From 48ef5736498fa676aa45d7f78b0feb11a68d74b5 Mon Sep 17 00:00:00 2001
From: kopecdav <david.kopecky@satoshilabs.com>
Date: Mon, 19 May 2025 11:51:54 +0200
Subject: [PATCH] refactor(core): remove recursion from power manager state
 machine automat [no changelog]

---
 .../prodtest/cmd/prodtest_power_manager.c     | 29 +++++------
 .../sys/power_manager/stm32u5/power_states.c  | 48 +++++++++++--------
 2 files changed, 40 insertions(+), 37 deletions(-)

diff --git a/core/embed/projects/prodtest/cmd/prodtest_power_manager.c b/core/embed/projects/prodtest/cmd/prodtest_power_manager.c
index ff7b32d5bd..63c1633721 100644
--- a/core/embed/projects/prodtest/cmd/prodtest_power_manager.c
+++ b/core/embed/projects/prodtest/cmd/prodtest_power_manager.c
@@ -328,17 +328,15 @@ void prodtest_pm_precharge(cli_t* cli) {
     return;
   }
 
-  // This test consider that the device is connected with USB and placed in
-  // ambient temperature. Battery will be charged with constanst current
-  // and precharge voltage is statically taken from the battery chaging curve
-  //
-  // It is expected that battery voltage during the charging is being lifted
-  // due to effect of internal resistance of the battery. So battery voltage
-  // will drop a bit after the charging is stopped.
+  // This test considers that the device is connected via USB and placed at
+  // ambient temperature. The battery will be charged with constant current,
+  // and the precharge voltage is statically derived from the battery charging
+  // curve.
 
-  // voltage while charging is being lifted due to charging with quite high
-  // charging current. When the test terminate by reaching the given woltage.
-  // The current and
+  // During charging, the voltage rises because of the relatively high charging
+  // current. When the test ends upon reaching the specified precharge voltage,
+  // the charging current is cut off, which can cause the battery voltage to
+  // fall slightly.
   float precharge_voltage_V = 3.45f;
 
   pm_charging_enable();
@@ -359,15 +357,12 @@ void prodtest_pm_precharge(cli_t* cli) {
       return;
     }
 
-    cli_trace(cli, "Battery voltage: %d.%03d V -> taret %d.%03d V",
-              (int)report.battery_voltage_v,
-              (int)(report.battery_voltage_v * 1000) % 1000,
+    cli_trace(cli, "Precharging the device to %d.%03d V",
               (int)precharge_voltage_V,
               (int)(precharge_voltage_V * 1000) % 1000);
-    cli_progress(cli, "%d.%03d %d.%03d", (int)report.battery_voltage_v,
-                 (int)(report.battery_voltage_v * 1000) % 1000,
-                 (int)precharge_voltage_V,
-                 (int)(precharge_voltage_V * 1000) % 1000);
+
+    // Print power manager report.
+    prodtest_pm_report(cli);
 
     if (cli_aborted(cli)) {
       cli_trace(cli, "aborted");
diff --git a/core/embed/sys/power_manager/stm32u5/power_states.c b/core/embed/sys/power_manager/stm32u5/power_states.c
index b355675f6f..085009972f 100644
--- a/core/embed/sys/power_manager/stm32u5/power_states.c
+++ b/core/embed/sys/power_manager/stm32u5/power_states.c
@@ -67,29 +67,37 @@ static const pm_state_handler_t state_handlers[] = {
 
 void pm_process_state_machine(void) {
   pm_driver_t* drv = &g_pm;
-  pm_internal_state_t old_state = drv->state;
+  pm_internal_state_t old_state;
+  pm_internal_state_t new_state;
 
-  // Get next state from current state's handler
-  pm_internal_state_t new_state = state_handlers[old_state].handle(drv);
+  // Loop until state machine converge to a stable state
+  while (true) {
+    // Get current state
+    old_state = drv->state;
 
-  // Handle state transition if needed
-  if (new_state != old_state) {
-    // Exit old state
-    if (state_handlers[old_state].exit != NULL) {
-      state_handlers[old_state].exit(drv);
+    // Call state handler to process the current state
+    new_state = state_handlers[old_state].handle(drv);
+
+    // Check if the state has changed
+    if (new_state != old_state) {
+      // Exit old state
+      if (state_handlers[old_state].exit != NULL) {
+        state_handlers[old_state].exit(drv);
+      }
+
+      // Update state
+      drv->state = new_state;
+      PM_SET_EVENT(drv->event_flags, PM_EVENT_STATE_CHANGED);
+
+      // Enter new state
+      if (state_handlers[new_state].enter != NULL) {
+        state_handlers[new_state].enter(drv);
+      }
+
+    } else {
+      // State has not changed, exit the loop
+      break;
     }
-
-    // Update state
-    drv->state = new_state;
-    PM_SET_EVENT(drv->event_flags, PM_EVENT_STATE_CHANGED);
-
-    // Enter new state
-    if (state_handlers[new_state].enter != NULL) {
-      state_handlers[new_state].enter(drv);
-    }
-
-    // Process state machine again as new state might trigger another transition
-    pm_process_state_machine();
   }
 }