arch: Disable priority inheritance on all semaphores used for signaling in all SPI drivers

arch/arm/src/efm32/efm32_spi.c

@@ -53,6 +53,7 @@
 #include <nuttx/arch.h>
 #include <nuttx/wdog.h>
 #include <nuttx/clock.h>
+#include <nuttx/semaphore.h>
 #include <nuttx/spi/spi.h>
 
 #include <arch/board/board.h>
@@ -1640,6 +1641,13 @@ static int spi_portinitialize(struct efm32_spidev_s *priv)
 
   (void)sem_init(&priv->rxdmasem, 0, 0);
   (void)sem_init(&priv->txdmasem, 0, 0);
+
+  /* These semaphores are used for signaling and, hence, should not have
+   * priority inheritance enabled.
+   */
+
+   sem_setprotocol(&priv->rxdmasem, SEM_PRIO_NONE);
+   sem_setprotocol(&priv->txdmasem, SEM_PRIO_NONE);
 #endif
 
   /* Enable SPI */

arch/arm/src/imx1/imx_spi.c

@@ -50,6 +50,7 @@
 #include <nuttx/spi/spi.h>
 
 #include <nuttx/irq.h>
+#include <nuttx/semaphore.h>
 #include <arch/board/board.h>
 
 #include "up_internal.h"
@@ -1116,7 +1117,13 @@ FAR struct spi_dev_s *imx_spibus_initialize(int port)
   /* Initialize the state structure */
 
 #ifndef CONFIG_SPI_POLLWAIT
+  /* Initialize the semaphore that is used to wake up the waiting
+   * thread when the DMA transfer completes.  This semaphore is used for
+   * signaling and, hence, should not have priority inheritance enabled.
+   */
+
    sem_init(&priv->waitsem, 0, 0);
+   sem_setprotocol(&priv->waitsem, SEM_PRIO_NONE);
 #endif
    sem_init(&priv->exclsem, 0, 1);
 

arch/arm/src/sam34/sam_spi.c

@@ -56,6 +56,7 @@
 #include <nuttx/arch.h>
 #include <nuttx/wdog.h>
 #include <nuttx/clock.h>
+#include <nuttx/semaphore.h>
 #include <nuttx/spi/spi.h>
 
 #include "up_internal.h"
@@ -1882,10 +1883,12 @@ struct spi_dev_s *sam_spibus_initialize(int port)
 
 #ifdef CONFIG_SAM34_SPI_DMA
       /* Initialize the SPI semaphore that is used to wake up the waiting
-       * thread when the DMA transfer completes.
+       * thread when the DMA transfer completes.  This semaphore is used for
+       * signaling and, hence, should not have priority inheritance enabled.
        */
 
       sem_init(&spics->dmawait, 0, 0);
+      sem_setprotocol(&spics->dmawait, SEM_PRIO_NONE);
 
       /* Create a watchdog time to catch DMA timeouts */
 

arch/arm/src/sama5/sam_spi.c

@@ -60,6 +60,7 @@
 #include <nuttx/arch.h>
 #include <nuttx/wdog.h>
 #include <nuttx/clock.h>
+#include <nuttx/semaphore.h>
 #include <nuttx/spi/spi.h>
 
 #include "up_internal.h"
@@ -1810,10 +1811,12 @@ struct spi_dev_s *sam_spibus_initialize(int port)
 
 #ifdef CONFIG_SAMA5_SPI_DMA
       /* Initialize the SPI semaphore that is used to wake up the waiting
-       * thread when the DMA transfer completes.
+       * thread when the DMA transfer completes.  This semaphore is used for
+       * signaling and, hence, should not have priority inheritance enabled.
        */
 
       sem_init(&spics->dmawait, 0, 0);
+      sem_setprotocol(&spics->dmawait, SEM_PRIO_NONE);
 
       /* Create a watchdog time to catch DMA timeouts */
 

arch/arm/src/samv7/sam_qspi.c

@@ -55,6 +55,7 @@
 #include <nuttx/wdog.h>
 #include <nuttx/clock.h>
 #include <nuttx/kmalloc.h>
+#include <nuttx/semaphore.h>
 #include <nuttx/spi/qspi.h>
 
 #include "up_internal.h"
@@ -1790,10 +1791,12 @@ struct qspi_dev_s *sam_qspi_initialize(int intf)
         }
 
       /* Initialize the QSPI semaphore that is used to wake up the waiting
-       * thread when the DMA transfer completes.
+       * thread when the DMA transfer completes.  This semaphore is used for
+       * signaling and, hence, should not have priority inheritance enabled.
        */
 
       sem_init(&priv->dmawait, 0, 0);
+      sem_setprotocol(&priv->dmawait, SEM_PRIO_NONE);
 
       /* Create a watchdog time to catch DMA timeouts */
 

arch/arm/src/samv7/sam_spi.c

@@ -56,6 +56,7 @@
 #include <nuttx/arch.h>
 #include <nuttx/wdog.h>
 #include <nuttx/clock.h>
+#include <nuttx/semaphore.h>
 #include <nuttx/spi/spi.h>
 
 #include "up_internal.h"
@@ -2164,10 +2165,12 @@ FAR struct spi_dev_s *sam_spibus_initialize(int port)
 
 #ifdef CONFIG_SAMV7_SPI_DMA
       /* Initialize the SPI semaphore that is used to wake up the waiting
-       * thread when the DMA transfer completes.
+       * thread when the DMA transfer completes.  This semaphore is used for
+       * signaling and, hence, should not have priority inheritance enabled.
        */
 
       sem_init(&spics->dmawait, 0, 0);
+      sem_setprotocol(&spics->dmawait, SEM_PRIO_NONE);
 
