[ledc] Fix high-pressure crash & recovery (#14720)

esphome/components/ledc/ledc_output.cpp

@@ -5,6 +5,10 @@
 
 #include <driver/ledc.h>
 #include <cinttypes>
+#include <esp_private/periph_ctrl.h>
+#if !defined(SOC_LEDC_SUPPORT_FADE_STOP)
+#include <hal/ledc_ll.h>
+#endif
 
 #define CLOCK_FREQUENCY 80e6f
 
@@ -16,10 +20,10 @@
 
 static const uint8_t SETUP_ATTEMPT_COUNT_MAX = 5;
 
-namespace esphome {
-namespace ledc {
+namespace esphome::ledc {
 
 static const char *const TAG = "ledc.output";
+static bool ledc_peripheral_reset_done = false;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
 static const int MAX_RES_BITS = LEDC_TIMER_BIT_MAX - 1;
 #if SOC_LEDC_SUPPORT_HS_MODE
@@ -32,6 +36,28 @@ inline ledc_mode_t get_speed_mode(uint8_t channel) { return channel < 8 ? LEDC_H
 inline ledc_mode_t get_speed_mode(uint8_t) { return LEDC_LOW_SPEED_MODE; }
 #endif
 
+#if !defined(SOC_LEDC_SUPPORT_FADE_STOP)
+// Classic ESP32 (currently the only target without SOC_LEDC_SUPPORT_FADE_STOP) can block in
+// ledc_ll_set_duty_start() while duty_start is set. We check the same conf1.duty_start bit here
+// to defer updates and avoid entering IDF's unbounded wait loop.
+//
+// This intentionally depends on the classic ESP32 LEDC register layout used by IDF's own LL HAL.
+// If another target without SOC_LEDC_SUPPORT_FADE_STOP is introduced, revisit this helper.
+static_assert(
+#if defined(CONFIG_IDF_TARGET_ESP32)
+    true,
+#else
+    false,
+#endif
+    "LEDC duty_start pending check assumes classic ESP32 register layout; "
+    "re-evaluate for this target");
+
+static bool ledc_duty_update_pending(ledc_mode_t speed_mode, ledc_channel_t chan_num) {
+  auto *hw = LEDC_LL_GET_HW();
+  return hw->channel_group[speed_mode].channel[chan_num].conf1.duty_start != 0;
+}
+#endif
+
 float ledc_max_frequency_for_bit_depth(uint8_t bit_depth) {
   return static_cast<float>(CLOCK_FREQUENCY) / static_cast<float>(1 << bit_depth);
 }
@@ -105,21 +131,40 @@ void LEDCOutput::write_state(float state) {
   const uint32_t max_duty = (uint32_t(1) << this->bit_depth_) - 1;
   const float duty_rounded = roundf(state * max_duty);
   auto duty = static_cast<uint32_t>(duty_rounded);
+  if (duty == this->last_duty_) {
+    return;
+  }
+
   ESP_LOGV(TAG, "Setting duty: %" PRIu32 " on channel %u", duty, this->channel_);
   auto speed_mode = get_speed_mode(this->channel_);
   auto chan_num = static_cast<ledc_channel_t>(this->channel_ % 8);
   int hpoint = ledc_angle_to_htop(this->phase_angle_, this->bit_depth_);
   if (duty == max_duty) {
     ledc_stop(speed_mode, chan_num, 1);
+    this->last_duty_ = duty;
   } else if (duty == 0) {
     ledc_stop(speed_mode, chan_num, 0);
+    this->last_duty_ = duty;
   } else {
+#if !defined(SOC_LEDC_SUPPORT_FADE_STOP)
+    if (ledc_duty_update_pending(speed_mode, chan_num)) {
+      ESP_LOGV(TAG, "Skipping LEDC duty update on channel %u while previous duty_start is still set", this->channel_);
+      return;
+    }
+#endif
     ledc_set_duty_with_hpoint(speed_mode, chan_num, duty, hpoint);
     ledc_update_duty(speed_mode, chan_num);
+    this->last_duty_ = duty;
   }
 }
 
 void LEDCOutput::setup() {
+  if (!ledc_peripheral_reset_done) {
+    ESP_LOGV(TAG, "Resetting LEDC peripheral to clear stale state after reboot");
+    periph_module_reset(PERIPH_LEDC_MODULE);
+    ledc_peripheral_reset_done = true;
+  }
+
   auto speed_mode = get_speed_mode(this->channel_);
   auto timer_num = static_cast<ledc_timer_t>((this->channel_ % 8) / 2);
   auto chan_num = static_cast<ledc_channel_t>(this->channel_ % 8);
@@ -207,12 +252,12 @@ void LEDCOutput::update_frequency(float frequency) {
   this->status_clear_error();
 
   // re-apply duty
+  this->last_duty_ = UINT32_MAX;
   this->write_state(this->duty_);
 }
 
 uint8_t next_ledc_channel = 0;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
-}  // namespace ledc
-}  // namespace esphome
+}  // namespace esphome::ledc
 
 #endif

esphome/components/ledc/ledc_output.h

@@ -4,11 +4,11 @@
 #include "esphome/core/hal.h"
 #include "esphome/core/automation.h"
 #include "esphome/components/output/float_output.h"
+#include <cstdint>
 
 #ifdef USE_ESP32
 
-namespace esphome {
-namespace ledc {
+namespace esphome::ledc {
 
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
 extern uint8_t next_ledc_channel;
@@ -39,6 +39,7 @@ class LEDCOutput : public output::FloatOutput, public Component {
   float phase_angle_{0.0f};
   float frequency_{};
   float duty_{0.0f};
+  uint32_t last_duty_{UINT32_MAX};
   bool initialized_ = false;
 };
 
@@ -56,7 +57,6 @@ template<typename... Ts> class SetFrequencyAction : public Action<Ts...> {
   LEDCOutput *parent_;
 };
 
-}  // namespace ledc
-}  // namespace esphome
+}  // namespace esphome::ledc
 
 #endif