2003-02-11 Joel Sherrill <joel@OARcorp.com>

	* irq.c: Rework logic that decides when to call
	_Thread_Dispatch.  Analysis by Sergei Organov <osv@javad.ru>
	determined that _ISR_Signals_to_thread_executing was not being
	honored and/or cleared properly.

2 files changed, 19 insertions, 5 deletions

diff --git a/cpukit/score/cpu/c4x/ChangeLog b/cpukit/score/cpu/c4x/ChangeLog
index 0a3b7d947a..1c88481777 100644
--- a/cpukit/score/cpu/c4x/ChangeLog
+++ b/cpukit/score/cpu/c4x/ChangeLog
@@ -1,3 +1,10 @@
+2003-02-11	Joel Sherrill <joel@OARcorp.com>
+
+	* irq.c: Rework logic that decides when to call
+	_Thread_Dispatch.  Analysis by Sergei Organov <osv@javad.ru>
+	determined that _ISR_Signals_to_thread_executing was not being
+	honored and/or cleared properly.
+
 2002-12-11	Ralf Corsepius <corsepiu@faw.uni-ulm.de>
 
 	* configure.ac: Require autoconf-2.57 + automake-1.7.2.
diff --git a/cpukit/score/cpu/c4x/irq.c b/cpukit/score/cpu/c4x/irq.c
index 055bae40c4..43d6c1471c 100644
--- a/cpukit/score/cpu/c4x/irq.c
+++ b/cpukit/score/cpu/c4x/irq.c
@@ -73,10 +73,17 @@ void __ISR_Handler(unsigned32 vector, void *isr_sp)
   _Thread_Dispatch_disable_level--;
 
   _CPU_ISR_Enable( level );
-  if ( _Thread_Dispatch_disable_level == 0 ) {
-    if ( _Context_Switch_necessary || !_ISR_Signals_to_thread_executing ) {
-       _ISR_Signals_to_thread_executing = FALSE;
-       _Thread_Dispatch();
-    }
+
+  if ( _ISR_Nest_level )
+    return;
+
+  if ( _Thread_Dispatch_disable_level ) {
+    _ISR_Signals_to_thread_executing = FALSE;
+    return;
+  }
+
+  if ( _Context_Switch_necessary || _ISR_Signals_to_thread_executing ) {
+    _ISR_Signals_to_thread_executing = FALSE;
+    _Thread_Dispatch();
   }
 }