diff --git a/drivers/audio/audio_null.c b/drivers/audio/audio_null.c
index d6c522101a..4ed7a010a6 100644
--- a/drivers/audio/audio_null.c
+++ b/drivers/audio/audio_null.c
@@ -653,6 +653,8 @@ static int null_enqueuebuffer(FAR struct audio_lowerhalf_s *dev,
   FAR struct null_dev_s *priv = (FAR struct null_dev_s *)dev;
   bool done;
 
+  DEBUGASSERT(priv && apb && priv->dev.upper);
+
   audinfo("apb=%p curbyte=%d nbytes=%d\n", apb, apb->curbyte, apb->nbytes);
 
   /* Say that we consumed all of the data */
@@ -663,10 +665,6 @@ static int null_enqueuebuffer(FAR struct audio_lowerhalf_s *dev,
 
   done = ((apb->flags & AUDIO_APB_FINAL) != 0);
 
-  /* And return the buffer to the upper level */
-
-  DEBUGASSERT(priv && apb && priv->dev.upper);
-
   /* The buffer belongs to to an upper level.  Just forward the event to
    * the next level up.
    */
diff --git a/drivers/input/ajoystick.c b/drivers/input/ajoystick.c
index 2868e1542a..76c93e43c7 100644
--- a/drivers/input/ajoystick.c
+++ b/drivers/input/ajoystick.c
@@ -201,7 +201,7 @@ static inline int ajoy_takesem(sem_t *sem)
 #if !defined(CONFIG_DISABLE_POLL) || !defined(CONFIG_DISABLE_SIGNALS)
 static void ajoy_enable(FAR struct ajoy_upperhalf_s *priv)
 {
-  FAR const struct ajoy_lowerhalf_s *lower = priv->au_lower;
+  FAR const struct ajoy_lowerhalf_s *lower;
   FAR struct ajoy_open_s *opriv;
   ajoy_buttonset_t press;
   ajoy_buttonset_t release;
@@ -210,8 +210,9 @@ static void ajoy_enable(FAR struct ajoy_upperhalf_s *priv)
   int i;
 #endif
 
-  DEBUGASSERT(priv && priv->au_lower);
+  DEBUGASSERT(priv);
   lower = priv->au_lower;
+  DEBUGASSERT(lower);
 
   /* This routine is called both task level and interrupt level, so
    * interrupts must be disabled.
@@ -295,7 +296,7 @@ static void ajoy_interrupt(FAR const struct ajoy_lowerhalf_s *lower,
 
 static void ajoy_sample(FAR struct ajoy_upperhalf_s *priv)
 {
-  FAR const struct ajoy_lowerhalf_s *lower = priv->au_lower;
+  FAR const struct ajoy_lowerhalf_s *lower;
   FAR struct ajoy_open_s *opriv;
   ajoy_buttonset_t sample;
 #if !defined(CONFIG_DISABLE_POLL) || !defined(CONFIG_DISABLE_SIGNALS)
@@ -308,8 +309,9 @@ static void ajoy_sample(FAR struct ajoy_upperhalf_s *priv)
   int i;
 #endif
 
-  DEBUGASSERT(priv && priv->au_lower);
+  DEBUGASSERT(priv);
   lower = priv->au_lower;
+  DEBUGASSERT(lower);
 
   /* This routine is called both task level and interrupt level, so
    * interrupts must be disabled.
diff --git a/drivers/input/djoystick.c b/drivers/input/djoystick.c
index 62f62fe45a..c0559208fb 100644
--- a/drivers/input/djoystick.c
+++ b/drivers/input/djoystick.c
@@ -201,7 +201,7 @@ static inline int djoy_takesem(sem_t *sem)
 #if !defined(CONFIG_DISABLE_POLL) || !defined(CONFIG_DISABLE_SIGNALS)
 static void djoy_enable(FAR struct djoy_upperhalf_s *priv)
 {
-  FAR const struct djoy_lowerhalf_s *lower = priv->du_lower;
+  FAR const struct djoy_lowerhalf_s *lower;
   FAR struct djoy_open_s *opriv;
   djoy_buttonset_t press;
   djoy_buttonset_t release;
@@ -210,8 +210,9 @@ static void djoy_enable(FAR struct djoy_upperhalf_s *priv)
   int i;
 #endif
 
