diff --git a/arch/arm/src/sam34/sam3u_gpio.c b/arch/arm/src/sam34/sam3u_gpio.c
index d94f2a3f86..abaec84daa 100644
--- a/arch/arm/src/sam34/sam3u_gpio.c
+++ b/arch/arm/src/sam34/sam3u_gpio.c
@@ -375,11 +375,14 @@ int sam_configgpio(gpio_pinset_t cfgset)
 {
   uintptr_t base = sam_gpiobase(cfgset);
   uint32_t  pin  = sam_gpiopin(cfgset);
+  irqstate_t flags;
   int       ret;
 
-  /* Enable writing to GPIO registers
-   * TODO:  This probably requires some protection against re-entry.
-   */
+  /* Disable interrupts to prohibit re-entrance. */
+
+  flags = irqsave();
+
+  /* Enable writing to GPIO registers */
 
   putreg32(PIO_WPMR_WPKEY, base + SAM_PIO_WPMR_OFFSET);
 
@@ -409,9 +412,10 @@ int sam_configgpio(gpio_pinset_t cfgset)
         break;
     }
 
-  /* Enable writing to GPIO registers */
+  /* Disable writing to GPIO registers */
 
   putreg32(PIO_WPMR_WPEN | PIO_WPMR_WPKEY, base + SAM_PIO_WPMR_OFFSET);
+  irqrestore(flags);
 
   return ret;
 }
diff --git a/arch/arm/src/sam34/sam_gpioirq.c b/arch/arm/src/sam34/sam_gpioirq.c
index 3b7c8a2a29..399a3eb191 100644
--- a/arch/arm/src/sam34/sam_gpioirq.c
+++ b/arch/arm/src/sam34/sam_gpioirq.c
@@ -169,14 +169,14 @@ static int sam_irqbase(int irq, uint32_t *base, int *pin)
 }
 
 /****************************************************************************
- * Name: up_gpioa/b/cinterrupt
+ * Name: sam_gpioa/b/cinterrupt
  *
  * Description:
  *   Receive GPIOA/B/C interrupts
  *
  ****************************************************************************/
 
-static int up_gpiointerrupt(uint32_t base, int irq0, void *context)
+static int sam_gpiointerrupt(uint32_t base, int irq0, void *context)
 {
   uint32_t pending;
   uint32_t bit;
@@ -200,44 +200,44 @@ static int up_gpiointerrupt(uint32_t base, int irq0, void *context)
 }
 
 #ifdef CONFIG_GPIOA_IRQ
-static int up_gpioainterrupt(int irq, void *context)
+static int sam_gpioainterrupt(int irq, void *context)
 {
-  return up_gpiointerrupt(SAM_PIOA_BASE, SAM_IRQ_PA0, context);
+  return sam_gpiointerrupt(SAM_PIOA_BASE, SAM_IRQ_PA0, context);
 }
 #endif
 
 #ifdef CONFIG_GPIOB_IRQ
-static int up_gpiobinterrupt(int irq, void *context)
+static int sam_gpiobinterrupt(int irq, void *context)
 {
-  return up_gpiointerrupt(SAM_PIOB_BASE, SAM_IRQ_PB0, context);
+  return sam_gpiointerrupt(SAM_PIOB_BASE, SAM_IRQ_PB0, context);
 }
 #endif
 
 #ifdef CONFIG_GPIOC_IRQ
-static int up_gpiocinterrupt(int irq, void *context)
+static int sam_gpiocinterrupt(int irq, void *context)
 {
-  return up_gpiointerrupt(SAM_PIOC_BASE, SAM_IRQ_PC0, context);
+  return sam_gpiointerrupt(SAM_PIOC_BASE, SAM_IRQ_PC0, context);
 }
 #endif
 
 #ifdef CONFIG_GPIOD_IRQ
-static int up_gpiodinterrupt(int irq, void *context)
+static int sam_gpiodinterrupt(int irq, void *context)
 {
-  return up_gpiointerrupt(SAM_PIOD_BASE, SAM_IRQ_PD0, context);
+  return sam_gpiointerrupt(SAM_PIOD_BASE, SAM_IRQ_PD0, context);
 }
 #endif
 
 #ifdef CONFIG_GPIOE_IRQ
-static int up_gpioeinterrupt(int irq, void *context)
+static int sam_gpioeinterrupt(int irq, void *context)
 {
-  return up_gpiointerrupt(SAM_PIOE_BASE, SAM_IRQ_PE0, context);
+  return sam_gpiointerrupt(SAM_PIOE_BASE, SAM_IRQ_PE0, context);
 }
 #endif
 
 #ifdef CONFIG_GPIOF_IRQ
-static int up_gpiofinterrupt(int irq, void *context)
+static int sam_gpiofinterrupt(int irq, void *context)
 {
-  return up_gpiointerrupt(SAM_PIOF_BASE, SAM_IRQ_PF0, context);
+  return sam_gpiointerrupt(SAM_PIOF_BASE, SAM_IRQ_PF0, context);
 }
 #endif
 
@@ -270,7 +270,7 @@ void sam_gpioirqinitialize(void)
 
   /* Attach and enable the GPIOA IRQ */
 
-  (void)irq_attach(SAM_IRQ_PIOA, up_gpioainterrupt);
+  (void)irq_attach(SAM_IRQ_PIOA, sam_gpioainterrupt);
   up_enable_irq(SAM_IRQ_PIOA);
 #endif
 
@@ -288,7 +288,7 @@ void sam_gpioirqinitialize(void)
 
   /* Attach and enable the GPIOB IRQ */
 
-  (void)irq_attach(SAM_IRQ_PIOB, up_gpiobinterrupt);
+  (void)irq_attach(SAM_IRQ_PIOB, sam_gpiobinterrupt);
   up_enable_irq(SAM_IRQ_PIOB);
 #endif
 
@@ -306,7 +306,7 @@ void sam_gpioirqinitialize(void)
 
   /* Attach and enable the GPIOC IRQ */
 
-  (void)irq_attach(SAM_IRQ_PIOC, up_gpiocinterrupt);
+  (void)irq_attach(SAM_IRQ_PIOC, sam_gpiocinterrupt);
   up_enable_irq(SAM_IRQ_PIOC);
 #endif
 
@@ -324,7 +324,7 @@ void sam_gpioirqinitialize(void)
 
   /* Attach and enable the GPIOC IRQ */
 
-  (void)irq_attach(SAM_IRQ_PIOD, up_gpiodinterrupt);
+  (void)irq_attach(SAM_IRQ_PIOD, sam_gpiodinterrupt);
   up_enable_irq(SAM_IRQ_PIOD);
 #endif
 
@@ -342,7 +342,7 @@ void sam_gpioirqinitialize(void)
 
   /* Attach and enable the GPIOE IRQ */
 
-  (void)irq_attach(SAM_IRQ_PIOE, up_gpioeinterrupt);
+  (void)irq_attach(SAM_IRQ_PIOE, sam_gpioeinterrupt);
   up_enable_irq(SAM_IRQ_PIOE);
 #endif
 
@@ -360,7 +360,7 @@ void sam_gpioirqinitialize(void)
 
   /* Attach and enable the GPIOF IRQ */
 
-  (void)irq_attach(SAM_IRQ_PIOF, up_gpiofinterrupt);
+  (void)irq_attach(SAM_IRQ_PIOF, sam_gpiofinterrupt);
   up_enable_irq(SAM_IRQ_PIOF);
 #endif
 }