diff --git a/Marlin/src/HAL/STM32/HAL.cpp b/Marlin/src/HAL/STM32/HAL.cpp
index c09592a5645c16a8951b2be39b668ab880b9acca..1430182fc3665b6a517ef6e5e47f254856165819 100644
--- a/Marlin/src/HAL/STM32/HAL.cpp
+++ b/Marlin/src/HAL/STM32/HAL.cpp
@@ -79,7 +79,7 @@ void HAL_init() {
while (!LL_PWR_IsActiveFlag_BRR()); // Wait until backup regulator is initialized
#endif
- SetSoftwareSerialTimerInterruptPriority();
+ SetTimerInterruptPriorities();
TERN_(EMERGENCY_PARSER, USB_Hook_init());
}
diff --git a/Marlin/src/HAL/STM32/Servo.cpp b/Marlin/src/HAL/STM32/Servo.cpp
index 5fb8e3cd6ae75479dcaf3e19496cba778a354aed..0a79d474d44a78f5d300e3267cb36909ce1a19fa 100644
--- a/Marlin/src/HAL/STM32/Servo.cpp
+++ b/Marlin/src/HAL/STM32/Servo.cpp
@@ -33,6 +33,18 @@ static libServo *servos[NUM_SERVOS] = {0};
constexpr millis_t servoDelay[] = SERVO_DELAY;
static_assert(COUNT(servoDelay) == NUM_SERVOS, "SERVO_DELAY must be an array NUM_SERVOS long.");
+// Initialize to the default timer priority. This will be overridden by a call from timers.cpp.
+// This allows all timer interrupt priorities to be managed from a single location in the HAL.
+static uint32_t servo_interrupt_priority = NVIC_EncodePriority(NVIC_GetPriorityGrouping(), TIM_IRQ_PRIO, TIM_IRQ_SUBPRIO);
+
+// This must be called after the STM32 Servo class has intialized the timer.
+// It may only be needed after the first call to attach(), but it is possible
+// that is is necessary after every detach() call. To be safe this is currently
+// called after every call to attach().
+static void fixServoTimerInterruptPriority() {
+ NVIC_SetPriority(getTimerUpIrq(TIMER_SERVO), servo_interrupt_priority);
+}
+
libServo::libServo()
: delay(servoDelay[servoCount]),
was_attached_before_pause(false),
@@ -44,13 +56,17 @@ libServo::libServo()
int8_t libServo::attach(const int pin) {
if (servoCount >= MAX_SERVOS) return -1;
if (pin > 0) servo_pin = pin;
- return stm32_servo.attach(servo_pin);
+ auto result = stm32_servo.attach(servo_pin);
+ fixServoTimerInterruptPriority();
+ return result;
}
int8_t libServo::attach(const int pin, const int min, const int max) {
if (servoCount >= MAX_SERVOS) return -1;
if (pin > 0) servo_pin = pin;
- return stm32_servo.attach(servo_pin, min, max);
+ auto result = stm32_servo.attach(servo_pin, min, max);
+ fixServoTimerInterruptPriority();
+ return result;
}
void libServo::move(const int value) {
@@ -86,5 +102,9 @@ void libServo::resume_all_servos() {
if (servo) servo->resume();
}
+void libServo::setInterruptPriority(uint32_t preemptPriority, uint32_t subPriority) {
+ servo_interrupt_priority = NVIC_EncodePriority(NVIC_GetPriorityGrouping(), preemptPriority, subPriority);
+}
+
#endif // HAS_SERVOS
#endif // ARDUINO_ARCH_STM32 && !STM32GENERIC
diff --git a/Marlin/src/HAL/STM32/Servo.h b/Marlin/src/HAL/STM32/Servo.h
index 50ae1a9b946e46246fffd8ab747f22b3cbcaa3e7..534cb97e39f717035741d450ae413948ef20306f 100644
--- a/Marlin/src/HAL/STM32/Servo.h
+++ b/Marlin/src/HAL/STM32/Servo.h
@@ -41,6 +41,7 @@ class libServo {
static void pause_all_servos();
static void resume_all_servos();
+ static void setInterruptPriority(uint32_t preemptPriority, uint32_t subPriority);
private:
Servo stm32_servo;
diff --git a/Marlin/src/HAL/STM32/timers.cpp b/Marlin/src/HAL/STM32/timers.cpp
index 5383c82212d42698de36f2783b6b41df5b10378d..e98a6a556093b516e15968b12c3106f4d1300def 100644
--- a/Marlin/src/HAL/STM32/timers.cpp
+++ b/Marlin/src/HAL/STM32/timers.cpp
@@ -29,26 +29,41 @@
#define NUM_HARDWARE_TIMERS 2
+// Default timer priorities. Override by specifying alternate priorities in the board pins file.
