ledc: Fix FADE_NO_WAIT mode concurrency problem.

Add test cases for fade concurrency issue and fade timing check.

Closes https://github.com/espressif/esp-idf/issues/6710

components/driver/include/driver/ledc.h

@@ -420,7 +420,8 @@ void ledc_fade_func_uninstall(void);
  *        Other duty operations will have to wait until the fade operation has finished.
  * @param speed_mode Select the LEDC channel group with specified speed mode. Note that not all targets support high speed mode.
  * @param channel LEDC channel number
- * @param fade_mode Whether to block until fading done.
+ * @param fade_mode Whether to block until fading done. See ledc_types.h ledc_fade_mode_t for more info.
+ *        Note that this function will not return until fading to the target duty if LEDC_FADE_WAIT_DONE mode is selected.
  *
  * @return
  *     - ESP_OK Success

components/driver/ledc.c

@@ -216,7 +216,7 @@ esp_err_t ledc_timer_set(ledc_mode_t speed_mode, ledc_timer_t timer_sel, uint32_
 static IRAM_ATTR esp_err_t ledc_duty_config(ledc_mode_t speed_mode, ledc_channel_t channel, int hpoint_val, int duty_val,
         ledc_duty_direction_t duty_direction, uint32_t duty_num, uint32_t duty_cycle, uint32_t duty_scale)
 {
-    portENTER_CRITICAL(&ledc_spinlock);
+    portENTER_CRITICAL_SAFE(&ledc_spinlock);
     if (hpoint_val >= 0) {
         ledc_hal_set_hpoint(&(p_ledc_obj[speed_mode]->ledc_hal), channel, hpoint_val);
     }
@@ -228,7 +228,7 @@ static IRAM_ATTR esp_err_t ledc_duty_config(ledc_mode_t speed_mode, ledc_channel
     ledc_hal_set_duty_cycle(&(p_ledc_obj[speed_mode]->ledc_hal), channel, duty_cycle);
     ledc_hal_set_duty_scale(&(p_ledc_obj[speed_mode]->ledc_hal), channel, duty_scale);
     ledc_ls_channel_update(speed_mode, channel);
-    portEXIT_CRITICAL(&ledc_spinlock);
+    portEXIT_CRITICAL_SAFE(&ledc_spinlock);
     return ESP_OK;
 }
 
@@ -802,9 +802,9 @@ void IRAM_ATTR ledc_fade_isr(void *arg)
             ledc_calc_fade_end_channel(&intr_status, &channel);
 
             // clear interrupt
-            portENTER_CRITICAL(&ledc_spinlock);
+            portENTER_CRITICAL_ISR(&ledc_spinlock);
             ledc_hal_clear_fade_end_intr_status(&(p_ledc_obj[speed_mode]->ledc_hal), channel);
-            portEXIT_CRITICAL(&ledc_spinlock);
+            portEXIT_CRITICAL_ISR(&ledc_spinlock);
 
             if (s_ledc_fade_rec[speed_mode][channel] == NULL) {
                 //fade object not initialized yet.
@@ -854,9 +854,9 @@ void IRAM_ATTR ledc_fade_isr(void *arg)
                     1,
                     0);
             }
-            portENTER_CRITICAL(&ledc_spinlock);
+            portENTER_CRITICAL_ISR(&ledc_spinlock);
             ledc_hal_set_duty_start(&(p_ledc_obj[speed_mode]->ledc_hal), channel, true);
-            portEXIT_CRITICAL(&ledc_spinlock);
+            portEXIT_CRITICAL_ISR(&ledc_spinlock);
         }
     }
     if (HPTaskAwoken == pdTRUE || cb_yield) {
@@ -999,7 +999,10 @@ static void _ledc_fade_start(ledc_mode_t speed_mode, ledc_channel_t channel, led
     ledc_enable_intr_type(speed_mode, channel, LEDC_INTR_FADE_END);
     ledc_update_duty(speed_mode, channel);
     if (fade_mode == LEDC_FADE_WAIT_DONE) {
-        xSemaphoreTake(s_ledc_fade_rec[speed_mode][channel]->ledc_fade_sem, portMAX_DELAY);
+        // Waiting for fade done
+        _ledc_fade_hw_acquire(speed_mode, channel);
+        // Release hardware to support next time fade configure
+        _ledc_fade_hw_release(speed_mode, channel);
     }
 }
 
