Backlight off should not transition to dim or off states

powerd.cc

 // Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "power_manager/powerd.h"
 
 #include <gdk/gdkx.h>
 #include <stdint.h>
 #include <X11/extensions/dpms.h>
 #include <X11/keysym.h>
@@ skipping 316 matching lines @@
   }
   GenerateMetricsOnIdleEvent(is_idle, idle_time_ms);
   SetIdleState(idle_time_ms);
   if (!is_idle && offset_ms_ != 0)
     SetIdleOffset(0, kIdleNormal);
 }
 
 void Daemon::SetIdleState(int64 idle_time_ms) {
   bool changed_brightness = false;
   if (idle_time_ms >= suspend_ms_) {
-    LOG(INFO) << "state = kIdleSuspend";
     // Note: currently this state doesn't do anything.  But it can be possibly
     // useful in future development.  For example, if we want to implement fade
     // from suspend, we would want to have this state to make sure the backlight
     // is set to zero when suspended.
-    changed_brightness =
-        backlight_controller_->SetPowerState(BACKLIGHT_SUSPENDED);
-    idle_state_ = kIdleSuspend;
-    Suspend();
+    if (backlight_controller_->SetPowerState(BACKLIGHT_SUSPENDED)) {
+      idle_state_ = kIdleSuspend;
+      LOG(INFO) << "state = kIdleSuspend";
+      changed_brightness = true;
+      Suspend();
+    }
   } else if (idle_time_ms >= off_ms_) {
-    LOG(INFO) << "state = kIdleScreenOff";
-    changed_brightness =
-        backlight_controller_->SetPowerState(BACKLIGHT_IDLE_OFF);
-    idle_state_ = kIdleScreenOff;
+    if (backlight_controller_->SetPowerState(BACKLIGHT_IDLE_OFF)) {
+      idle_state_ = kIdleScreenOff;
+      LOG(INFO) << "state = kIdleScreenOff";
+      changed_brightness = true;
+    }
   } else if (idle_time_ms >= dim_ms_) {
-    LOG(INFO) << "state = kIdleDim";
-    changed_brightness = backlight_controller_->SetPowerState(BACKLIGHT_DIM);
-    idle_state_ = kIdleDim;
+    if (backlight_controller_->SetPowerState(BACKLIGHT_DIM)) {
+      idle_state_ = kIdleDim;
+      LOG(INFO) << "state = kIdleDim";
+      changed_brightness = true;
+    }
   } else if (idle_state_ != kIdleNormal) {
-    LOG(INFO) << "state = kIdleNormal";
-    changed_brightness =
-        backlight_controller_->SetPowerState(BACKLIGHT_ACTIVE_ON);
-    if (idle_state_ == kIdleSuspend) {
-      util::CreateStatusFile(FilePath(run_dir_).Append(util::kUserActiveFile));
-      suspender_.CancelSuspend();
+    if (backlight_controller_->SetPowerState(BACKLIGHT_ACTIVE_ON)) {
+      if (idle_state_ == kIdleSuspend) {
+        util::CreateStatusFile(FilePath(run_dir_)
+                              .Append(util::kUserActiveFile));
+        suspender_.CancelSuspend();
+      }
+      idle_state_ = kIdleNormal;
+      LOG(INFO) << "state = kIdleNormal";
+      changed_brightness = true;
     }
-    idle_state_ = kIdleNormal;
   }
   if (idle_time_ms >= lock_ms_ && util::LoggedIn() &&
       idle_state_ != kIdleSuspend) {
     locker_.LockScreen();
   }
 
   if (changed_brightness)
     SendBrightnessChangedSignal(false);  // user_initiated=false
 }
 
@@ skipping 310 matching lines @@
   dbus_g_proxy_send(proxy.gproxy(), signal, NULL);
   dbus_message_unref(signal);
 }
 
 void Daemon::HandleResume() {
   file_tagger_.HandleResumeEvent();
   backlight_controller_->SetPowerState(BACKLIGHT_ACTIVE_ON);
 }
 
 }  // namespace power_manager