Big, very risky change: Remove all occurrences of up_maskack_irq() that disable and enable interrupts with up_ack_irq() that only acknowledges the interrupts. This is only used in interrupt decoding logic. Also remove the logic that unconditionally re-enables interrupts with the interrupt exits. This interferes with the drivers ability to control the interrupt state. This is a necessary, sweeping, global change and unfortunately impossible to test.

26 files changed, 60 insertions, 198 deletions

diff --git a/nuttx/arch/arm/src/a1x/a1x_irq.c b/nuttx/arch/arm/src/a1x/a1x_irq.c
index bce61765f..1cfa198fd 100644
--- a/nuttx/arch/arm/src/a1x/a1x_irq.c
+++ b/nuttx/arch/arm/src/a1x/a1x_irq.c
@@ -418,25 +418,6 @@ void up_enable_irq(int irq)
 }
 
 /****************************************************************************
- * Name: up_maskack_irq
- *
- * Description:
- *   Mask the IRQ and acknowledge it
- *
- ****************************************************************************/
-
-void up_maskack_irq(int irq)
-{
-  /* Disable the interrupt */
-
-  up_disable_irq(irq);
-
-  /* There is no need to acknowledge the interrupt.  The pending interrupt
-   * was cleared in arm_decodeirq() when the PEND register was read.
-   */
-}
-
-/****************************************************************************
  * Name: up_prioritize_irq
  *
  * Description:
diff --git a/nuttx/arch/arm/src/arm/up_doirq.c b/nuttx/arch/arm/src/arm/up_doirq.c
index 68c4c4022..5a573a23d 100644
--- a/nuttx/arch/arm/src/arm/up_doirq.c
+++ b/nuttx/arch/arm/src/arm/up_doirq.c
@@ -87,9 +87,9 @@ void up_doirq(int irq, uint32_t *regs)
 
   current_regs = regs;
 
-  /* Mask and acknowledge the interrupt */
+  /* Acknowledge the interrupt */
 
-  up_maskack_irq(irq);
+  up_ack_irq(irq);
 
   /* Deliver the IRQ */
 
@@ -128,10 +128,6 @@ void up_doirq(int irq, uint32_t *regs)
    */
 
   current_regs = NULL;
-
-  /* Unmask the last interrupt (global interrupts are still disabled) */
-
-  up_enable_irq(irq);
 #endif
   board_led_off(LED_INIRQ);
 }
diff --git a/nuttx/arch/arm/src/armv7-a/arm_doirq.c b/nuttx/arch/arm/src/armv7-a/arm_doirq.c
index e8661cbec..f66e4ba96 100644
--- a/nuttx/arch/arm/src/armv7-a/arm_doirq.c
+++ b/nuttx/arch/arm/src/armv7-a/arm_doirq.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/arm/src/armv7-a/arm_doirq.c
  *
- *   Copyright (C) 2013-2014 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2013-2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/nuttx/arch/arm/src/c5471/c5471_irq.c b/nuttx/arch/arm/src/c5471/c5471_irq.c
index 7f0f3a668..607a3bb72 100644
--- a/nuttx/arch/arm/src/c5471/c5471_irq.c
+++ b/nuttx/arch/arm/src/c5471/c5471_irq.c
@@ -218,22 +218,17 @@ void up_enable_irq(int irq)
 }
 
 /****************************************************************************
- * Name: up_maskack_irq
+ * Name: up_ack_irq
  *
  * Description:
- *   Mask the IRQ and acknowledge it
+ *   Acknowledge the interrupt
  *
  ****************************************************************************/
 
-void up_maskack_irq(int irq)
+void up_ack_irq(int irq)
 {
   uint32_t reg;
 
-  /* Mask the interrupt */
-
-  reg = getreg32(MASK_IT_REG);
-  putreg32(reg | (1 << irq), MASK_IT_REG);
-
   /* Set the NEW_IRQ_AGR bit.  This clears the IRQ src register
    * enables generation of a new IRQ.
    */
diff --git a/nuttx/arch/arm/src/common/up_internal.h b/nuttx/arch/arm/src/common/up_internal.h
index 9c274dcaf..803276584 100644
--- a/nuttx/arch/arm/src/common/up_internal.h
+++ b/nuttx/arch/arm/src/common/up_internal.h
@@ -354,7 +354,6 @@ int  up_memfault(int irq, FAR void *context);
 