@@ -1041,7 +1044,6 @@ esp_err_t ledc_fade_start(ledc_mode_t speed_mode, ledc_channel_t channel, ledc_f
     LEDC_CHECK(p_ledc_obj[speed_mode] != NULL, LEDC_NOT_INIT, ESP_ERR_INVALID_STATE);
     _ledc_fade_hw_acquire(speed_mode, channel);
     _ledc_fade_start(speed_mode, channel, fade_mode);
-    _ledc_fade_hw_release(speed_mode, channel);
     return ESP_OK;
 }
 
@@ -1089,12 +1091,10 @@ esp_err_t ledc_set_duty_and_update(ledc_mode_t speed_mode, ledc_channel_t channe
     LEDC_ARG_CHECK(hpoint <= LEDC_HPOINT_VAL_MAX, "hpoint");
     LEDC_CHECK(p_ledc_obj[speed_mode] != NULL, LEDC_NOT_INIT, ESP_ERR_INVALID_STATE);
     LEDC_CHECK(ledc_fade_channel_init_check(speed_mode, channel) == ESP_OK, LEDC_FADE_INIT_ERROR_STR, ESP_FAIL);
-    _ledc_op_lock_acquire(speed_mode, channel);
     _ledc_fade_hw_acquire(speed_mode, channel);
     ledc_duty_config(speed_mode, channel, hpoint, duty, 1, 0, 0, 0);
     ledc_update_duty(speed_mode, channel);
     _ledc_fade_hw_release(speed_mode, channel);
-    _ledc_op_lock_release(speed_mode, channel);
     return ESP_OK;
 }
 
@@ -1110,9 +1110,6 @@ esp_err_t ledc_set_fade_time_and_start(ledc_mode_t speed_mode, ledc_channel_t ch
     _ledc_fade_hw_acquire(speed_mode, channel);
     _ledc_set_fade_with_time(speed_mode, channel, target_duty, max_fade_time_ms);
     _ledc_fade_start(speed_mode, channel, fade_mode);
-    if (fade_mode == LEDC_FADE_WAIT_DONE) {
-        _ledc_fade_hw_release(speed_mode, channel);
-    }
     _ledc_op_lock_release(speed_mode, channel);
     return ESP_OK;
 }
@@ -1131,9 +1128,6 @@ esp_err_t ledc_set_fade_step_and_start(ledc_mode_t speed_mode, ledc_channel_t ch
     _ledc_fade_hw_acquire(speed_mode, channel);
     _ledc_set_fade_with_step(speed_mode, channel, target_duty, scale, cycle_num);
     _ledc_fade_start(speed_mode, channel, fade_mode);
-    if (fade_mode == LEDC_FADE_WAIT_DONE) {
-        _ledc_fade_hw_release(speed_mode, channel);
-    }
     _ledc_op_lock_release(speed_mode, channel);
     return ESP_OK;
 }

components/driver/test/test_ledc.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -34,6 +34,8 @@
 #define HIGHEST_LIMIT 10000
 #define LOWEST_LIMIT -10000
 
+#define TEST_PWM_FREQ 2000
+
 #if SOC_LEDC_SUPPORT_HS_MODE
 #define TEST_SPEED_MODE LEDC_HIGH_SPEED_MODE
 #define SPEED_MODE_LIST {LEDC_HIGH_SPEED_MODE, LEDC_LOW_SPEED_MODE}
@@ -63,17 +65,31 @@ static ledc_timer_config_t create_default_timer_config(void)
     ledc_time_config.speed_mode = TEST_SPEED_MODE;
     ledc_time_config.duty_resolution = LEDC_TIMER_13_BIT;
     ledc_time_config.timer_num = LEDC_TIMER_0;
-    ledc_time_config.freq_hz = 2000;
+    ledc_time_config.freq_hz = TEST_PWM_FREQ;
     ledc_time_config.clk_cfg = LEDC_USE_APB_CLK;
     return ledc_time_config;
 }
 
