drm_hwcomposer: Add out-fence support

Add support for out-fences through the OUT_FENCE_PTR property.
Out-fences signal when their associated buffer may be read by a device.

Signed-off-by: Robert Foss <robert.foss@collabora.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/drmdisplaycompositor.cpp b/drmdisplaycompositor.cpp
index 75c1a7c..8936d08 100644
--- a/drmdisplaycompositor.cpp
+++ b/drmdisplaycompositor.cpp
@@ -602,6 +602,7 @@ int DrmDisplayCompositor::CommitFrame(DrmDisplayComposition *display_comp,
       display_comp->composition_planes();
   std::vector<DrmCompositionRegion> &pre_comp_regions =
       display_comp->pre_comp_regions();
+  uint64_t out_fences[drm_->crtcs().size()];
 
   DrmConnector *connector = drm_->GetConnectorForDisplay(display_);
   if (!connector) {
@@ -620,6 +621,16 @@ int DrmDisplayCompositor::CommitFrame(DrmDisplayComposition *display_comp,
     return -ENOMEM;
   }
 
+  if (crtc->out_fence_ptr_property().id() != 0) {
+    ret = drmModeAtomicAddProperty(pset, crtc->id(), crtc->out_fence_ptr_property().id(),
+                                   (uint64_t) &out_fences[crtc->pipe()]);
+    if (ret < 0) {
+      ALOGE("Failed to add OUT_FENCE_PTR property to pset: %d", ret);
+      drmModeAtomicFree(pset);
+      return ret;
+    }
+  }
+
   if (mode_.needs_modeset) {
     ret = drmModeAtomicAddProperty(pset, crtc->id(), crtc->mode_property().id(),
                                    mode_.blob_id) < 0 ||
@@ -818,6 +829,10 @@ out:
     mode_.needs_modeset = false;
   }
 
+  if (crtc->out_fence_ptr_property().id()) {
+    display_comp->set_out_fence((int) out_fences[crtc->pipe()]);
+  }
+
   return ret;
 }