diff --git a/drivers/ioexpander/tca64xx.c b/drivers/ioexpander/tca64xx.c
index e882bf26d25..3a9922721bc 100644
--- a/drivers/ioexpander/tca64xx.c
+++ b/drivers/ioexpander/tca64xx.c
@@ -919,7 +919,7 @@ static int tca64_multireadpin(FAR struct ioexpander_dev_s *dev,
 #ifdef CONFIG_TCA64XX_INT_ENABLE
   /* Update the input status with the 32 bits read from the expander */
 
-  tca64_int_update(priv, pinset, ~0);
+  tca64_int_update(priv, pinset, PINSET_ALL);
 #endif
 
 errout_with_lock:
@@ -971,11 +971,10 @@ static int tca64_attach(FAR struct ioexpander_dev_s *dev, ioe_pinset_t pinset,
            priv->cb[i].pinset = pinset;
            priv->cb[i].cbfunc = callback;
            ret = OK;
+           break;
          }
     }
 
-  /* Add this callback to the table */
-
   tca64_unlock(priv);
   return ret;
 }
@@ -1003,10 +1002,12 @@ static void tca64_int_update(void *handle, ioe_pinset_t input,
   /* Check the changed bits from last read */
 
   input = (priv->input & ~mask) | (input & mask);
-  diff = priv->input ^ input;
+  diff  = priv->input ^ input;
 
-  if (!diff)
+  if (diff == 0)
     {
+      /* Nothing has changed */
+
       leave_critical_section(flags);
       return;
     }
@@ -1031,7 +1032,7 @@ static void tca64_int_update(void *handle, ioe_pinset_t input,
         {
           /* Level triggered. Set intstat if in match level type. */
 
-          if (((input & 1) != 0 &&  TCA64_LEVEL_HIGH(priv, pin)) ||
+          if (((input & 1) != 0 && TCA64_LEVEL_HIGH(priv, pin)) ||
               ((input & 1) == 0 && TCA64_LEVEL_LOW(priv, pin)))
             {
               priv->intstat |= 1 << pin;
@@ -1093,7 +1094,7 @@ static void tca64_register_update(FAR struct tca64_dev_s *priv)
 
   /* Update the input status with the 32 bits read from the expander */
 
-  tca64_int_update(priv, pinset, ~0);
+  tca64_int_update(priv, pinset, PINSET_ALL);
 }
 #endif
 
@@ -1119,6 +1120,10 @@ static void tca64_irqworker(void *arg)
 
   DEBUGASSERT(priv != NULL && priv->config != NULL);
 
+  /* Get exclusive access to read inputs and assess pending interrupts. */
+
+  tca64_lock(priv);
+
   /* Read the input register for pin 0 through the number of supported pins.
    *
    * The Input Port Register reflects the incoming logic levels of the pins,
@@ -1136,26 +1141,31 @@ static void tca64_irqworker(void *arg)
     {
       gpioerr("ERROR: Failed to read input %u registers at %u: %d\n",
               nregs, regaddr, ret);
-      return;
+      tca64_unlock(priv);
+      goto errout_with_restart;
     }
 
   /* Update the input status with the 32 bits read from the expander */
 
-  tca64_int_update(priv, pinset, ~0);
+  tca64_int_update(priv, pinset, PINSET_ALL);
+
+  /* Sample and clear the pending interrupts.  */
+
+  pinset        = priv->intstat;
+  priv->intstat = 0;
+  tca64_unlock(priv);
 
   /* Perform pin interrupt callbacks */
 
   for (i = 0; i < CONFIG_TCA64XX_INT_NCALLBACKS; i++)
     {
-      /* Is this entry valid (i.e., callback attached)?  If so, did andy of
-       * the requested pin interrupts occur?
-       */
+      /* Is this entry valid (i.e., callback attached)?  */
 
       if (priv->cb[i].cbfunc != NULL)
         {
           /* Did any of the requested pin interrupts occur? */
 
-          ioe_pinset_t match = priv->intstat & priv->cb[i].pinset;
+          ioe_pinset_t match = pinset & priv->cb[i].pinset;
           if (match != 0)
             {
               /* Yes.. perform the callback */
@@ -1165,7 +1175,7 @@ static void tca64_irqworker(void *arg)
         }
     }
 
-  priv->intstat = 0;
+errout_with_restart:
 
 #ifdef CONFIG_TCA64XX_INT_POLL
   /* Check for pending interrupts */
@@ -1332,6 +1342,12 @@ FAR struct ioexpander_dev_s *tca64_initialize(FAR struct i2c_master_s *i2c,
   priv->config  = config;
 
 #ifdef CONFIG_TCA64XX_INT_ENABLE
+  /* Initial interrupt state:  Edge triggered on both edges */
+
+  priv->trigger  = PINSET_ALL;  /* All edge triggered */
+  priv->level[0] = PINSET_ALL;  /* All rising edge */
+  priv->level[1] = PINSET_ALL;  /* All falling edge */
+
 #ifdef CONFIG_TCA64XX_INT_POLL
   /* Set up a timer to poll for missed interrupts */
 
diff --git a/drivers/ioexpander/tca64xx.h b/drivers/ioexpander/tca64xx.h
index b1dd69118bc..704fbc8c81b 100644
--- a/drivers/ioexpander/tca64xx.h
+++ b/drivers/ioexpander/tca64xx.h
@@ -192,18 +192,18 @@
 #define TCA64XX_POLLDELAY       (CONFIG_TCA64XX_INT_POLLDELAY / USEC_PER_TICK)
 