+static void fade_setup(void)
+{
+    ledc_channel_config_t ledc_ch_config = initialize_channel_config();
+    ledc_ch_config.duty = 0;
+    ledc_timer_config_t ledc_time_config = create_default_timer_config();
+
+    TEST_ESP_OK(ledc_channel_config(&ledc_ch_config));
+    TEST_ESP_OK(ledc_timer_config(&ledc_time_config));
+    vTaskDelay(5 / portTICK_RATE_MS);
+
+    //initialize fade service
+    TEST_ESP_OK(ledc_fade_func_install(0));
+}
+
 static void timer_duty_set_get(ledc_mode_t speed_mode, ledc_channel_t channel, uint32_t duty)
 {
     TEST_ESP_OK(ledc_set_duty(speed_mode, channel, duty));
     TEST_ESP_OK(ledc_update_duty(speed_mode, channel));
-    vTaskDelay(1000 / portTICK_RATE_MS);
-    TEST_ASSERT_EQUAL_INT32(ledc_get_duty(speed_mode, channel), duty);
+    vTaskDelay(100 / portTICK_RATE_MS);
+    TEST_ASSERT_EQUAL_INT32(duty, ledc_get_duty(speed_mode, channel));
 }
 
 // use logic analyzer to view
@@ -302,9 +318,9 @@ TEST_CASE("LEDC memory leak test", "[ledc]")
     TEST_ESP_OK(ledc_stop(ledc_time_config.speed_mode, LEDC_CHANNEL_0, 0));
 }
 
-// the duty need to be detected by waveform given by the logic analyzer
-// can't get it directly, so set it "ignore"
-TEST_CASE("LEDC set and get dut(with logic analyzer)", "[ledc][ignore]")
+// duty should be manually checked from the waveform using a logic analyzer
+// this test is enabled only for testting the settings
+TEST_CASE("LEDC set and get duty", "[ledc]")
 {
     ledc_timer_t timer_list[4] = {LEDC_TIMER_0, LEDC_TIMER_1, LEDC_TIMER_2, LEDC_TIMER_3};
     ledc_mode_t speed_mode_list[LEDC_SPEED_MODE_MAX] = SPEED_MODE_LIST;
@@ -315,61 +331,111 @@ TEST_CASE("LEDC set and get dut(with logic analyzer)", "[ledc][ignore]")
     }
 }
 
-TEST_CASE("LEDC fade with time(logic analyzer)", "[ledc][ignore]")
+TEST_CASE("LEDC fade with time", "[ledc]")
 {
     const ledc_mode_t test_speed_mode = TEST_SPEED_MODE;
-    ledc_channel_config_t ledc_ch_config = initialize_channel_config();
-    ledc_ch_config.duty = 0;
-    ledc_timer_config_t ledc_time_config = create_default_timer_config();
-
-    TEST_ESP_OK(ledc_channel_config(&ledc_ch_config));
-    TEST_ESP_OK(ledc_timer_config(&ledc_time_config));
+    fade_setup();
 
-    //initialize fade service
-    TEST_ESP_OK(ledc_fade_func_install(0));
-
-    TEST_ESP_OK(ledc_set_fade_with_time(test_speed_mode, LEDC_CHANNEL_0, 4000, 1000));
+    TEST_ESP_OK(ledc_set_fade_with_time(test_speed_mode, LEDC_CHANNEL_0, 4000, 200));
     TEST_ESP_OK(ledc_fade_start(test_speed_mode, LEDC_CHANNEL_0, LEDC_FADE_WAIT_DONE));
-    // TODO: allows for 5% deviation here due to driver code (IDF-2099)
-    vTaskDelay(1050 / portTICK_RATE_MS);
-    TEST_ASSERT_EQUAL_INT32(ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0), 4000);
+    TEST_ASSERT_EQUAL_INT32(4000, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
 
-    TEST_ESP_OK(ledc_set_fade_with_time(test_speed_mode, LEDC_CHANNEL_0, 0, 1000));
+    TEST_ESP_OK(ledc_set_fade_with_time(test_speed_mode, LEDC_CHANNEL_0, 0, 200));
     TEST_ESP_OK(ledc_fade_start(test_speed_mode, LEDC_CHANNEL_0, LEDC_FADE_NO_WAIT));
-    vTaskDelay(1050 / portTICK_RATE_MS);
-    TEST_ASSERT_EQUAL_INT32(ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0), 0);
+    // duty should not be too far from initial value
+    TEST_ASSERT_INT32_WITHIN(20, 4000, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
+    vTaskDelay(210 / portTICK_RATE_MS);
+    TEST_ASSERT_EQUAL_INT32(0, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
 
