diff --git a/ChangeLog b/ChangeLog
index adb52afce7..f472e87cd0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3419,4 +3419,10 @@
 	  on the Shenzhou board.
 	* graphics/nxmu:  Correct some bad parameter checking that caused
 	  failures when DEBUG was enabled.
+	* arch/arm/src/armv7-m/nvic.h:  Add bit definitions for the AIRCR
+	  register.
+	* drivers/input/ads7843.c:  Need semaphore protection in logic
+	  that samples the position.
+	* drivers/lcd/ssd1289.c:  On some platforms we are unable to
+	  read the device ID -- reason unknown; workaround in place.
 
diff --git a/arch/arm/src/armv7-m/nvic.h b/arch/arm/src/armv7-m/nvic.h
index 1d30c5f7c2..ae56118c97 100644
--- a/arch/arm/src/armv7-m/nvic.h
+++ b/arch/arm/src/armv7-m/nvic.h
@@ -500,6 +500,14 @@
 #define NVIC_SYSHCON_BUSFAULTENA        (1 << 17) /* Bit 17: BusFault enabled */
 #define NVIC_SYSHCON_USGFAULTENA        (1 << 18) /* Bit 18: UsageFault enabled */
 
+/* Application Interrupt and Reset Control Register (AIRCR) */
+                                                  /* Bit 0:  Reserved */
+#define NVIC_AIRC_VECTCLRACTIVE         (1 << 1)  /* Bit 1:  Reserved for debug use */
+#define NVIC_AIRC_SYSRESETREQ           (1 << 2)  /* Bit 2:  System reset */
+                                                  /* Bits 3-14:  Reserved */
+#define NVIC_AIRC_ENDIANNESS            (1 << 15) /* Bit 15: 1=Big endian */
+                                                  /* Bits 16-31:  Reserved */
+
 /* Debug Exception and Monitor Control Register (DEMCR) */
 
 #define NVIC_DEMCR_VCCORERESET          (1 << 0)  /* Bit 0:  Reset Vector Catch */
diff --git a/drivers/input/ads7843e.c b/drivers/input/ads7843e.c
index 07e5e515df..679c25113e 100644
--- a/drivers/input/ads7843e.c
+++ b/drivers/input/ads7843e.c
@@ -555,6 +555,7 @@ static void ads7843e_worker(FAR void *arg)
   FAR struct ads7843e_dev_s    *priv = (FAR struct ads7843e_dev_s *)arg;
   FAR struct ads7843e_config_s *config;
   bool                          pendown;
+  int                           ret;
 
   ASSERT(priv != NULL);
 
@@ -565,10 +566,26 @@ static void ads7843e_worker(FAR void *arg)
   config = priv->config;
   DEBUGASSERT(config != NULL);
 
-  /* Disable the watchdog timer */
+  /* Disable the watchdog timer.  This is safe because it is started only
+   * by this function and this function is serialized on the worker thread.
+   */
 
   wd_cancel(priv->wdog);
 
+  /* Get exclusive access to the driver data structure */
+
+  do
+    {
+      ret = sem_wait(&priv->devsem);
+
+      /* This should only fail if the wait was canceled by an signal
+       * (and the worker thread will receive a lot of signals).
+       */
+
+      DEBUGASSERT(ret == OK || errno == EINTR);
+    }
+  while (ret < 0);
+
   /* Check for pen up or down by reading the PENIRQ GPIO. */
 
   pendown = config->pendown(config);
@@ -645,6 +662,10 @@ static void ads7843e_worker(FAR void *arg)
 errout:
   (void)ads7843e_sendcmd(priv, ADS7843_CMD_ENABPINIRQ);
   config->enable(config, true);
+
+  /* Release our lock on the state structure */
+
+  sem_post(&priv->devsem);
 }
 
 /****************************************************************************
diff --git a/drivers/lcd/ssd1289.c b/drivers/lcd/ssd1289.c
index 3d5ba96d31..f5f11b87dc 100644
--- a/drivers/lcd/ssd1289.c
+++ b/drivers/lcd/ssd1289.c
@@ -931,9 +931,27 @@ static inline int ssd1289_hwinitialize(FAR struct ssd1289_dev_s *priv)
 
   lcd->select(lcd);
 
+  /* Read the device ID.  Skip verification of the device ID is the LCD is
+   * write-only. What choice do we have?
+   */
+
 #ifndef CONFIG_LCD_NOGETRUN
   id = ssd1289_readreg(lcd, SSD1289_DEVCODE);
-  lcddbg("LCD ID: %04x\n", id);
+  if (id != 0)
+    {
+      lcddbg("LCD ID: %04x\n", id);
+    }
+
+  /* If we could not get the ID, then let's just assume that this is an SSD1289.
+   * Perhaps we have some early register access issues.  This seems to happen.
+   * But then perhaps we should not even bother to read the device ID at all?
+   */
+
+  else
+    {
+      lcddbg("No LCD ID, assuming SSD1289\n");
+      id = SSD1289_DEVCODE_VALUE;
+    }
 
   /* Check if the ID is for the SSD1289 */