esp_timer: Add Test case when set_alarm needs set timer < now_time

components/esp32/test/test_esp_timer.c

@@ -4,6 +4,7 @@
 #include <sys/time.h>
 #include <sys/param.h>
 #include "unity.h"
+#include "soc/frc_timer_reg.h"
 #include "esp_timer.h"
 #include "esp_heap_caps.h"
 #include "freertos/FreeRTOS.h"
@@ -779,3 +780,21 @@ TEST_CASE("esp_timer_impl_set_alarm and using start_once do not lead that the Sy
 }
 
 #endif // !defined(CONFIG_FREERTOS_UNICORE) && defined(CONFIG_ESP32_DPORT_WORKAROUND)
+
+TEST_CASE("Test case when esp_timer_impl_set_alarm needs set timer < now_time", "[esp_timer]")
+{
+    REG_WRITE(FRC_TIMER_LOAD_REG(1), 0);
+    esp_timer_impl_advance(50331648); // 0xefffffff/80 = 50331647
+
+    ets_delay_us(2);
+
+    portDISABLE_INTERRUPTS();
+    esp_timer_impl_set_alarm(50331647);
+    uint32_t alarm_reg = REG_READ(FRC_TIMER_ALARM_REG(1));
+    uint32_t count_reg = REG_READ(FRC_TIMER_COUNT_REG(1));
+    portENABLE_INTERRUPTS();
+
+    const uint32_t offset = 80 * 2; // s_timer_ticks_per_us
+    printf("alarm_reg = 0x%x, count_reg 0x%x\n", alarm_reg, count_reg);
+    TEST_ASSERT(alarm_reg <= (count_reg + offset));
+}