Atomic: Don’t keep track of Cursor planes

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

Index: ui/ozone/platform/drm/gpu/crtc_controller.cc
diff --git a/ui/ozone/platform/drm/gpu/crtc_controller.cc b/ui/ozone/platform/drm/gpu/crtc_controller.cc
index 8871a1719fc8facc88149ac2093ce576ee7cf6ff..1cae85b4c9be6edbe11468e51cf6387d7602187b 100644
--- a/ui/ozone/platform/drm/gpu/crtc_controller.cc
+++ b/ui/ozone/platform/drm/gpu/crtc_controller.cc
@@ -15,9 +15,7 @@ namespace ui {
 CrtcController::CrtcController(const scoped_refptr<DrmDevice>& drm,
                                uint32_t crtc,
                                uint32_t connector)
-    : drm_(drm),
-      crtc_(crtc),
-      connector_(connector) {}
+    : drm_(drm), cursor_plane_(nullptr), crtc_(crtc), connector_(connector) {}
 
 CrtcController::~CrtcController() {
   if (!is_disabled_) {
@@ -146,13 +144,35 @@ bool CrtcController::MoveCursor(const gfx::Point& location) {
 bool CrtcController::ResetCursor() {
   uint32_t handle = 0;
   gfx::Size size;
-
+#if defined(USE_DRM_ATOMIC)
+  if (!cursor_plane_) {
+    const ScopedVector<HardwareDisplayPlane>& all_planes =
+        drm_->plane_manager()->planes();
+    for (auto* plane : all_planes) {
+      if (plane->CanUseForCrtc(crtc_) && !plane->owning_crtc() &&

[dnicoara, 2015/08/20 14:22:45]

I think that the plane allocation logic will serve cursor planes with the rest
of the planes during HDCM::AssignOverlayPlanes() which will cause this to return
no cursor planes. We don't want to end up in a situation where we're asked to
show a cursor but fail because the cursor plane is displaying some different
overlay.

This should take the simpler approach of always assuming the cursor plane is
allocated to the CRTC.

[kalyank, 2015/08/20 16:36:17]

Removed the extra check related to owned crtc.

[kalyank, 2015/08/20 16:36:18]

Done.

+          (plane->type() == HardwareDisplayPlane::Cursor)) {
+        cursor_plane_ = plane;
+      }
+    }
+  }
+#endif
   if (cursor_buffer_) {
     handle = cursor_buffer_->GetHandle();
     size = cursor_buffer_->GetSize();
   }
 
   bool status = drm_->SetCursor(crtc_, handle, size);
+  if (cursor_plane_) {
+    if (status && handle) {
+      cursor_plane_->set_owning_crtc(crtc_);
+      cursor_plane_->set_in_use(true);
+    } else {
+      cursor_plane_->set_owning_crtc(0);
+      cursor_plane_->set_in_use(false);
+      cursor_plane_ = nullptr;
+    }
+  }
+
   if (!status) {
     PLOG(ERROR) << "drmModeSetCursor: device " << drm_->device_path().value()
                 << " crtc " << crtc_ << " handle " << handle << " size "