Fix an issue for architectures where interrupt numbers and vector numbers do not match 1-to-1

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4258 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 18 insertions, 4 deletions

diff --git a/nuttx/sched/irq_attach.c b/nuttx/sched/irq_attach.c
index 85f6b93ed..99fb62078 100644
--- a/nuttx/sched/irq_attach.c
+++ b/nuttx/sched/irq_attach.c
@@ -1,8 +1,8 @@
 /****************************************************************************
  * sched/irq_attach.c
  *
- *   Copyright (C) 2007-2008, 2010 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Copyright (C) 2007-2008, 2010, 2012 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -91,9 +91,23 @@ int irq_attach(int irq, xcpt_t isr)
       state = irqsave();
       if (isr == NULL)
         {
-#ifndef CONFIG_ARCH_NOINTC
-           up_disable_irq(irq);
+          /* Disable the interrupt if we can before detaching it.  We might
+           * not be able to do this if:  (1) the device does not have a 
+           * centralized interrupt controller (so up_disable_irq() is not
+           * supported.  Or (2) if the device has different number for vector
+           * numbers and IRQ numbers (in that case, we don't know the correct
+           * IRQ number to use to disable the interrupt.  In those cases, the
+           * code will just need to be careful that it disables all interrupt
+           * sources before detaching from the interrupt vector.
+           */
+
+#if !defined(CONFIG_ARCH_NOINTC) && !defined(CONFIG_ARCH_VECNOTIRQ)
+          up_disable_irq(irq);
 #endif
+          /* Detaching the ISR really means re-attaching it to the
+           * unexpected exception handler.
+           */
+
            isr = irq_unexpected_isr;
         }