drivers: Disable priority inheritance on all semaphores used for signaling

drivers/input/ads7843e.c

@@ -71,6 +71,7 @@
 #include <nuttx/spi/spi.h>
 #include <nuttx/wqueue.h>
 
+#include <nuttx/semaphore.h>
 #include <nuttx/input/touchscreen.h>
 #include <nuttx/input/ads7843e.h>
 
@@ -1184,9 +1185,17 @@ int ads7843e_register(FAR struct spi_dev_s *spi,
   priv->threshx = INVALID_THRESHOLD; /* Initialize thresholding logic */
   priv->threshy = INVALID_THRESHOLD; /* Initialize thresholding logic */
 
+  /* Initialize semaphores */
+
   sem_init(&priv->devsem,  0, 1);    /* Initialize device structure semaphore */
   sem_init(&priv->waitsem, 0, 0);    /* Initialize pen event wait semaphore */
 
+  /* The pen event semaphore is used for signaling and, hence, should not
+   * have priority inheritance enabled.
+   */
+
+  sem_setprotocol(&priv->waitsem, SEM_PRIO_NONE);
+
   /* Make sure that interrupts are disabled */
 
   config->clear(config);

drivers/input/max11802.c

@@ -65,6 +65,7 @@
 #include <nuttx/fs/fs.h>
 #include <nuttx/spi/spi.h>
 
+#include <nuttx/semaphore.h>
 #include <nuttx/input/touchscreen.h>
 #include <nuttx/input/max11802.h>
 
@@ -1187,9 +1188,17 @@ int max11802_register(FAR struct spi_dev_s *spi,
   priv->threshx = INVALID_THRESHOLD; /* Initialize thresholding logic */
   priv->threshy = INVALID_THRESHOLD; /* Initialize thresholding logic */
 
+  /* Initialize semaphores */
+
   sem_init(&priv->devsem,  0, 1);    /* Initialize device structure semaphore */
   sem_init(&priv->waitsem, 0, 0);    /* Initialize pen event wait semaphore */
 
+  /* The pen event semaphore is used for signaling and, hence, should not
+   * have priority inheritance enabled.
+   */
+
+  sem_setprotocol(&priv->waitsem, SEM_PRIO_NONE);
+
   /* Make sure that interrupts are disabled */
 
   config->clear(config);

drivers/input/mxt.c

@@ -65,6 +65,7 @@
 #include <nuttx/i2c/i2c_master.h>
 #include <nuttx/wqueue.h>
 
+#include <nuttx/semaphore.h>
 #include <nuttx/input/touchscreen.h>
 #include <nuttx/input/mxt.h>
 
@@ -1884,9 +1885,17 @@ int mxt_register(FAR struct i2c_master_s *i2c,
   priv->i2c   = i2c;              /* Save the SPI device handle */
   priv->lower = lower;            /* Save the board configuration */
 
+  /* Initialize semaphores */
+
   sem_init(&priv->devsem, 0, 1);  /* Initialize device semaphore */
   sem_init(&priv->waitsem, 0, 0); /* Initialize event wait semaphore */
 
+  /* The event wait semaphore is used for signaling and, hence, should not
+   * have priority inheritance enabled.
+   */
+
+  sem_setprotocol(&priv->waitsem, SEM_PRIO_NONE);
+
   /* Make sure that interrupts are disabled */
 
   MXT_CLEAR(lower);