 /* Interrupt acknowledge and dispatch */
 
-void up_maskack_irq(int irq);
 uint32_t *arm_doirq(int irq, uint32_t *regs);
 
 /* Paging support */
@@ -379,7 +378,7 @@ uint32_t *arm_undefinedinsn(uint32_t *regs);
 
 /* Interrupt acknowledge and dispatch */
 
-void up_maskack_irq(int irq);
+void up_ack_irq(int irq);
 void up_doirq(int irq, uint32_t *regs);
 
 /* Paging support (and exception handlers) */
diff --git a/nuttx/arch/arm/src/dm320/dm320_decodeirq.c b/nuttx/arch/arm/src/dm320/dm320_decodeirq.c
index efdade56a..cbb03c5dc 100644
--- a/nuttx/arch/arm/src/dm320/dm320_decodeirq.c
+++ b/nuttx/arch/arm/src/dm320/dm320_decodeirq.c
@@ -94,9 +94,9 @@ void up_decodeirq(uint32_t* regs)
 
       if ((unsigned)irq < NR_IRQS)
         {
-          /* Mask and acknowledge the interrupt */
+          /* Acknowledge the interrupt */
 
-          up_maskack_irq(irq);
+          up_ack_irq(irq);
 
           /* Current regs non-zero indicates that we are processing an interrupt;
            * current_regs is also used to manage interrupt level context switches.
@@ -144,12 +144,6 @@ void up_decodeirq(uint32_t* regs)
            */
 
           current_regs = NULL;
-
-          /* Unmask the last interrupt (global interrupts are still
-           * disabled).
-           */
-
-          up_enable_irq(irq);
         }
     }
 #endif
diff --git a/nuttx/arch/arm/src/dm320/dm320_irq.c b/nuttx/arch/arm/src/dm320/dm320_irq.c
index e909571f3..7d00d18c5 100644
--- a/nuttx/arch/arm/src/dm320/dm320_irq.c
+++ b/nuttx/arch/arm/src/dm320/dm320_irq.c
@@ -201,48 +201,35 @@ void up_enable_irq(int irq)
 }
 
 /************************************************************************
- * Name: up_maskack_irq
+ * Name: up_ack_irq
  *
  * Description:
- *   Mask the IRQ and acknowledge it
+ *   Acknowledge the interupt
  *
  ************************************************************************/
 
-void up_maskack_irq(int irq)
+void up_ack_irq(int irq)
 {
-  /* Disable the interrupt by clearing the corresponding bit in
-   * the IRQ enable register.  And acknowlege it by setting the
-   * corresponding bit in the IRQ status register.
+  /* Acknowlege the interrupt by setting the corresponding bit in the
+   * IRQ status register.
    */
 
   if (irq < 16)
     {
-      /* IRQs0-15 are controlled by the IRQ0 enable register
-       * Clear the associated enable bit to disable the interrupt
-       * Set the associated status bit to clear the interrupt
-       */
+      /* Set the associated status bit to clear the interrupt */
 
-      putreg16((getreg16(DM320_INTC_EINT0) & ~(1<< irq)), DM320_INTC_EINT0);
       putreg16((1 << irq), DM320_INTC_IRQ0);
     }
   else if (irq < 32)
     {
-      /* IRQs16-31 are controlled by the IRQ1 enable register
-       * Clear the associated enable bit to disable the interrupt
-       * Set the associated status bit to clear the interrupt
-       */
+      /* Set the associated status bit to clear the interrupt  */
 
-      putreg16((getreg16(DM320_INTC_EINT1) & ~(1<< (irq-16))), DM320_INTC_EINT1);
       putreg16((1 << (irq-16)), DM320_INTC_IRQ1);
     }
   else
     {
-      /* IRQs32- are controlled by the IRQ2 enable register
-       * Clear the associated enable bit to disable the interrupt
-       * Set the associated status bit to clear the interrupt
-       */
+      /* Set the associated status bit to clear the interrupt */
 