-    //deinitial fade service
+    //deinitialize fade service
     ledc_fade_func_uninstall();
 }
 
-TEST_CASE("LEDC fade with step(logic analyzer)", "[ledc][ignore]")
+TEST_CASE("LEDC fade with step", "[ledc]")
 {
     const ledc_mode_t test_speed_mode = TEST_SPEED_MODE;
-    ledc_channel_config_t ledc_ch_config = initialize_channel_config();
-    ledc_ch_config.duty = 0;
-    ledc_timer_config_t ledc_time_config = create_default_timer_config();
+    fade_setup();
 
-    TEST_ESP_OK(ledc_channel_config(&ledc_ch_config));
-    TEST_ESP_OK(ledc_timer_config(&ledc_time_config));
-
-    //initialize fade service.
-    TEST_ESP_OK(ledc_fade_func_install(0));
-
-    TEST_ESP_OK(ledc_set_fade_with_step(test_speed_mode, LEDC_CHANNEL_0, 4000, 2, 1));
+    TEST_ESP_OK(ledc_set_fade_with_step(test_speed_mode, LEDC_CHANNEL_0, 4000, 4, 1));
     TEST_ESP_OK(ledc_fade_start(test_speed_mode, LEDC_CHANNEL_0, LEDC_FADE_WAIT_DONE));
-    vTaskDelay(1050 / portTICK_RATE_MS);
-    TEST_ASSERT_EQUAL_INT32(ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0), 4000);
+    TEST_ASSERT_EQUAL_INT32(4000, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
 
-    TEST_ESP_OK(ledc_set_fade_with_step(test_speed_mode, LEDC_CHANNEL_0, 0, 4, 2));
+    TEST_ESP_OK(ledc_set_fade_with_step(test_speed_mode, LEDC_CHANNEL_0, 0, 4, 1));
     TEST_ESP_OK(ledc_fade_start(test_speed_mode, LEDC_CHANNEL_0, LEDC_FADE_NO_WAIT));
-    vTaskDelay(1050 / portTICK_RATE_MS);
-    TEST_ASSERT_EQUAL_INT32(ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0), 0);
+    // duty should not be too far from initial value
+    TEST_ASSERT_INT32_WITHIN(20, 4000, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
+    vTaskDelay(525 / portTICK_RATE_MS);
+    TEST_ASSERT_EQUAL_INT32(0, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
 
     //scaler=0 check
     TEST_ASSERT(ledc_set_fade_with_step(test_speed_mode, LEDC_CHANNEL_0, 4000, 0, 1) == ESP_ERR_INVALID_ARG);
 
