drm_hwcomposer: Add fallback to client for layers flattening
Google recommends to delegate composition to GLES instead of HWC when
screen isn't updating to conserve power, as stated on page
https://source.android.com/devices/graphics/implement-hwc.
Current implementation of hwcomposer has flattening of layers if after
some time there were no updates of frames, but it uses writeback
connector. Not every device has a support of writeback feature, so
some sort of fallback should be provided.
It is possible to fallback to client composition in case if writeback
isn't available. This is used to reduce power consumption since
squashing layers into a single layer on GPU and then using that buffer
is more efficient than loading drm device.
Signed-off-by: Roman Kovalivskyi <roman.kovalivskyi@globallogic.com>
diff --git a/drmhwctwo.cpp b/drmhwctwo.cpp
index e2c943a..a4a8187 100644
--- a/drmhwctwo.cpp
+++ b/drmhwctwo.cpp
@@ -208,6 +208,12 @@
HandleInitialHotplugState(device.get());
break;
}
+ case HWC2::Callback::Refresh: {
+ for (std::pair<const hwc2_display_t, DrmHwcTwo::HwcDisplay> &d :
+ displays_)
+ d.second.RegisterRefreshCallback(data, function);
+ break;
+ }
case HWC2::Callback::Vsync: {
for (std::pair<const hwc2_display_t, DrmHwcTwo::HwcDisplay> &d :
displays_)
@@ -310,6 +316,15 @@
return HWC2::Error::None;
}
+void DrmHwcTwo::HwcDisplay::RegisterRefreshCallback(
+ hwc2_callback_data_t data, hwc2_function_pointer_t func) {
+ supported(__func__);
+ auto hook = reinterpret_cast<HWC2_PFN_REFRESH>(func);
+ compositor_.SetRefreshCallback([data, hook](int display) {
+ hook(data, static_cast<hwc2_display_t>(display));
+ });
+}
+
HWC2::Error DrmHwcTwo::HwcDisplay::AcceptDisplayChanges() {
supported(__func__);
for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_)
@@ -900,51 +915,57 @@
int client_start = -1, client_size = 0;
- for (std::pair<const uint32_t, DrmHwcTwo::HwcLayer *> &l : z_map) {
- if (!HardwareSupportsLayerType(l.second->sf_type()) ||
- !importer_->CanImportBuffer(l.second->buffer()) ||
- color_transform_hint_ != HAL_COLOR_TRANSFORM_IDENTITY ||
- (l.second->RequireScalingOrPhasing() &&
- resource_manager_->ForcedScalingWithGpu())) {
- if (client_start < 0)
- client_start = l.first;
- client_size = (l.first - client_start) + 1;
- }
- }
-
- int extra_client = (z_map.size() - client_size) - avail_planes;
- if (extra_client > 0) {
- int start = 0, steps;
- if (client_size != 0) {
- int prepend = std::min(client_start, extra_client);
- int append = std::min(int(z_map.size() - (client_start + client_size)),
- extra_client);
- start = client_start - prepend;
- client_size += extra_client;
- steps = 1 + std::min(std::min(append, prepend),
- int(z_map.size()) - (start + client_size));
- } else {
- client_size = extra_client;
- steps = 1 + z_map.size() - extra_client;
- }
-
- gpu_pixops = INT_MAX;
- for (int i = 0; i < steps; i++) {
- uint32_t po = CalcPixOps(z_map, start + i, client_size);
- if (po < gpu_pixops) {
- gpu_pixops = po;
- client_start = start + i;
+ if (compositor_.ShouldFlattenOnClient()) {
+ client_start = 0;
+ client_size = z_map.size();
+ MarkValidated(z_map, client_start, client_size);
+ } else {
+ for (std::pair<const uint32_t, DrmHwcTwo::HwcLayer *> &l : z_map) {
+ if (!HardwareSupportsLayerType(l.second->sf_type()) ||
+ !importer_->CanImportBuffer(l.second->buffer()) ||
+ color_transform_hint_ != HAL_COLOR_TRANSFORM_IDENTITY ||
+ (l.second->RequireScalingOrPhasing() &&
+ resource_manager_->ForcedScalingWithGpu())) {
+ if (client_start < 0)
+ client_start = l.first;
+ client_size = (l.first - client_start) + 1;
}
}
- }
- MarkValidated(z_map, client_start, client_size);
+ int extra_client = (z_map.size() - client_size) - avail_planes;
+ if (extra_client > 0) {
+ int start = 0, steps;
+ if (client_size != 0) {
+ int prepend = std::min(client_start, extra_client);
+ int append = std::min(int(z_map.size() - (client_start + client_size)),
+ extra_client);
+ start = client_start - prepend;
+ client_size += extra_client;
+ steps = 1 + std::min(std::min(append, prepend),
+ int(z_map.size()) - (start + client_size));
+ } else {
+ client_size = extra_client;
+ steps = 1 + z_map.size() - extra_client;
+ }
- if (CreateComposition(true) != HWC2::Error::None) {
- ++total_stats_.failed_kms_validate_;
- gpu_pixops = total_pixops;
- client_size = z_map.size();
- MarkValidated(z_map, 0, client_size);
+ gpu_pixops = INT_MAX;
+ for (int i = 0; i < steps; i++) {
+ uint32_t po = CalcPixOps(z_map, start + i, client_size);
+ if (po < gpu_pixops) {
+ gpu_pixops = po;
+ client_start = start + i;
+ }
+ }
+ }
+
+ MarkValidated(z_map, client_start, client_size);
+
+ if (CreateComposition(true) != HWC2::Error::None) {
+ ++total_stats_.failed_kms_validate_;
+ gpu_pixops = total_pixops;
+ client_size = z_map.size();
+ MarkValidated(z_map, 0, client_size);
+ }
}
*num_types = client_size;