-      putreg16((getreg16(DM320_INTC_EINT2) & ~(1<< (irq-32))), DM320_INTC_EINT2);
       putreg16((1 << (irq-32)), DM320_INTC_IRQ2);
     }
 }
diff --git a/nuttx/arch/arm/src/dm320/dm320_usbdev.c b/nuttx/arch/arm/src/dm320/dm320_usbdev.c
index 68ca40957..a8fe80d12 100644
--- a/nuttx/arch/arm/src/dm320/dm320_usbdev.c
+++ b/nuttx/arch/arm/src/dm320/dm320_usbdev.c
@@ -1824,8 +1824,8 @@ static void dm320_ctrlinitialize(FAR struct dm320_usbdev_s *priv)
 
   /* Initialize interrupts *****************************************************/
 
-  up_maskack_irq(DM320_IRQ_USB0);      /* Clear USB controller interrupt */
-  up_maskack_irq(DM320_IRQ_USB1);      /* Clear USB DMA interrupt flag */
+  up_ack_irq(DM320_IRQ_USB0);                /* Clear USB controller interrupt */
+  up_ack_irq(DM320_IRQ_USB1);                /* Clear USB DMA interrupt flag */
 
   dm320_getreg8(DM320_USB_INTRTX1);          /* Clear TX interrupt */
   dm320_getreg8(DM320_USB_INTRRX1);          /* Clear RX interrupt */
diff --git a/nuttx/arch/arm/src/imx/imx_decodeirq.c b/nuttx/arch/arm/src/imx/imx_decodeirq.c
index 4e7c4e653..9619792b6 100644
--- a/nuttx/arch/arm/src/imx/imx_decodeirq.c
+++ b/nuttx/arch/arm/src/imx/imx_decodeirq.c
@@ -110,10 +110,6 @@ void up_decodeirq(uint32_t* regs)
 
       if (irq < NR_IRQS)
         {
-          /* Mask and acknowledge the interrupt */
-
-          up_maskack_irq(irq);
-
           /* Deliver the IRQ */
 
           irq_dispatch(irq, regs);
@@ -145,11 +141,6 @@ void up_decodeirq(uint32_t* regs)
 #endif
             }
 #endif
-          /* Unmask the last interrupt (global interrupts are still
-           * disabled).
-           */
-
-          up_enable_irq(irq);
         }
     }
   while (irq < NR_IRQS);
diff --git a/nuttx/arch/arm/src/imx/imx_irq.c b/nuttx/arch/arm/src/imx/imx_irq.c
index 9e0fe124f..fbecd098c 100644
--- a/nuttx/arch/arm/src/imx/imx_irq.c
+++ b/nuttx/arch/arm/src/imx/imx_irq.c
@@ -129,16 +129,3 @@ void up_enable_irq(int irq)
 {
   putreg32(irq, IMX_AITC_INTENNUM);
 }
-
-/****************************************************************************
- * Name: up_maskack_irq
- *
- * Description:
- *   Mask the IRQ and acknowledge it
- *
- ****************************************************************************/
-
-void up_maskack_irq(int irq)
-{
-  up_disable_irq(irq);
-}
diff --git a/nuttx/arch/arm/src/lpc2378/lpc23xx_decodeirq.c b/nuttx/arch/arm/src/lpc2378/lpc23xx_decodeirq.c
index 009414e92..57334f7b9 100644
--- a/nuttx/arch/arm/src/lpc2378/lpc23xx_decodeirq.c
+++ b/nuttx/arch/arm/src/lpc2378/lpc23xx_decodeirq.c
@@ -139,9 +139,9 @@ static void lpc23xx_decodeirq(uint32_t *regs)
       savestate    = (uint32_t*)current_regs;
       current_regs = regs;
 
-      /* Mask and acknowledge the interrupt */
+      /* Acknowledge the interrupt */
 
-      up_maskack_irq(irq);
+      up_ack_irq(irq);
 
       /* Deliver the IRQ */
 
@@ -163,13 +163,15 @@ void up_decodeirq(uint32_t *regs)
 {
   vic_vector_t vector = (vic_vector_t) vic_getreg(VIC_ADDRESS_OFFSET);
 
-  /* Mask and acknowledge the interrupt */
+  /* Acknowledge the interrupt */
 
-  up_maskack_irq(irq);
+  up_ack_irq(irq);
 
