arch/arm/rp23xx: Set priority for svcall exception

Fixes apache#15503.

Signed-off-by: Ian Douglas Scott <[email protected]>

arch/arm/src/rp23xx/rp23xx_irq.c

@@ -181,6 +181,27 @@ static int rp23xx_reserved(int irq, void *context, void *arg)
 }
 #endif
 
+/****************************************************************************
+ * Name: rp23xx_prioritize_syscall
+ *
+ * Description:
+ *   Set the priority of an exception.  This function may be needed
+ *   internally even if support for prioritized interrupts is not enabled.
+ *
+ ****************************************************************************/
+
+static inline void rp23xx_prioritize_syscall(int priority)
+{
+  uint32_t regval;
+
+  /* SVCALL is system handler 11 */
+
+  regval  = getreg32(NVIC_SYSH8_11_PRIORITY);
+  regval &= ~NVIC_SYSH_PRIORITY_PR11_MASK;
+  regval |= (priority << NVIC_SYSH_PRIORITY_PR11_SHIFT);
+  putreg32(regval, NVIC_SYSH8_11_PRIORITY);
+}
+
 /****************************************************************************
  * Name: rp23xx_clrpend
  *
@@ -276,6 +297,8 @@ void up_irqinitialize(void)
   irq_attach(RP23XX_IRQ_SVCALL, arm_svcall, NULL);
   irq_attach(RP23XX_IRQ_HARDFAULT, arm_hardfault, NULL);
 
+  rp23xx_prioritize_syscall(NVIC_SYSH_SVCALL_PRIORITY);
+
   /* Attach all other processor exceptions (except reset and sys tick) */
 
 #ifdef CONFIG_DEBUG_FEATURES