-  DEBUGASSERT(priv && priv->du_lower);
+  DEBUGASSERT(priv);
   lower = priv->du_lower;
+  DEBUGASSERT(lower);
 
   /* This routine is called both task level and interrupt level, so
    * interrupts must be disabled.
@@ -295,7 +296,7 @@ static void djoy_interrupt(FAR const struct djoy_lowerhalf_s *lower,
 
 static void djoy_sample(FAR struct djoy_upperhalf_s *priv)
 {
-  FAR const struct djoy_lowerhalf_s *lower = priv->du_lower;
+  FAR const struct djoy_lowerhalf_s *lower;
   FAR struct djoy_open_s *opriv;
   djoy_buttonset_t sample;
 #if !defined(CONFIG_DISABLE_POLL) || !defined(CONFIG_DISABLE_SIGNALS)
@@ -308,8 +309,9 @@ static void djoy_sample(FAR struct djoy_upperhalf_s *priv)
   int i;
 #endif
 
-  DEBUGASSERT(priv && priv->du_lower);
+  DEBUGASSERT(priv);
   lower = priv->du_lower;
+  DEBUGASSERT(lower);
 
   /* This routine is called both task level and interrupt level, so
    * interrupts must be disabled.
diff --git a/drivers/modem/u-blox.c b/drivers/modem/u-blox.c
index 95a7fc29d2..014dac102e 100644
--- a/drivers/modem/u-blox.c
+++ b/drivers/modem/u-blox.c
@@ -141,13 +141,16 @@ static int ubxmdm_ioctl(FAR struct file* filep,
                         unsigned long arg)
 {
   FAR struct inode*         inode = filep->f_inode;
-  FAR struct ubxmdm_upper*  upper = inode->i_private;
-  FAR struct ubxmdm_lower*  lower = upper->lower;
+  FAR struct ubxmdm_upper*  upper;
+  FAR struct ubxmdm_lower*  lower;
   int                       ret;
   FAR struct ubxmdm_status* status;
 
   m_info("cmd: %d arg: %ld\n", cmd, arg);
-  DEBUGASSERT(upper && lower);
+  upper = inode->i_private;
+  DEBUGASSERT(upper != NULL);
+  lower = upper->lower;
+  DEBUGASSERT(lower != NULL);
 
   switch (cmd)
     {
@@ -320,8 +323,9 @@ void ubxmdm_unregister(FAR void *handle)
   FAR struct ubxmdm_lower *lower;
 
   upper = (FAR struct ubxmdm_upper*) handle;
+  DEBUGASSERT(upper != NULL);
   lower = upper->lower;
-  DEBUGASSERT(upper && lower);
+  DEBUGASSERT(lower != NULL);
 
   m_info("Unregistering: %s\n", upper->path);
 
diff --git a/drivers/pwm.c b/drivers/pwm.c
index 78b60751c0..24c5ae4105 100644
--- a/drivers/pwm.c
+++ b/drivers/pwm.c
@@ -318,11 +318,13 @@ static ssize_t pwm_write(FAR struct file *filep, FAR const char *buffer,
 #ifdef CONFIG_PWM_PULSECOUNT
 static int pwm_start(FAR struct pwm_upperhalf_s *upper, unsigned int oflags)
 {
-  FAR struct pwm_lowerhalf_s *lower = upper->dev;
+  FAR struct pwm_lowerhalf_s *lower;
   irqstate_t flags;
   int ret = OK;
 
-  DEBUGASSERT(upper != NULL && lower->ops->start != NULL);
+  DEBUGASSERT(upper != NULL);
+  lower = upper->dev;
+  DEBUGASSERT(lower != NULL && lower->ops->start != NULL);
 
   /* Verify that the PWM is not already running */
 
@@ -385,10 +387,12 @@ static int pwm_start(FAR struct pwm_upperhalf_s *upper, unsigned int oflags)
 #else
 static int pwm_start(FAR struct pwm_upperhalf_s *upper, unsigned int oflags)
 {
-  FAR struct pwm_lowerhalf_s *lower = upper->dev;
+  FAR struct pwm_lowerhalf_s *lower;
   int ret = OK;
 