   /* Valid Interrupt */
 
   if (vector != NULL)
-    (vector) (regs);
+    {
+      (vector)(regs);
+    }
 }
 #endif
diff --git a/nuttx/arch/arm/src/lpc2378/lpc23xx_irq.c b/nuttx/arch/arm/src/lpc2378/lpc23xx_irq.c
index 5274ee4ee..0be33877e 100644
--- a/nuttx/arch/arm/src/lpc2378/lpc23xx_irq.c
+++ b/nuttx/arch/arm/src/lpc2378/lpc23xx_irq.c
@@ -190,14 +190,14 @@ void up_enable_irq(int irq)
 }
 
 /****************************************************************************
- * Name: up_maskack_irq
+ * Name: up_ack_irq
  *
  * Description:
- *   Mask the IRQ and acknowledge it
+ *   Acknowledge the interrupt
  *
  ****************************************************************************/
 
-void up_maskack_irq(int irq)
+void up_ack_irq(int irq)
 {
   uint32_t reg32;
 
diff --git a/nuttx/arch/arm/src/lpc31xx/lpc31_decodeirq.c b/nuttx/arch/arm/src/lpc31xx/lpc31_decodeirq.c
index 1a29da818..8401fc75a 100644
--- a/nuttx/arch/arm/src/lpc31xx/lpc31_decodeirq.c
+++ b/nuttx/arch/arm/src/lpc31xx/lpc31_decodeirq.c
@@ -101,9 +101,9 @@ void up_decodeirq(uint32_t *regs)
 
       if ((unsigned)irq < NR_IRQS)
         {
-          /* Mask and acknowledge the interrupt */
+          /* Acknowledge the interrupt */
 
-          up_maskack_irq(irq);
+          up_ack_irq(irq);
 
           /* Current regs non-zero indicates that we are processing an interrupt;
            * current_regs is also used to manage interrupt level context switches.
@@ -150,12 +150,6 @@ void up_decodeirq(uint32_t *regs)
            */
 
           current_regs = NULL;
-
-          /* Unmask the last interrupt (global interrupts are still
-           * disabled).
-           */
-
-          up_enable_irq(irq);
         }
     }
 #endif
diff --git a/nuttx/arch/arm/src/lpc31xx/lpc31_irq.c b/nuttx/arch/arm/src/lpc31xx/lpc31_irq.c
index 6a992c69f..1e246b725 100644
--- a/nuttx/arch/arm/src/lpc31xx/lpc31_irq.c
+++ b/nuttx/arch/arm/src/lpc31xx/lpc31_irq.c
@@ -174,14 +174,14 @@ void up_enable_irq(int irq)
 }
 
 /****************************************************************************
- * Name: up_maskack_irq
+ * Name: up_ack_irq
  *
  * Description:
- *   Mask the IRQ and acknowledge it
+ *   Acknowledge the interrupt
  *
  ****************************************************************************/
 
-void up_maskack_irq(int irq)
+void up_ack_irq(int irq)
 {
   /* Get the address of the request register corresponding to this
    * interrupt source
@@ -189,12 +189,13 @@ void up_maskack_irq(int irq)
 
   uint32_t address = LPC31_INTC_REQUEST(irq+1);
 
-  /* Clear the pending interrupt (INTC_REQUEST_CLRSWINT=1) AND disable interrupts
-   * (ENABLE=0 && WE_ENABLE=1). Configuration settings will be preserved because
-   * WE_TARGET is zero.
+  /* Clear the pending interrupt (INTC_REQUEST_CLRSWINT=1) while keeping
+   * interrupts enabled (ENABLE=1 && WE_ENABLE=1). Configuration settings
+   * will be preserved because WE_TARGET is zero.
    */
 
-  putreg32(INTC_REQUEST_CLRSWINT|INTC_REQUEST_WEENABLE, address);
+  putreg32(INTC_REQUEST_CLRSWINT|INTC_REQUEST_ENABLE|INTC_REQUEST_WEENABLE,
+           address);
 }
 
 /****************************************************************************
diff --git a/nuttx/arch/arm/src/sama5/sam_irq.c b/nuttx/arch/arm/src/sama5/sam_irq.c
index 8c39503ab..3c8b03273 100644
--- a/nuttx/arch/arm/src/sama5/sam_irq.c
+++ b/nuttx/arch/arm/src/sama5/sam_irq.c
@@ -785,19 +785,6 @@ void up_enable_irq(int irq)
 }
 