       /* Create a watchdog time to catch DMA timeouts */
 

arch/arm/src/stm32/stm32_spi.c

@@ -70,6 +70,7 @@
 
 #include <nuttx/irq.h>
 #include <nuttx/arch.h>
+#include <nuttx/semaphore.h>
 #include <nuttx/spi/spi.h>
 
 #include <arch/board/board.h>
@@ -1719,12 +1720,18 @@ static void spi_bus_initialize(FAR struct stm32_spidev_s *priv)
 
   sem_init(&priv->exclsem, 0, 1);
 
-  /* Initialize the SPI semaphores that is used to wait for DMA completion */
-
 #ifdef CONFIG_STM32_SPI_DMA
+  /* Initialize the SPI semaphores that is used to wait for DMA completion.
+   * This semaphore is used for signaling and, hence, should not have
+   * priority inheritance enabled.
+   */
+
   sem_init(&priv->rxsem, 0, 0);
   sem_init(&priv->txsem, 0, 0);
 
+  sem_setprotocol(&priv->rxsem, SEM_PRIO_NONE);
+  sem_setprotocol(&priv->txsem, SEM_PRIO_NONE);
+
   /* Get DMA channels.  NOTE: stm32_dmachannel() will always assign the DMA channel.
    * if the channel is not available, then stm32_dmachannel() will block and wait
    * until the channel becomes available.  WARNING: If you have another device sharing

arch/arm/src/stm32f7/stm32_spi.c

@@ -72,6 +72,7 @@
 
 #include <nuttx/irq.h>
 #include <nuttx/arch.h>
+#include <nuttx/semaphore.h>
 #include <nuttx/spi/spi.h>
 
 #include <arch/board/board.h>
@@ -1665,16 +1666,22 @@ static void spi_bus_initialize(FAR struct stm32_spidev_s *priv)
 
   spi_putreg(priv, STM32_SPI_CRCPR_OFFSET, 7);
 
-  /* Initialize the SPI semaphore that enforces mutually exclusive access */
+  /* Initialize the SPI semaphore that enforces mutually exclusive access. */
 
   sem_init(&priv->exclsem, 0, 1);
 
-  /* Initialize the SPI semaphores that is used to wait for DMA completion */
-
 #ifdef CONFIG_STM32F7_SPI_DMA
+  /* Initialize the SPI semaphores that is used to wait for DMA completion.
+   * This semaphore is used for signaling and, hence, should not have
+   * priority inheritance enabled.
+   */
+
   sem_init(&priv->rxsem, 0, 0);
   sem_init(&priv->txsem, 0, 0);
 
+  sem_setprotocol(&priv->rxsem, SEM_PRIO_NONE);
+  sem_setprotocol(&priv->txsem, SEM_PRIO_NONE);
+
   /* Get DMA channels.  NOTE: stm32_dmachannel() will always assign the DMA channel.
    * if the channel is not available, then stm32_dmachannel() will block and wait
    * until the channel becomes available.  WARNING: If you have another device sharing

arch/arm/src/stm32l4/stm32l4_qspi.c

@@ -55,6 +55,7 @@
 #include <nuttx/wdog.h>
 #include <nuttx/clock.h>
 #include <nuttx/kmalloc.h>
+#include <nuttx/semaphore.h>
 #include <nuttx/spi/qspi.h>
 
 #include "up_internal.h"
@@ -2501,10 +2502,12 @@ struct qspi_dev_s *stm32l4_qspi_initialize(int intf)
         }
 
       /* Initialize the QSPI semaphore that is used to wake up the waiting
-       * thread when the DMA transfer completes.
+       * thread when the DMA transfer completes.  This semaphore is used for
+       * signaling and, hence, should not have priority inheritance enabled.
        */
 
       sem_init(&priv->dmawait, 0, 0);
+      sem_setprotocol(&priv->dmawait, SEM_PRIO_NONE);
 
       /* Create a watchdog time to catch DMA timeouts */
 
@@ -2526,10 +2529,13 @@ struct qspi_dev_s *stm32l4_qspi_initialize(int intf)
           goto errout_with_dmadog;
         }
 
-      /* Initialize the semaphore that blocks until the operation completes */
+      /* Initialize the semaphore that blocks until the operation completes.
+       * This semaphore is used for signaling and, hence, should not have
+       * priority inheritance enabled.
+       */
 
       sem_init(&priv->op_sem, 0, 0);
-
+      sem_setprotocol(&priv->op_sem, SEM_PRIO_NONE);
 #endif
 
       /* Perform hardware initialization.  Puts the QSPI into an active

arch/arm/src/stm32l4/stm32l4_spi.c

@@ -76,6 +76,7 @@
 
 #include <nuttx/irq.h>
 #include <nuttx/arch.h>
+#include <nuttx/semaphore.h>
 #include <nuttx/spi/spi.h>
 
 #include <arch/board/board.h>
@@ -1517,6 +1518,13 @@ static void spi_bus_initialize(FAR struct stm32l4_spidev_s *priv)
   sem_init(&priv->rxsem, 0, 0);
   sem_init(&priv->txsem, 0, 0);
 
+  /* These semaphores are used for signaling and, hence, should not have
+   * priority inheritance enabled.
+   */
+
+  sem_setprotocol(&priv->rxsem, SEM_PRIO_NONE);
+  sem_setprotocol(&priv->txsem, SEM_PRIO_NONE);
+
   /* Get DMA channels.  NOTE: stm32l4_dmachannel() will always assign the DMA channel.
    * if the channel is not available, then stm32l4_dmachannel() will block and wait
    * until the channel becomes available.  WARNING: If you have another device sharing