From 972337444b564b04e7a169ff37da72435d730ded Mon Sep 17 00:00:00 2001
From: Florian Pose <fp@igh.de>
Date: Tue, 14 May 2024 18:37:17 +0200
Subject: [PATCH] Retry receiving an EoE set IP parameter response.

---
 master/fsm_eoe.c | 26 +++++++++++++++++++++-----
 master/fsm_eoe.h |  1 +
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/master/fsm_eoe.c b/master/fsm_eoe.c
index 73c2ef56..abfdb781 100644
--- a/master/fsm_eoe.c
+++ b/master/fsm_eoe.c
@@ -61,6 +61,7 @@ void ec_fsm_eoe_init(
     fsm->datagram = NULL;
     fsm->jiffies_start = 0;
     fsm->request = NULL;
+    fsm->frame_type_retries = 0;
 }
 
 /****************************************************************************/
@@ -313,6 +314,7 @@ void ec_fsm_eoe_set_ip_request(
     ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
     fsm->retries = EC_FSM_RETRIES;
     fsm->state = ec_fsm_eoe_set_ip_check;
+    fsm->frame_type_retries = 10;
 }
 
 /****************************************************************************/
@@ -431,11 +433,25 @@ void ec_fsm_eoe_set_ip_response(
     frame_type = EC_READ_U8(data) & 0x0f;
 
     if (frame_type != EC_EOE_FRAMETYPE_SET_IP_RES) {
-        EC_SLAVE_ERR(slave, "Received no set IP parameter response"
-                " (frame type %x).\n", frame_type);
-        ec_print_data(data, rec_size);
-        fsm->state = ec_fsm_eoe_error;
-        return;
+        if (master->debug_level) {
+            EC_SLAVE_DBG(slave, 0, "Received no set IP parameter response"
+                    " (frame type %x).\n", frame_type);
+            ec_print_data(data, rec_size);
+        }
+        if (fsm->frame_type_retries--) {
+            // there may be an EoE segment left in the mailbox.
+            // discard it and receive again.
+            fsm->jiffies_start = fsm->datagram->jiffies_sent;
+            ec_slave_mbox_prepare_check(slave, datagram); // can not fail.
+            fsm->retries = EC_FSM_RETRIES;
+            fsm->state = ec_fsm_eoe_set_ip_check;
+            return;
+        }
+        else {
+            EC_SLAVE_ERR(slave, "Received no set IP parameter response.\n");
+            fsm->state = ec_fsm_eoe_error;
+            return;
+        }
     }
 
     req->result = EC_READ_U16(data + 2);
diff --git a/master/fsm_eoe.h b/master/fsm_eoe.h
index 3809a462..7f901bdd 100644
--- a/master/fsm_eoe.h
+++ b/master/fsm_eoe.h
@@ -48,6 +48,7 @@ struct ec_fsm_eoe {
     ec_datagram_t *datagram; /**< Datagram used in the previous step. */
     unsigned long jiffies_start; /**< Timestamp. */
     ec_eoe_request_t *request; /**< EoE request */
+    unsigned int frame_type_retries; /**< retries upon wrong frame type. */
 };
 
 /****************************************************************************/