 /****************************************************************************
- * Name: up_maskack_irq
- *
- * Description:
- *   Mask the IRQ and acknowledge it
- *
- ****************************************************************************/
-
-void up_maskack_irq(int irq)
-{
-  up_disable_irq(irq);
-}
-
-/****************************************************************************
  * Name: up_prioritize_irq (and sam_prioritize_irq helper)
  *
  * Description:
diff --git a/nuttx/arch/arm/src/str71x/str71x_decodeirq.c b/nuttx/arch/arm/src/str71x/str71x_decodeirq.c
index 6e9c9f738..a7b883188 100644
--- a/nuttx/arch/arm/src/str71x/str71x_decodeirq.c
+++ b/nuttx/arch/arm/src/str71x/str71x_decodeirq.c
@@ -116,9 +116,9 @@ void up_decodeirq(uint32_t *regs)
       savestate     = (uint32_t*)current_regs;
       current_regs = regs;
 
-      /* Mask and acknowledge the interrupt */
+      /* Acknowledge the interrupt */
 
-      up_maskack_irq(irq);
+      up_ack_irq(irq);
 
       /* Deliver the IRQ */
 
@@ -130,10 +130,6 @@ void up_decodeirq(uint32_t *regs)
        */
 
       current_regs = savestate;
-
-      /* Unmask the last interrupt (global interrupts are still disabled) */
-
-      up_enable_irq(irq);
     }
 #if CONFIG_DEBUG
   else
diff --git a/nuttx/arch/arm/src/str71x/str71x_irq.c b/nuttx/arch/arm/src/str71x/str71x_irq.c
index 98d5e9f63..7589bd0b3 100644
--- a/nuttx/arch/arm/src/str71x/str71x_irq.c
+++ b/nuttx/arch/arm/src/str71x/str71x_irq.c
@@ -169,26 +169,20 @@ void up_enable_irq(int irq)
 }
 
 /****************************************************************************
- * Name: up_maskack_irq
+ * Name: up_ack_irq
  *
  * Description:
- *   Mask the IRQ and acknowledge it.  No XTI support.. only used in
- *   interrupt handling logic.
+ *   Acknowledge the interrupt.  No XTI support.. only used in interrupt
+ *   handling logic.
  *
  ****************************************************************************/
 
-void up_maskack_irq(int irq)
+void up_ack_irq(int irq)
 {
   uint32_t reg32;
 
   if ((unsigned)irq < STR71X_NBASEIRQS)
     {
-      /* Mask the IRQ by clearing the associated bit in the IER register */
-
-      reg32  = getreg32(STR71X_EIC_IER);
-      reg32 &= ~(1 << irq);
-      putreg32(reg32, STR71X_EIC_IER);
-
       /* Clear the interrupt by writing a one to the corresponding bit in the
        * IPR register.
        */
diff --git a/nuttx/arch/hc/src/common/up_internal.h b/nuttx/arch/hc/src/common/up_internal.h
index ffaf09380..e774892fc 100644
--- a/nuttx/arch/hc/src/common/up_internal.h
+++ b/nuttx/arch/hc/src/common/up_internal.h
@@ -173,7 +173,6 @@ extern void up_switchcontext(uint8_t *saveregs, uint8_t *restoreregs);
 /* Interrupt handling */
 
 extern uint8_t *up_doirq(int irq, uint8_t *regs);
-extern void up_maskack_irq(int irq);
 
 /* Signal handling */
 
diff --git a/nuttx/arch/sh/src/common/up_doirq.c b/nuttx/arch/sh/src/common/up_doirq.c
index ec165dcd0..2c8559b05 100644
--- a/nuttx/arch/sh/src/common/up_doirq.c
+++ b/nuttx/arch/sh/src/common/up_doirq.c
@@ -88,12 +88,6 @@ uint32_t *up_doirq(int irq, uint32_t* regs)
       DEBUGASSERT(current_regs == NULL);
       current_regs = regs;
 
-      /* Mask and acknowledge the interrupt (if supported by the chip) */
-
-#ifndef CONFIG_ARCH_NOINTC
-      up_maskack_irq(irq);
-#endif
-
       /* Deliver the IRQ */
 
       irq_dispatch(irq, regs);
@@ -136,14 +130,6 @@ uint32_t *up_doirq(int irq, uint32_t* regs)
        */
 
       current_regs = NULL;
-
-      /* Unmask the last interrupt (global interrupts are still
-       * disabled.
-       */
-
-#ifndef CONFIG_ARCH_NOINTC
-      up_enable_irq(irq);
-#endif
     }
 
   board_led_off(LED_INIRQ);
diff --git a/nuttx/arch/sh/src/common/up_internal.h b/nuttx/arch/sh/src/common/up_internal.h
index 180f6cebe..c7f831647 100644
--- a/nuttx/arch/sh/src/common/up_internal.h
+++ b/nuttx/arch/sh/src/common/up_internal.h
@@ -208,14 +208,6 @@ extern void up_wdtinit(void);
 
 extern void up_timer_initialize(void);
 