+// The TONE timer is not present here, as it currently cannot be set programmatically. It is set
+// by defining TIM_IRQ_PRIO in the variant.h or platformio.ini file, which adjusts the default
+// priority for STM32 HardwareTimer objects.
+#define SWSERIAL_TIMER_IRQ_PRIO_DEFAULT 1 // Requires tight bit timing to communicate reliably with TMC drivers
+#define SERVO_TIMER_IRQ_PRIO_DEFAULT 1 // Requires tight PWM timing to control a BLTouch reliably
+#define STEP_TIMER_IRQ_PRIO_DEFAULT 2
+#define TEMP_TIMER_IRQ_PRIO_DEFAULT 14 // Low priority avoids interference with other hardware and timers
+
#ifndef STEP_TIMER_IRQ_PRIO
- #define STEP_TIMER_IRQ_PRIO 2
+ #define STEP_TIMER_IRQ_PRIO STEP_TIMER_IRQ_PRIO_DEFAULT
#endif
#ifndef TEMP_TIMER_IRQ_PRIO
- #define TEMP_TIMER_IRQ_PRIO 14 // 14 = after hardware ISRs
-#endif
-
-// Ensure the default timer priority is somewhere between the STEP and TEMP priorities.
-// The STM32 framework defaults to interrupt 14 for all timers. This should be increased so that
-// timing-sensitive operations such as speaker output are note impacted by the long-running
-// temperature ISR. This must be defined in the platformio.ini file or the board's variant.h,
-// so that it will be consumed by framework code.
-#if !(TIM_IRQ_PRIO > STEP_TIMER_IRQ_PRIO && TIM_IRQ_PRIO < TEMP_TIMER_IRQ_PRIO)
- #error "Default timer interrupt priority is unspecified or set to a value which may degrade performance."
+ #define TEMP_TIMER_IRQ_PRIO TEMP_TIMER_IRQ_PRIO_DEFAULT
#endif
-
#if HAS_TMC_SW_SERIAL
#include <SoftwareSerial.h>
#ifndef SWSERIAL_TIMER_IRQ_PRIO
- #define SWSERIAL_TIMER_IRQ_PRIO 1
+ #define SWSERIAL_TIMER_IRQ_PRIO SWSERIAL_TIMER_IRQ_PRIO_DEFAULT
+ #endif
+#endif
+#if HAS_SERVOS
+ #include "Servo.h"
+ #ifndef SERVO_TIMER_IRQ_PRIO
+ #define SERVO_TIMER_IRQ_PRIO SERVO_TIMER_IRQ_PRIO_DEFAULT
+ #endif
+#endif
+#if ENABLED(SPEAKER)
+ // Ensure the default timer priority is somewhere between the STEP and TEMP priorities.
+ // The STM32 framework defaults to interrupt 14 for all timers. This should be increased so that
+ // timing-sensitive operations such as speaker output are not impacted by the long-running
+ // temperature ISR. This must be defined in the platformio.ini file or the board's variant.h,
+ // so that it will be consumed by framework code.
+ #if !(TIM_IRQ_PRIO > STEP_TIMER_IRQ_PRIO && TIM_IRQ_PRIO < TEMP_TIMER_IRQ_PRIO)
+ #error "Default timer interrupt priority is unspecified or set to a value which may degrade performance."
#endif
#endif
@@ -189,8 +204,9 @@ TIM_TypeDef * HAL_timer_device(const uint8_t timer_num) {
return nullptr;
}
-void SetSoftwareSerialTimerInterruptPriority() {
+void SetTimerInterruptPriorities() {
TERN_(HAS_TMC_SW_SERIAL, SoftwareSerial::setInterruptPriority(SWSERIAL_TIMER_IRQ_PRIO, 0));
+ TERN_(HAS_SERVOS, libServo::setInterruptPriority(SERVO_TIMER_IRQ_PRIO, 0));
}
#endif // ARDUINO_ARCH_STM32 && !STM32GENERIC
diff --git a/Marlin/src/HAL/STM32/timers.h b/Marlin/src/HAL/STM32/timers.h
index d6b333ef9cfc367abdaccc55b7e9bb632baff601..23a379973c5e06b63fa4ca915824816969364518 100644
--- a/Marlin/src/HAL/STM32/timers.h
+++ b/Marlin/src/HAL/STM32/timers.h
@@ -86,8 +86,9 @@ void HAL_timer_enable_interrupt(const uint8_t timer_num);
void HAL_timer_disable_interrupt(const uint8_t timer_num);
bool HAL_timer_interrupt_enabled(const uint8_t timer_num);
+// Configure timer priorities for peripherals such as Software Serial or Servos.
// Exposed here to allow all timer priority information to reside in timers.cpp
-void SetSoftwareSerialTimerInterruptPriority();
+void SetTimerInterruptPriorities();
//TIM_TypeDef* HAL_timer_device(const uint8_t timer_num); no need to be public for now. not public = not used externally