-    //deinitial fade service
+    //deinitialize fade service
+    ledc_fade_func_uninstall();
+}
+
+TEST_CASE("LEDC fast switching duty with fade_wait_done", "[ledc]")
+{
+    const ledc_mode_t test_speed_mode = TEST_SPEED_MODE;
+    fade_setup();
+
+    // fade function will block until fading to the target duty
+    int64_t fade_start, fade_stop;
+    fade_start = esp_timer_get_time();
+    TEST_ESP_OK(ledc_set_fade_with_time(test_speed_mode, LEDC_CHANNEL_0, 4000, 200));
+    TEST_ESP_OK(ledc_fade_start(test_speed_mode, LEDC_CHANNEL_0, LEDC_FADE_WAIT_DONE));
+    TEST_ASSERT_EQUAL_INT32(4000, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
+    TEST_ESP_OK(ledc_set_fade_with_time(test_speed_mode, LEDC_CHANNEL_0, 1000, 150));
+    TEST_ESP_OK(ledc_fade_start(test_speed_mode, LEDC_CHANNEL_0, LEDC_FADE_WAIT_DONE));
+    TEST_ASSERT_EQUAL_INT32(1000, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
+    fade_stop = esp_timer_get_time();
+    int time_ms = (fade_stop - fade_start) / 1000;
+    TEST_ASSERT_TRUE(fabs(time_ms - 350) < 20);
+
+    // next duty update will not take place until last fade reaches its target duty
+    TEST_ESP_OK(ledc_set_fade_with_time(test_speed_mode, LEDC_CHANNEL_0, 4000, 200));
+    TEST_ESP_OK(ledc_fade_start(test_speed_mode, LEDC_CHANNEL_0, LEDC_FADE_WAIT_DONE));
+    TEST_ASSERT_EQUAL_INT32(4000, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
+    TEST_ESP_OK(ledc_set_duty(test_speed_mode, LEDC_CHANNEL_0, 500));
+    TEST_ESP_OK(ledc_update_duty(test_speed_mode, LEDC_CHANNEL_0));
+    vTaskDelay(5 / portTICK_RATE_MS);
+    TEST_ASSERT_EQUAL_INT32(500, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
+
+    //deinitialize fade service
+    ledc_fade_func_uninstall();
+}
+
+TEST_CASE("LEDC fast switching duty with fade_no_wait", "[ledc]")
+{
+    const ledc_mode_t test_speed_mode = TEST_SPEED_MODE;
+    fade_setup();
+
+    // fade function returns immediately, but next fade still needs to wait for last fade ends
+    int64_t fade_start, first_fade_complete;
+    fade_start = esp_timer_get_time();
+    TEST_ESP_OK(ledc_set_fade_with_time(test_speed_mode, LEDC_CHANNEL_0, 4000, 200));
+    TEST_ESP_OK(ledc_fade_start(test_speed_mode, LEDC_CHANNEL_0, LEDC_FADE_NO_WAIT));
+    TEST_ASSERT_LESS_THAN(4000, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
+    TEST_ESP_OK(ledc_set_fade_with_time(test_speed_mode, LEDC_CHANNEL_0, 1000, 150));
+    TEST_ESP_OK(ledc_fade_start(test_speed_mode, LEDC_CHANNEL_0, LEDC_FADE_NO_WAIT));
+    first_fade_complete = esp_timer_get_time();
+    // duty should not be too far from first fade target duty
+    TEST_ASSERT_INT32_WITHIN(20, 4000, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
+    int time_ms = (first_fade_complete - fade_start) / 1000;
+    TEST_ASSERT_TRUE(fabs(time_ms - 200) < 20);
+    vTaskDelay(158 / portTICK_RATE_MS);
+    TEST_ASSERT_EQUAL_INT32(1000, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
+
+    // next duty update will not take place until last fade reaches its target duty
+    TEST_ESP_OK(ledc_set_fade_with_time(test_speed_mode, LEDC_CHANNEL_0, 4000, 200));
+    TEST_ESP_OK(ledc_fade_start(test_speed_mode, LEDC_CHANNEL_0, LEDC_FADE_NO_WAIT));
+    TEST_ASSERT_LESS_THAN(4000, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
+    TEST_ESP_OK(ledc_set_duty(test_speed_mode, LEDC_CHANNEL_0, 500));
+    TEST_ESP_OK(ledc_update_duty(test_speed_mode, LEDC_CHANNEL_0));
+    vTaskDelay(5 / portTICK_RATE_MS);
+    TEST_ASSERT_EQUAL_INT32(500, ledc_get_duty(test_speed_mode, LEDC_CHANNEL_0));
+
+    //deinitialize fade service
     ledc_fade_func_uninstall();
 }
 
@@ -424,7 +490,7 @@ TEST_CASE("LEDC timer set", "[ledc][test_env=UT_T1_LEDC]")
     count = wave_count(1000);
     TEST_ASSERT_UINT32_WITHIN(10, count, freq_get);
 
-    //set timer 3 as 500Hz, use APB_CLK
+    //set timer 0 as 500Hz, use APB_CLK
     TEST_ESP_OK(ledc_timer_set(test_speed_mode, LEDC_TIMER_0, 5000, 13, LEDC_APB_CLK));
     TEST_ESP_OK(ledc_timer_rst(test_speed_mode, LEDC_TIMER_0));
     TEST_ASSERT_EQUAL_INT32(ledc_get_freq(test_speed_mode, LEDC_TIMER_0), 500);