-/* Defined in chip-specific logic if CONFIG_ARCH_NOINTC is not set */
-
-#ifndef CONFIG_ARCH_NOINTC
-extern void up_maskack_irq(int irq);
-#else
-#  define up_maskack_irq(irq)
-#endif
-
 /* Defined in board/up_leds.c */
 
 #ifdef CONFIG_ARCH_LEDS
diff --git a/nuttx/arch/x86/src/common/up_internal.h b/nuttx/arch/x86/src/common/up_internal.h
index 56d5e6510..98df42670 100644
--- a/nuttx/arch/x86/src/common/up_internal.h
+++ b/nuttx/arch/x86/src/common/up_internal.h
@@ -234,10 +234,6 @@ extern void up_wdtinit(void);
 
 extern void up_timer_initialize(void);
 
-/* Defined in up_irq.c */
-
-extern void up_maskack_irq(int irq);
-
 /* Defined in board/up_leds.c */
 
 #ifdef CONFIG_ARCH_LEDS
diff --git a/nuttx/arch/z16/src/common/up_doirq.c b/nuttx/arch/z16/src/common/up_doirq.c
index 7e9a3fd9f..38290a47a 100644
--- a/nuttx/arch/z16/src/common/up_doirq.c
+++ b/nuttx/arch/z16/src/common/up_doirq.c
@@ -106,9 +106,9 @@ FAR chipreg_t *up_doirq(int irq, FAR chipreg_t *regs)
       savestate    = (FAR chipreg_t *)current_regs;
       current_regs = regs;
 
-      /* Mask and acknowledge the interrupt */
+      /* Acknowledge the interrupt */
 
-      up_maskack_irq(irq);
+      up_ack_irq(irq);
 
       /* Deliver the IRQ */
 
@@ -121,12 +121,6 @@ FAR chipreg_t *up_doirq(int irq, FAR chipreg_t *regs)
 
       ret          = current_regs;
       current_regs = savestate;
-
-      /* Unmask the last interrupt (global interrupts are still
-       * disabled.
-       */
-
-      up_enable_irq(irq);
     }
 
   board_led_off(LED_INIRQ);
diff --git a/nuttx/arch/z16/src/common/up_internal.h b/nuttx/arch/z16/src/common/up_internal.h
index f76b970e3..608ca296f 100644
--- a/nuttx/arch/z16/src/common/up_internal.h
+++ b/nuttx/arch/z16/src/common/up_internal.h
@@ -180,7 +180,7 @@ extern void up_timer_initialize(void);
 
 /* Defined in up_irq.c */
 
-extern void up_maskack_irq(int irq);
+extern void up_ack_irq(int irq);
 
 /* Defined in board/up_leds.c */
 
diff --git a/nuttx/arch/z16/src/z16f/z16f_irq.c b/nuttx/arch/z16/src/z16f/z16f_irq.c
index 317ec4a6f..e0f14d75d 100644
--- a/nuttx/arch/z16/src/z16f/z16f_irq.c
+++ b/nuttx/arch/z16/src/z16f/z16f_irq.c
@@ -164,37 +164,33 @@ void up_enable_irq(int irq)
 }
 
 /****************************************************************************
- * Name: up_maskack_irq
+ * Name: up_ack_irq
  *
  * Description:
- *   Mask the IRQ and acknowledge it
+ *   Acknowledge the interrupt
  *
  ****************************************************************************/
 
