Use the current state when resuming.

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 <X11/Xlib.h>
 #include <X11/extensions/dpms.h>
 #include <X11/extensions/Xrandr.h>
 
@@ skipping 586 matching lines @@
   Display* display = base::MessagePumpAuraX11::GetDefaultXDisplay();
   CHECK(display != NULL);
   XGrabServer(display);
   Window window = DefaultRootWindow(display);
   XRRScreenResources* screen = GetScreenResourcesAndRecordUMA(display, window);
   CHECK(screen != NULL);
 
   OutputSnapshot outputs[2] = { {0}, {0} };
   connected_output_count_ =
       GetDualOutputs(display, screen, &outputs[0], &outputs[1]);
-  output_state_ =
-      InferCurrentState(display, screen, outputs, connected_output_count_);
+
+  if (all_displays && power_on) {
+    // Resume all displays using the current state.
+    if (EnterState(display,
+                   screen,
+                   window,
+                   output_state_,
+                   outputs,
+                   connected_output_count_)) {
+      // Force the DPMS on since the driver doesn't always detect that it should
+      // turn on.
+      CHECK(DPMSEnable(display));
+      CHECK(DPMSForceLevel(display, DPMSModeOn));
+
+      XRRFreeScreenResources(screen);
+      XUngrabServer(display);
+      return true;
+    }
+  }
 
   RRCrtc crtc = None;
   // Set the CRTCs based on whether we want to turn the power on or off and
   // select the outputs to operate on by name or all_displays.
   for (int i = 0; i < connected_output_count_; ++i) {
     if (all_displays || outputs[i].is_internal || power_on) {
       const int x = 0;
       const int y = outputs[i].y;
       RROutput output = outputs[i].output;
       RRMode mode = None;
       if (power_on) {
         mode = (STATE_DUAL_MIRROR == output_state_) ?
             outputs[i].mirror_mode : outputs[i].native_mode;
       } else if (connected_output_count_ > 1 && !all_displays &&
-                 STATE_DUAL_MIRROR != output_state_ && outputs[i].is_internal) {
+                 outputs[i].is_internal) {
         // Workaround for crbug.com/148365: leave internal display in native
         // mode so user can move cursor (and hence windows) onto internal
         // display even when dimmed
         mode = outputs[i].native_mode;
       }
       crtc = GetNextCrtcAfter(display, screen, output, crtc);
 
-      // The values we are setting are already from the cache so no update
-      // required.
       ConfigureCrtc(display,
                     screen,
                     crtc,
                     x,
                     y,
                     mode,
                     output);
       success = true;
     }
   }
@@ skipping 297 matching lines @@
 // static
 RRMode OutputConfigurator::GetOutputNativeMode(
     const XRROutputInfo* output_info) {
   if (output_info->nmode <= 0)
     return None;
 
   return output_info->modes[0];
 }
 
 }  // namespace chromeos