ledc: Fix the usage of ledc_ls_timer_update and ledc_timer_rst

ledc_ls_timer_update is required only when CLK_DIV and DUTY_RES bits are changed.
Calling ledc_timer_rst while re-configure PWM frequency through ledc_set_freq can cause glitch in the signal

components/driver/ledc.c

@@ -276,7 +276,6 @@ esp_err_t ledc_timer_rst(ledc_mode_t speed_mode, ledc_timer_t timer_sel)
     LEDC_CHECK(p_ledc_obj[speed_mode] != NULL, LEDC_NOT_INIT, ESP_ERR_INVALID_STATE);
     portENTER_CRITICAL(&ledc_spinlock);
     ledc_hal_timer_rst(&(p_ledc_obj[speed_mode]->ledc_hal), timer_sel);
-    ledc_ls_timer_update(speed_mode, timer_sel);
     portEXIT_CRITICAL(&ledc_spinlock);
     return ESP_OK;
 }
@@ -288,7 +287,6 @@ esp_err_t ledc_timer_pause(ledc_mode_t speed_mode, ledc_timer_t timer_sel)
     LEDC_CHECK(p_ledc_obj[speed_mode] != NULL, LEDC_NOT_INIT, ESP_ERR_INVALID_STATE);
     portENTER_CRITICAL(&ledc_spinlock);
     ledc_hal_timer_pause(&(p_ledc_obj[speed_mode]->ledc_hal), timer_sel);
-    ledc_ls_timer_update(speed_mode, timer_sel);
     portEXIT_CRITICAL(&ledc_spinlock);
     return ESP_OK;
 }
@@ -300,7 +298,6 @@ esp_err_t ledc_timer_resume(ledc_mode_t speed_mode, ledc_timer_t timer_sel)
     LEDC_CHECK(p_ledc_obj[speed_mode] != NULL, LEDC_NOT_INIT, ESP_ERR_INVALID_STATE);
     portENTER_CRITICAL(&ledc_spinlock);
     ledc_hal_timer_resume(&(p_ledc_obj[speed_mode]->ledc_hal), timer_sel);
-    ledc_ls_timer_update(speed_mode, timer_sel);
     portEXIT_CRITICAL(&ledc_spinlock);
     return ESP_OK;
 }
@@ -581,9 +578,6 @@ static esp_err_t ledc_set_timer_div(ledc_mode_t speed_mode, ledc_timer_t timer_n
 
     /* The divisor is correct, we can write in the hardware. */
     ledc_timer_set(speed_mode, timer_num, div_param, duty_resolution, timer_clk_src);
-
-    /* Reset the timer. */
-    ledc_timer_rst(speed_mode, timer_num);
     return ESP_OK;
 
 error:
@@ -618,7 +612,12 @@ esp_err_t ledc_timer_config(const ledc_timer_config_t *timer_conf)
         ledc_hal_init(&(p_ledc_obj[speed_mode]->ledc_hal), speed_mode);
     }
 
-    return ledc_set_timer_div(speed_mode, timer_num, timer_conf->clk_cfg, freq_hz, duty_resolution);
+    esp_err_t ret = ledc_set_timer_div(speed_mode, timer_num, timer_conf->clk_cfg, freq_hz, duty_resolution);
+    if (ret == ESP_OK) {
+        /* Reset the timer. */
+        ledc_timer_rst(speed_mode, timer_num);
+    }
+    return ret;
 }
 
 esp_err_t ledc_set_pin(int gpio_num, ledc_mode_t speed_mode, ledc_channel_t ledc_channel)

components/driver/test/test_ledc.c

@@ -611,6 +611,7 @@ TEST_CASE("LEDC timer pause and resume", "[ledc]")
     printf("reset ledc timer\n");
     TEST_ESP_OK(ledc_timer_rst(test_speed_mode, LEDC_TIMER_0));
     vTaskDelay(100 / portTICK_PERIOD_MS);
+    count = wave_count(1000);
     TEST_ASSERT_UINT32_WITHIN(5, count, 5000);
     tear_testbench();
 }