-void up_maskack_irq(int irq)
+void up_ack_irq(int irq)
 {
   /* System exceptions cannot be disabled or acknowledged */
 
   if (irq >= Z16F_IRQ_IRQ0)
     {
-      /* Disable the interrupt by clearing the corresponding bit in the
-       * appropriate IRQ enable register and acknowledge it by setting the
-       * corresponding bit in the IRQ status register.
+      /* Acknowledge the interrupt by setting the corresponding bit in the
+       * IRQ status register.
        */
 
       if (irq < Z16F_IRQ_IRQ1)
         {
-           putreg8((getreg8(Z16F_IRQ0_ENH) & ~Z16F_IRQ0_BIT(irq)), Z16F_IRQ0_ENH);
            putreg8(Z16F_IRQ0_BIT(irq), Z16F_IRQ0);
         }
       else if (irq < Z16F_IRQ_IRQ2)
         {
-           putreg8((getreg8(Z16F_IRQ1_ENH) & ~Z16F_IRQ1_BIT(irq)), Z16F_IRQ1_ENH);
            putreg8(Z16F_IRQ1_BIT(irq), Z16F_IRQ2);
         }
       else if (irq < NR_IRQS)
         {
-           putreg8((getreg8(Z16F_IRQ2_ENH) & ~Z16F_IRQ2_BIT(irq)), Z16F_IRQ2_ENH);
            putreg8(Z16F_IRQ2_BIT(irq), Z16F_IRQ2);
         }
     }
diff --git a/nuttx/arch/z80/src/z8/switch.h b/nuttx/arch/z80/src/z8/switch.h
index 3e4a4d28e..495530e83 100644
--- a/nuttx/arch/z80/src/z8/switch.h
+++ b/nuttx/arch/z80/src/z8/switch.h
@@ -130,7 +130,7 @@
     savestate.regs     = g_z8irqstate.regs; \
     g_z8irqstate.state = Z8_IRQSTATE_ENTRY; \
     g_z8irqstate.regs  = (regs); \
-    up_maskack_irq(irq); \
+    up_ack_irq(irq); \
   } while (0)
 
 /* The following macro is used when the system exits interrupt handling logic */
@@ -139,7 +139,6 @@
   do { \
     g_z8irqstate.state = savestate.state; \
     g_z8irqstate.regs  = savestate.regs; \
-    up_enable_irq(irq); \
   } while (0)
 
 /* The following macro is used to sample the interrupt state (as a opaque handle) */
@@ -229,7 +228,7 @@ extern "C"
 
 /* Defined in z8_irq.c */
 
-void up_maskack_irq(int irq);
+void up_ack_irq(int irq);
 
 /* Defined in z8_saveusercontext.asm */
 
diff --git a/nuttx/arch/z80/src/z8/z8_irq.c b/nuttx/arch/z80/src/z8/z8_irq.c
index 82ab4d60c..c1c65ff65 100644
--- a/nuttx/arch/z80/src/z8/z8_irq.c
+++ b/nuttx/arch/z80/src/z8/z8_irq.c
@@ -211,37 +211,33 @@ void up_enable_irq(int irq)
 }
 
 /****************************************************************************
- * Name: up_maskack_irq
+ * Name: up_ack_irq
  *
  * Description:
- *   Mask the IRQ and acknowledge it
+ *   Acknowledge the interrupt
  *
  ****************************************************************************/
 
-void up_maskack_irq(int irq)
+void up_ack_irq(int irq)
 {
   /* System exceptions cannot be disabled or acknowledged */
 
   if (irq >= Z8_IRQ0_MIN)
     {
-      /* Disable the interrupt by clearing the corresponding bit in the
-       * appropriate IRQ enable register and acknowledge it by setting the
-       * corresponding bit in the IRQ status register.
+      /* Acknowledge the interrupt by setting the* corresponding bit in the
+       * IRQ status register.
        */
 
       if (irq <= Z8_IRQ0_MAX)
         {
-           putreg8((getreg8(IRQ0ENH) & ~Z8_IRQ0_BIT(irq)), IRQ0ENH);
            putreg8(Z8_IRQ0_BIT(irq), IRQ0);
         }
       else if (irq <= Z8_IRQ1_MAX)
         {
-           putreg8((getreg8(IRQ1ENH) & ~Z8_IRQ1_BIT(irq)), IRQ1ENH);
            putreg8(Z8_IRQ1_BIT(irq), IRQ2);
         }
       else if (irq < NR_IRQS)
         {
-           putreg8((getreg8(IRQ2ENH) & ~Z8_IRQ2_BIT(irq)), IRQ2ENH);
            putreg8(Z8_IRQ2_BIT(irq), IRQ2);
         }
     }