stm32/powerctrl: Enable EIWUP to ensure RTC wakes device from standby.
@@ -390,6 +390,12 @@ void powerctrl_enter_standby_mode(void) {
// enable previously-enabled RTC interrupts
RTC->CR |= save_irq_bits;
+ #if defined(STM32F7)
+ // Enable the internal (eg RTC) wakeup sources
+ // See Errata 2.2.2 "Wakeup from Standby mode when the back-up SRAM regulator is enabled"
+ PWR->CSR1 |= PWR_CSR1_EIWUP;
+ #endif
+
// enter standby mode
HAL_PWR_EnterSTANDBYMode();
// we never return; MCU is reset on exit from standby
