ozone: Add atomic initialization path

ui/ozone/platform/drm/gpu/drm_device.cc

 // Copyright 2014 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 "ui/ozone/platform/drm/gpu/drm_device.h"
 
 #include <fcntl.h>
 #include <sys/mman.h>
 #include <unistd.h>
 #include <xf86drm.h>
@@ skipping 272 matching lines @@
     : device_path_(device_path),
       file_(file.Pass()),
       page_flip_manager_(new PageFlipManager()) {
 }
 
 DrmDevice::~DrmDevice() {
   if (watcher_)
     watcher_->Shutdown();
 }
 
-bool DrmDevice::Initialize() {
+bool DrmDevice::Initialize(bool use_atomic) {
   // Ignore devices that cannot perform modesetting.
   if (!CanQueryForResources(file_.GetPlatformFile())) {
     VLOG(2) << "Cannot query for resources for '" << device_path_.value()
             << "'";
     return false;
   }
 
 #if defined(USE_DRM_ATOMIC)
-  plane_manager_.reset(new HardwareDisplayPlaneManagerAtomic());
-#else
-  plane_manager_.reset(new HardwareDisplayPlaneManagerLegacy());
+  // Use atomic only if the build, kernel & flags all allow it.
+  if (use_atomic && SetCapability(DRM_CLIENT_CAP_ATOMIC, 1))
+    plane_manager_.reset(new HardwareDisplayPlaneManagerAtomic());
 #endif  // defined(USE_DRM_ATOMIC)
+
+  if (!plane_manager_)
+    plane_manager_.reset(new HardwareDisplayPlaneManagerLegacy());
   if (!plane_manager_->Initialize(this)) {
     LOG(ERROR) << "Failed to initialize the plane manager for "
                << device_path_.value();
     plane_manager_.reset();
     return false;
   }
 
   return true;
 }
 
@@ skipping 240 matching lines @@
   return !drmIoctl(file_.GetPlatformFile(), DRM_IOCTL_GEM_CLOSE,
                    &close_request);
 }
 
 bool DrmDevice::CommitProperties(drmModePropertySet* properties,
                                  uint32_t flags,
                                  bool is_sync,
                                  const PageFlipCallback& callback) {
 #if defined(USE_DRM_ATOMIC)
   flags |= DRM_MODE_PAGE_FLIP_EVENT;
-  scoped_ptr<PageFlipPayload> payload(
-      new PageFlipPayload(base::ThreadTaskRunnerHandle::Get(), callback));
   uint64_t id = page_flip_manager_->GetNextId();
-  if (!drmModePropertySetCommit(file_.GetPlatformFile(), flags, payload.get(),
-                                properties)) {
+  if (!drmModePropertySetCommit(file_.GetPlatformFile(), flags,
+                                reinterpret_cast<void*>(id), properties)) {
     page_flip_manager_->RegisterCallback(id, callback);
 
     // If the flip was requested synchronous or if no watcher has been installed
     // yet, then synchronously handle the page flip events.
     if (is_sync || !watcher_) {
       TRACE_EVENT1("drm", "OnDrmEvent", "socket", file_.GetPlatformFile());
 
       ProcessDrmEvent(
           file_.GetPlatformFile(),
           base::Bind(&PageFlipManager::OnPageFlip, page_flip_manager_));
@@ skipping 41 matching lines @@
     b.push_back(lut[i].b);
   }
 
   DCHECK(file_.IsValid());
   TRACE_EVENT0("drm", "DrmDevice::SetGamma");
   return (drmModeCrtcSetGamma(file_.GetPlatformFile(), crtc_id, r.size(), &r[0],
                               &g[0], &b[0]) == 0);
 }
 
 }  // namespace ui