[Ozone-GBM] Handle GPU crashes

ui/ozone/platform/dri/screen_manager.cc

Index: ui/ozone/platform/dri/screen_manager.cc
diff --git a/ui/ozone/platform/dri/screen_manager.cc b/ui/ozone/platform/dri/screen_manager.cc
index 0a8af0fc662a8efa3388aa14ea1941228f2cf838..5e96759398b77c0a448754cdc9d982c7c04f5eb4 100644
--- a/ui/ozone/platform/dri/screen_manager.cc
+++ b/ui/ozone/platform/dri/screen_manager.cc
@@ -32,6 +32,17 @@ ScreenManager::ScreenManager(DriWrapper* dri,
 ScreenManager::~ScreenManager() {
 }
 
+void ScreenManager::AddDisplayController(uint32_t crtc, uint32_t connector) {
+  HardwareDisplayControllers::iterator it = FindDisplayController(crtc);
+  if (it != controllers_.end()) {
+    LOG(WARNING) << "Display controller (crtc=" << crtc << ") already present.";

[alexst (slow to review), 2014/09/04 14:44:45]

Do you expect this to be a regular frequent occurrence? If so does it make sense
to check this at call site? If it's meant as an unforeseen event, we should
DCHECK maybe?

[dnicoara, 2014/09/04 15:12:07]

This is a by-product of having to support a forced initialization for
content_shell and GPU process startup timing on CrOS. So it should really only
happen at start-up or when the GPU process crashes (and is restarted).

Though I did forget to add a comment, since this should be turned into a DCHECK
once display configuration is saner on the async path.

+    return;
+  }
+
+  controllers_.push_back(new HardwareDisplayController(
+      dri_, scoped_ptr<CrtcState>(new CrtcState(dri_, crtc, connector))));
+}
+
 void ScreenManager::RemoveDisplayController(uint32_t crtc) {
   HardwareDisplayControllers::iterator it = FindDisplayController(crtc);
   if (it != controllers_.end()) {
@@ -48,48 +59,34 @@ bool ScreenManager::ConfigureDisplayController(uint32_t crtc,
                                                const drmModeModeInfo& mode) {
   gfx::Rect modeset_bounds(origin, GetModeSize(mode));
   HardwareDisplayControllers::iterator it = FindDisplayController(crtc);
-  HardwareDisplayController* controller = NULL;
-  if (it != controllers_.end()) {
-    controller = *it;
-    // If nothing changed just enable the controller. Note, we perform an exact
-    // comparison on the mode since the refresh rate may have changed.
-    if (SameMode(mode, controller->get_mode()) &&
-        origin == controller->origin() && !controller->IsDisabled())
-      return controller->Enable();
-
-    // Either the mode or the location of the display changed, so exit mirror
-    // mode and configure the display independently. If the caller still wants
-    // mirror mode, subsequent calls configuring the other controllers will
-    // restore mirror mode.
-    if (controller->IsMirrored()) {
-      controller =
-          new HardwareDisplayController(dri_, controller->RemoveCrtc(crtc));
-      controllers_.push_back(controller);
-      it = --controllers_.end();
-    }
-
-    HardwareDisplayControllers::iterator mirror =
-        FindActiveDisplayControllerByLocation(modeset_bounds);
-    // Handle mirror mode.
-    if (mirror != controllers_.end() && it != mirror)
-      return HandleMirrorMode(it, mirror, crtc, connector);
-  } else {
-    HardwareDisplayControllers::iterator mirror =
-        FindActiveDisplayControllerByLocation(modeset_bounds);
-    if (mirror != controllers_.end()) {
-      (*mirror)->AddCrtc(
-          scoped_ptr<CrtcState>(new CrtcState(dri_, crtc, connector)));
-      return (*mirror)->Enable();
-    }
-  }
-
-  if (!controller) {
-    controller = new HardwareDisplayController(
-        dri_,
-        scoped_ptr<CrtcState>(new CrtcState(dri_, crtc, connector)));
+  DCHECK(controllers_.end() != it) << "Display controller (crtc=" << crtc
+                                   << ") doesn't exist.";
+
+  HardwareDisplayController* controller = *it;
+  controller = *it;
+  // If nothing changed just enable the controller. Note, we perform an exact
+  // comparison on the mode since the refresh rate may have changed.
+  if (SameMode(mode, controller->get_mode()) &&
+      origin == controller->origin() && !controller->IsDisabled())
+    return controller->Enable();
+
+  // Either the mode or the location of the display changed, so exit mirror
+  // mode and configure the display independently. If the caller still wants
+  // mirror mode, subsequent calls configuring the other controllers will
+  // restore mirror mode.
+  if (controller->IsMirrored()) {
+    controller =
+        new HardwareDisplayController(dri_, controller->RemoveCrtc(crtc));
     controllers_.push_back(controller);
+    it = --controllers_.end();
   }
 
+  HardwareDisplayControllers::iterator mirror =
+      FindActiveDisplayControllerByLocation(modeset_bounds);
+  // Handle mirror mode.
+  if (mirror != controllers_.end() && it != mirror)
+    return HandleMirrorMode(it, mirror, crtc, connector);
+
   return ModesetDisplayController(controller, origin, mode);
 }
 
@@ -168,6 +165,8 @@ void ScreenManager::ForceInitializationOfPrimaryDisplay() {
                       dpms->prop_id,
                       DRM_MODE_DPMS_ON);
 
+  AddDisplayController(displays[0]->crtc()->crtc_id,
+                       displays[0]->connector()->connector_id);
   ConfigureDisplayController(displays[0]->crtc()->crtc_id,
                              displays[0]->connector()->connector_id,
                              gfx::Point(),