 #define TCA64_LEVEL_SENSITIVE(d,p) \
-  (((d)->trigger & (1 << (p))) == 0)
+  (((d)->trigger  & ((ioe_pinset_t)1 << (p))) == 0)
 #define TCA64_LEVEL_HIGH(d,p) \
-  (((d)->level[0] & (1 << (p))) != 0)
+  (((d)->level[0] & ((ioe_pinset_t)1 << (p))) != 0)
 #define TCA64_LEVEL_LOW(d,p) \
-  (((d)->level[1] & (1 << (p))) != 0)
+  (((d)->level[1] & ((ioe_pinset_t)1 << (p))) != 0)
 
 #define TCA64_EDGE_SENSITIVE(d,p) \
-  (((d)->trigger & (1 << (p))) != 0)
+  (((d)->trigger  & ((ioe_pinset_t)1 << (p))) != 0)
 #define TCA64_EDGE_RISING(d,p) \
-  (((d)->level[0] & (1 << (p))) != 0)
+  (((d)->level[0] & ((ioe_pinset_t)1 << (p))) != 0)
 #define TCA64_EDGE_FALLING(d,p) \
-  (((d)->level[1] & (1 << (p))) != 0)
+  (((d)->level[1] & ((ioe_pinset_t)1 << (p))) != 0)
 #define TCA64_EDGE_BOTH(d,p) \
   (TCA64_LEVEL_RISING(d,p) && TCA64_LEVEL_FALLING(d,p))
 
@@ -246,11 +246,11 @@ struct tca64_dev_s
   uint8_t addr;                      /* TCA64xx I2C address */
   sem_t exclsem;                     /* Mutual exclusion */
 
+#ifdef CONFIG_IOEXPANDER_INT_ENABLE
 #ifdef CONFIG_TCA64XX_INT_POLL
   WDOG_ID wdog;                      /* Timer used to poll for missed interrupts */
 #endif
 
-#ifdef CONFIG_IOEXPANDER_INT_ENABLE
   ioe_pinset_t input;                /* Last input registeres */
   ioe_pinset_t intstat;              /* Pending interrupts */
   ioe_pinset_t trigger;              /* Bit encoded: 0=level 1=edge */
diff --git a/include/nuttx/ioexpander/ioexpander.h b/include/nuttx/ioexpander/ioexpander.h
index e844d984da6..6557f9f7bec 100644
--- a/include/nuttx/ioexpander/ioexpander.h
+++ b/include/nuttx/ioexpander/ioexpander.h
@@ -66,17 +66,19 @@
 
 /* Pin options */
 
-#define IOEXPANDER_OPTION_INVERT 1        /* Set the "active" level for a pin */
-#  define IOEXPANDER_VAL_NORMAL  0        /* Normal, no inversion */
-#  define IOEXPANDER_VAL_INVERT  1        /* Inverted */
+#define IOEXPANDER_OPTION_INVERT 1  /* Set the "active" level for a pin */
+#  define IOEXPANDER_VAL_NORMAL  0  /* Normal, no inversion */
+#  define IOEXPANDER_VAL_INVERT  1  /* Inverted */
 
-#define IOEXPANDER_OPTION_INTCFG 2        /* Configure interrupt for a pin */
-#  define IOEXPANDER_VAL_LEVEL   (1 << 0) /* xx1 Interrupt on level (vs. edge) */
-#  define IOEXPANDER_VAL_HIGH    (1 << 2) /* 001 Interrupt on high level */
-#  define IOEXPANDER_VAL_LOW     (3 << 2) /* 011 Interrupt on low level */
-#  define IOEXPANDER_VAL_RISING  (2 << 2) /* 010 Interrupt on rising edge */
-#  define IOEXPANDER_VAL_FALLING (4 << 2) /* 100 Interrupt on falling edge */
-#  define IOEXPANDER_VAL_BOTH    (6 << 2) /* 110 Interrupt on both edges */
+#define IOEXPANDER_OPTION_INTCFG 2  /* Configure interrupt for a pin */
+#  define IOEXPANDER_VAL_LEVEL   1  /* xx1 Interrupt on level (vs. edge) */
+#  define IOEXPANDER_VAL_HIGH    1  /* 001 Interrupt on high level */
+#  define IOEXPANDER_VAL_LOW     3  /* 011 Interrupt on low level */
+#  define IOEXPANDER_VAL_RISING  2  /* 010 Interrupt on rising edge */
+#  define IOEXPANDER_VAL_FALLING 4  /* 100 Interrupt on falling edge */
+#  define IOEXPANDER_VAL_BOTH    6  /* 110 Interrupt on both edges */
+
+#define PINSET_ALL               (~((ioe_pinset_t)0))
 
 /* Access macros ************************************************************/