1 files changed, 31 insertions, 14 deletions
diff --git a/cpukit/score/src/coremutexseize.c b/cpukit/score/src/coremutexseize.c
index 3fc3765ef4..d5f85c5fad 100644
--- a/cpukit/score/src/coremutexseize.c
+++ b/cpukit/score/src/coremutexseize.c
@@ -21,7 +21,6 @@
 #include <rtems/system.h>
 #include <rtems/score/isr.h>
 #include <rtems/score/coremuteximpl.h>
-#include <rtems/score/schedulerimpl.h>
 #include <rtems/score/statesimpl.h>
 #include <rtems/score/thread.h>
 
@@ -53,29 +52,47 @@ void _CORE_mutex_Seize_interrupt_blocking(
   ISR_lock_Context    *lock_context
 )
 {
-  _Thread_queue_Enter_critical_section( &the_mutex->Wait_queue );
-  executing->Wait.queue = &the_mutex->Wait_queue;
-  _Thread_Disable_dispatch();
-  _ISR_lock_ISR_enable( lock_context );
+#if !defined(RTEMS_SMP)
+  /*
+   * We must disable thread dispatching here since we enable the interrupts for
+   * priority inheritance mutexes.
+   */
+  _Thread_Dispatch_disable();
+#endif
 
   if ( _CORE_mutex_Is_inherit_priority( &the_mutex->Attributes ) ) {
     Thread_Control *holder = the_mutex->holder;
 
-    _Scheduler_Change_priority_if_higher(
-      _Scheduler_Get( holder ),
-      holder,
-      executing->current_priority,
-      false
-    );
+#if !defined(RTEMS_SMP)
+    /*
+     * To enable interrupts here works only since exactly one executing thread
+     * exists and only threads are allowed to seize and surrender mutexes with
+     * the priority inheritance protocol.  On SMP configurations more than one
+     * executing thread may exist, so here we must not release the lock, since
+     * otherwise the current holder may be no longer the holder of the mutex
+     * once we released the lock.
+     */
+    _Thread_queue_Release( &the_mutex->Wait_queue, lock_context );
+#endif
+
+    _Thread_Raise_priority( holder, executing->current_priority );
+
+#if !defined(RTEMS_SMP)
+    _Thread_queue_Acquire( &the_mutex->Wait_queue, lock_context );
+#endif
   }
 
-  _Thread_queue_Enqueue(
+  _Thread_queue_Enqueue_critical(
     &the_mutex->Wait_queue,
     executing,
     STATES_WAITING_FOR_MUTEX,
-    timeout
+    timeout,
+    CORE_MUTEX_TIMEOUT,
+    lock_context
   );
 
-  _Thread_Enable_dispatch();
+#if !defined(RTEMS_SMP)
+  _Thread_Dispatch_enable( _Per_CPU_Get() );
+#endif
 }