From 12bf160f3d90b1d1ed85acd12d2ae5db5e27a0aa Mon Sep 17 00:00:00 2001
From: Zim Kalinowski <zim.kalinowski@zoho.com>
Date: Wed, 25 Aug 2021 15:59:00 +0800
Subject: [PATCH] vCoRoutineScheduleFix

(cherry picked from commit 1edbd44db107225b7bc6342a7da5680cc12ad22f)
---
 components/freertos/croutine.c | 47 +++++++++++++++++++---------------
 1 file changed, 26 insertions(+), 21 deletions(-)

diff --git a/components/freertos/croutine.c b/components/freertos/croutine.c
index a4628f4ddb..8be115f78c 100644
--- a/components/freertos/croutine.c
+++ b/components/freertos/croutine.c
@@ -281,31 +281,36 @@
 
     void vCoRoutineSchedule( void )
     {
-        /* See if any co-routines readied by events need moving to the ready lists. */
-        prvCheckPendingReadyList();
-
-        /* See if any delayed co-routines have timed out. */
-        prvCheckDelayedList();
-
-        /* Find the highest priority queue that contains ready co-routines. */
-        while( listLIST_IS_EMPTY( &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) ) )
+        /* Only run a co-routine after prvInitialiseCoRoutineLists() has been
+         * called.  prvInitialiseCoRoutineLists() is called automatically when a
+         * co-routine is created. */
+        if( pxDelayedCoRoutineList != NULL )
         {
-            if( uxTopCoRoutineReadyPriority == 0 )
+            /* See if any co-routines readied by events need moving to the ready lists. */
+            prvCheckPendingReadyList();
+
+            /* See if any delayed co-routines have timed out. */
+            prvCheckDelayedList();
+
+            /* Find the highest priority queue that contains ready co-routines. */
+            while( listLIST_IS_EMPTY( &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) ) )
             {
-                /* No more co-routines to check. */
-                return;
+                if( uxTopCoRoutineReadyPriority == 0 )
+                {
+                    /* No more co-routines to check. */
+                    return;
+                }
+
+                --uxTopCoRoutineReadyPriority;
             }
-            --uxTopCoRoutineReadyPriority;
+
+            /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the co-routines
+             * of the same priority get an equal share of the processor time. */
+            listGET_OWNER_OF_NEXT_ENTRY( pxCurrentCoRoutine, &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) );
+
+            /* Call the co-routine. */
+            ( pxCurrentCoRoutine->pxCoRoutineFunction )( pxCurrentCoRoutine, pxCurrentCoRoutine->uxIndex );
         }
-
-        /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the co-routines
-         * of the same priority get an equal share of the processor time. */
-        listGET_OWNER_OF_NEXT_ENTRY( pxCurrentCoRoutine, &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) );
-
-        /* Call the co-routine. */
-        ( pxCurrentCoRoutine->pxCoRoutineFunction )( pxCurrentCoRoutine, pxCurrentCoRoutine->uxIndex );
-
-        return;
     }
 /*-----------------------------------------------------------*/