014 +0100
@@ -88,7 +88,6 @@
     voe->request_state = EC_INT_REQUEST_INIT;
 
     ec_datagram_init(&voe->datagram);
-    ec_mbox_init(&voe->mbox,&voe->datagram);
     return ec_datagram_prealloc(&voe->datagram,
             size + EC_MBOX_HEADER_SIZE + EC_VOE_HEADER_SIZE);
 }
@@ -101,13 +100,14 @@
         ec_voe_handler_t *voe /**< VoE handler. */
         )
 {
-    ec_mbox_clear(&voe->mbox);
     ec_datagram_clear(&voe->datagram);
 }
 
 /*****************************************************************************/
 
 /** Get usable memory size.
+ *
+ * \return Memory size.
  */
 size_t ec_voe_handler_mem_size(
         const ec_voe_handler_t *voe /**< VoE handler. */
@@ -192,8 +192,9 @@
 {
     if (voe->config->slave) { // FIXME locking?
         voe->state(voe);
-        if (voe->request_state == EC_INT_REQUEST_BUSY)
-            ec_slave_mbox_queue_datagrams(voe->config->slave,&voe->mbox);
+        if (voe->request_state == EC_INT_REQUEST_BUSY) {
+            ec_master_queue_datagram(voe->config->master, &voe->datagram);
+        }
     } else {
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;
@@ -226,7 +227,7 @@
         return;
     }
 
-    data = ec_slave_mbox_prepare_send(slave, &voe->mbox,
+    data = ec_slave_mbox_prepare_send(slave, &voe->datagram,
             EC_MBOX_TYPE_VOE, EC_VOE_HEADER_SIZE + voe->data_size);
     if (IS_ERR(data)) {
         voe->state = ec_voe_handler_state_error;
@@ -249,22 +250,22 @@
  */
 void ec_voe_handler_state_write_response(ec_voe_handler_t *voe)
 {
-    ec_mailbox_t *mbox = &voe->mbox;
-    ec_slave_t *slave = voe->config->slave;
-
-    if (ec_mbox_is_datagram_state(mbox,EC_DATAGRAM_TIMED_OUT) && voe->retries--)
-        return;
-
-    if (!ec_mbox_is_datagram_state(mbox,EC_DATAGRAM_RECEIVED)) {
+    ec_datagram_t *datagram = &voe->datagram;
+    ec_slave_t *slave = voe->config->slave;
+
+    if (datagram->state == EC_DATAGRAM_TIMED_OUT && voe->retries--)
+        return;
+
+    if (datagram->state != EC_DATAGRAM_RECEIVED) {
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;
         EC_SLAVE_ERR(slave, "Failed to receive VoE write request datagram: ");
-        ec_datagram_print_state(mbox->datagram);
-        return;
-    }
-
-    if (!ec_mbox_is_datagram_wc(mbox,1)) {
-        if (ec_mbox_is_datagram_wc(mbox,0)) {
+        ec_datagram_print_state(datagram);
+        return;
+    }
+
+    if (datagram->working_counter != 1) {
+        if (!datagram->working_counter) {
             unsigned long diff_ms =
                 (jiffies - voe->jiffies_start) * 1000 / HZ;
             if (diff_ms < EC_VOE_RESPONSE_TIMEOUT) {
@@ -278,7 +279,7 @@
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;
         EC_SLAVE_ERR(slave, "Reception of VoE write request failed: ");
-        ec_datagram_print_wc_error(mbox->datagram);
+        ec_datagram_print_wc_error(datagram);
         return;
     }
 
@@ -294,7 +295,7 @@
  */
 void ec_voe_handler_state_read_start(ec_voe_handler_t *voe)
 {
-    ec_mailbox_t *mbox = &voe->mbox;
+    ec_datagram_t *datagram = &voe->datagram;
     ec_slave_t *slave = voe->config->slave;
 
     EC_SLAVE_DBG(slave, 1, "Reading VoE data.\n");
@@ -306,7 +307,7 @@
         return;
     }
 
-    ec_slave_mbox_prepare_check(slave, mbox); // can not fail.
+    ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
 
     voe->jiffies_start = jiffies;
     voe->retries = EC_FSM_RETRIES;
@@ -319,32 +320,32 @@
  */
 void ec_voe_handler_state_read_check(ec_voe_handler_t *voe)
 {
-    ec_mailbox_t *mbox = &voe->mbox;
-    ec_slave_t *slave = voe->config->slave;
-
-    if (ec_mbox_is_datagram_state(mbox,EC_DATAGRAM_TIMED_OUT) && voe->retries--)
-        return;
-
-    if (!ec_mbox_is_datagram_state(mbox,EC_DATAGRAM_RECEIVED)) {
+    ec_datagram_t *datagram = &voe->datagram;
+    ec_slave_t *slave = voe->config->slave;
+
+    if (datagram->state == EC_DATAGRAM_TIMED_OUT && voe->retries--)
+        return;
+
+    if (datagram->state != EC_DATAGRAM_RECEIVED) {
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;
         EC_SLAVE_ERR(slave, "Failed to receive VoE mailbox check datagram: ");
-        ec_datagram_print_state(mbox->datagram);
-        return;
-    }
-
-    if (!ec_mbox_is_datagram_wc(mbox,1)) {
+        ec_datagram_print_state(datagram);
+        return;
+    }
+
+    if (datagram->working_counter != 1) {
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;
         EC_SLAVE_ERR(slave, "Reception of VoE mailbox check"
                 " datagram failed: ");
-        ec_datagram_print_wc_error(mbox->datagram);
-        return;
-    }
-
-    if (!ec_slave_mbox_check(mbox)) {
+        ec_datagram_print_wc_error(datagram);
+        return;
+    }
+
+    if (!ec_slave_mbox_check(datagram)) {
         unsigned long diff_ms =
-            (mbox->datagram->jiffies_received - voe->jiffies_start) * 1000 / HZ;
+            (datagram->jiffies_received - voe->jiffies_start) * 1000 / HZ;
         if (diff_ms >= EC_VOE_RESPONSE_TIMEOUT) {
             voe->state = ec_voe_handler_state_error;
             voe->request_state = EC_INT_REQUEST_FAILURE;
@@ -352,13 +353,13 @@
             return;
         }
 