-  DEBUGASSERT(upper != NULL && lower->ops->start != NULL);
+  DEBUGASSERT(upper != NULL);
+  lower = upper->dev;
+  DEBUGASSERT(lower != NULL && lower->ops->start != NULL);
 
   /* Verify that the PWM is not already running */
 
diff --git a/drivers/sensors/qencoder.c b/drivers/sensors/qencoder.c
index 7f6edd0978..ead9ec6de7 100644
--- a/drivers/sensors/qencoder.c
+++ b/drivers/sensors/qencoder.c
@@ -276,12 +276,15 @@ static ssize_t qe_write(FAR struct file *filep, FAR const char *buffer, size_t b
 static int qe_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
 {
   FAR struct inode          *inode = filep->f_inode;
-  FAR struct qe_upperhalf_s *upper = inode->i_private;
-  FAR struct qe_lowerhalf_s *lower = upper->lower;
+  FAR struct qe_upperhalf_s *upper;
+  FAR struct qe_lowerhalf_s *lower;
   int                        ret;
 
   sninfo("cmd: %d arg: %ld\n", cmd, arg);
-  DEBUGASSERT(upper && lower);
+  upper = inode->i_private;
+  DEBUGASSERT(upper != NULL);
+  lower = upper->lower;
+  DEBUGASSERT(lower != NULL);
 
   /* Get exclusive access to the device structures */
 
diff --git a/drivers/timers/timer.c b/drivers/timers/timer.c
index 667be5276d..4cfdacaac7 100644
--- a/drivers/timers/timer.c
+++ b/drivers/timers/timer.c
@@ -254,12 +254,15 @@ static ssize_t timer_write(FAR struct file *filep, FAR const char *buffer,
 static int timer_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
 {
   FAR struct inode             *inode = filep->f_inode;
-  FAR struct timer_upperhalf_s *upper = inode->i_private;
-  FAR struct timer_lowerhalf_s *lower = upper->lower;
+  FAR struct timer_upperhalf_s *upper;
+  FAR struct timer_lowerhalf_s *lower;
   int                           ret;
 
   tmrinfo("cmd: %d arg: %ld\n", cmd, arg);
-  DEBUGASSERT(upper && lower);
+  upper = inode->i_private;
+  DEBUGASSERT(upper != NULL);
+  lower = upper->lower;
+  DEBUGASSERT(lower != NULL);
 
   /* Handle built-in ioctl commands */
 
diff --git a/drivers/timers/watchdog.c b/drivers/timers/watchdog.c
index e9320a9612..7ccab15a06 100644
--- a/drivers/timers/watchdog.c
+++ b/drivers/timers/watchdog.c
@@ -240,12 +240,15 @@ static ssize_t wdog_write(FAR struct file *filep, FAR const char *buffer, size_t
 static int wdog_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
 {
   FAR struct inode                *inode = filep->f_inode;
-  FAR struct watchdog_upperhalf_s *upper = inode->i_private;
-  FAR struct watchdog_lowerhalf_s *lower = upper->lower;
+  FAR struct watchdog_upperhalf_s *upper;
+  FAR struct watchdog_lowerhalf_s *lower;
   int                              ret;
 
   wdinfo("cmd: %d arg: %ld\n", cmd, arg);
-  DEBUGASSERT(upper && lower);
+  upper = inode->i_private;
+  DEBUGASSERT(upper != NULL);
+  lower = upper->lower;
+  DEBUGASSERT(lower != NULL);
 
   /* Get exclusive access to the device structures */
 
@@ -533,8 +536,9 @@ void watchdog_unregister(FAR void *handle)
   /* Recover the pointer to the upper-half driver state */
 
   upper = (FAR struct watchdog_upperhalf_s *)handle;
+  DEBUGASSERT(upper != NULL);
   lower = upper->lower;
-  DEBUGASSERT(upper && lower);
+  DEBUGASSERT(lower != NULL);
 
   wdinfo("Unregistering: %s\n", upper->path);