Implement support for monitor suspend.

chromeos/display/output_configurator.cc

 // Copyright (c) 2012 The Chromium 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 "chromeos/display/output_configurator.h"
 
 #include <cmath>
 
 #include <X11/Xatom.h>
 #include <X11/Xlib.h>
@@ skipping 751 matching lines @@
       XRRFreeScreenResources(screen);
       XUngrabServer(display);
 
       chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
           SetIsProjecting(is_projecting);
     }
     // Ignore the case of RR_UnkownConnection.
   }
 
   // Sets the timer for NotifyOnDisplayChanged().  When an output state change
-  // is issued, several notifications chould arrive and NotifyOnDisplayChanged()
+  // is issued, several notifications should arrive and NotifyOnDisplayChanged()
   // should be called once for the last one.  The timer could lead at most a few
-  // handreds milliseconds of delay for the notification, but it would be
+  // hundreds of milliseconds of delay for the notification, but it would be
   // unrecognizable for users.
   if (notification_timer_.get()) {
     notification_timer_->Reset();
   } else {
     notification_timer_.reset(new base::OneShotTimer<OutputConfigurator>());
     notification_timer_->Start(
         FROM_HERE,
         base::TimeDelta::FromMilliseconds(kNotificationTimerDelayMs),
         this,
         &OutputConfigurator::NotifyOnDisplayChanged);
   }
   return true;
 }
 
 void OutputConfigurator::AddObserver(Observer* observer) {
   observers_.AddObserver(observer);
 }
 
 void OutputConfigurator::RemoveObserver(Observer* observer) {
   observers_.RemoveObserver(observer);
 }
 
 // static
 bool OutputConfigurator::IsInternalOutputName(const std::string& name) {
   return name.find(kInternal_LVDS) == 0 || name.find(kInternal_eDP) == 0;
 }
 
+void OutputConfigurator::SuspendDisplays() {
+  // Turn displays on before suspend. At this point, the backlight is off,
+  // so we turn on the internal display so that we can resume directly into
+  // "on" state. This greatly reduces resume times.
+  ScreenPowerSet(true, true);
+  // We need to make sure that the monitor configuration we just did actually
+  // completes before we return, because otherwise the X message could be
+  // racing with the HandleSuspendReadiness message.
+  XSync(base::MessagePumpAuraX11::GetDefaultXDisplay(), 0);
+}
+
 void OutputConfigurator::NotifyOnDisplayChanged() {
   notification_timer_.reset();
   FOR_EACH_OBSERVER(Observer, observers_, OnDisplayModeChanged());
 }
 
 std::vector<OutputSnapshot> OutputConfigurator::GetDualOutputs(
     Display* display,
     XRRScreenResources* screen) {
   std::vector<OutputSnapshot> outputs;
   XRROutputInfo* one_info = NULL;
@@ skipping 476 matching lines @@
 // static
 RRMode OutputConfigurator::GetOutputNativeMode(
     const XRROutputInfo* output_info) {
   if (output_info->nmode <= 0)
     return None;
 
   return output_info->modes[0];
 }
 
 }  // namespace chromeos