-        ec_slave_mbox_prepare_check(slave, mbox); // can not fail.
+        ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
         voe->retries = EC_FSM_RETRIES;
         return;
     }
 
     // Fetch response
-    ec_slave_mbox_prepare_fetch(slave, mbox); // can not fail.
+    ec_slave_mbox_prepare_fetch(slave, datagram); // can not fail.
     voe->retries = EC_FSM_RETRIES;
     voe->state = ec_voe_handler_state_read_response;
 }
@@ -369,32 +370,32 @@
  */
 void ec_voe_handler_state_read_response(ec_voe_handler_t *voe)
 {
-    ec_mailbox_t *mbox = &voe->mbox;
+    ec_datagram_t *datagram = &voe->datagram;
     ec_slave_t *slave = voe->config->slave;
     ec_master_t *master = voe->config->master;
     uint8_t *data, mbox_prot;
     size_t rec_size;
 
-    if (ec_mbox_is_datagram_state(mbox,EC_DATAGRAM_TIMED_OUT) && voe->retries--)
-        return;
-
-    if (!ec_mbox_is_datagram_state(mbox,EC_DATAGRAM_RECEIVED)) {
+    if (datagram->state == EC_DATAGRAM_TIMED_OUT && voe->retries--)
+        return;
+
+    if (datagram->state != EC_DATAGRAM_RECEIVED) {
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;
         EC_SLAVE_ERR(slave, "Failed to receive VoE read datagram: ");
-        ec_datagram_print_state(mbox->datagram);
-        return;
-    }
-
-    if (!ec_mbox_is_datagram_wc(mbox,1)) {
+        ec_datagram_print_state(datagram);
+        return;
+    }
+
+    if (datagram->working_counter != 1) {
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;
         EC_SLAVE_ERR(slave, "Reception of VoE read response failed: ");
-        ec_datagram_print_wc_error(mbox->datagram);
-        return;
-    }
-
-    data = ec_slave_mbox_fetch(slave, mbox, &mbox_prot, &rec_size);
+        ec_datagram_print_wc_error(datagram);
+        return;
+    }
+
+    data = ec_slave_mbox_fetch(slave, datagram, &mbox_prot, &rec_size);
     if (IS_ERR(data)) {
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;
@@ -434,7 +435,7 @@
  */
 void ec_voe_handler_state_read_nosync_start(ec_voe_handler_t *voe)
 {
-    ec_mailbox_t *mbox = &voe->mbox;
+    ec_datagram_t *datagram = &voe->datagram;
     ec_slave_t *slave = voe->config->slave;
 
     EC_SLAVE_DBG(slave, 1, "Reading VoE data.\n");
@@ -446,7 +447,7 @@
         return;
     }
 
-    ec_slave_mbox_prepare_fetch(slave, mbox); // can not fail.
+    ec_slave_mbox_prepare_fetch(slave, datagram); // can not fail.
 
     voe->jiffies_start = jiffies;
     voe->retries = EC_FSM_RETRIES;
@@ -460,39 +461,39 @@
  */
 void ec_voe_handler_state_read_nosync_response(ec_voe_handler_t *voe)
 {
-    ec_mailbox_t *mbox = &voe->mbox;
+    ec_datagram_t *datagram = &voe->datagram;
     ec_slave_t *slave = voe->config->slave;
     ec_master_t *master = voe->config->master;
     uint8_t *data, mbox_prot;
     size_t rec_size;
 
-    if (ec_mbox_is_datagram_state(mbox,EC_DATAGRAM_TIMED_OUT) && voe->retries--)
-        return;
-
-    if (!ec_mbox_is_datagram_state(mbox,EC_DATAGRAM_RECEIVED)) {
+    if (datagram->state == EC_DATAGRAM_TIMED_OUT && voe->retries--)
+        return;
+
+    if (datagram->state != EC_DATAGRAM_RECEIVED) {
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;
         EC_SLAVE_ERR(slave, "Failed to receive VoE read datagram: ");
-        ec_datagram_print_state(mbox->datagram);
-        return;
-    }
-
-    if (ec_mbox_is_datagram_wc(mbox,0)) {
+        ec_datagram_print_state(datagram);
+        return;
+    }
+
+    if (datagram->working_counter == 0) {
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;
         EC_SLAVE_DBG(slave, 1, "Slave did not send VoE data.\n");
         return;
     }
 
-    if (!ec_mbox_is_datagram_wc(mbox,1)) {
+    if (datagram->working_counter != 1) {
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;
         EC_SLAVE_WARN(slave, "Reception of VoE read response failed: ");
-        ec_datagram_print_wc_error(mbox->datagram);
-        return;
-    }
-
-    if (!(data = ec_slave_mbox_fetch(slave, mbox,
+        ec_datagram_print_wc_error(datagram);
+        return;
+    }
+
+    if (!(data = ec_slave_mbox_fetch(slave, datagram,
                     &mbox_prot, &rec_size))) {
         voe->state = ec_voe_handler_state_error;
         voe->request_state = EC_INT_REQUEST_FAILURE;