drm_hwcomposer: Support assigning planes in ValidateDisplay

In order to assign planes to layers in ValidateDisplay, testing compositing with a DRM atomic modeset test is needed as PresentDisplay is too late. This means most of PresentDisplay needs to be run from ValidateDisplay, so refactor PresentDisplay and plumb a test flag down the stack.

Signed-off-by Rob Herring <[email protected]>

---
Based on my GL comp removal work. Adding atomic test path turned out to be easier than using the Planner directly.

 drmdisplaycompositor.cpp |  4 +-
 drmdisplaycompositor.h   |  2 +-
 drmhwctwo.cpp            | 79 ++++++++++++++++++++++++++++++++++------
 drmhwctwo.h              |  1 +
 4 files changed, 73 insertions(+), 13 deletions(-)

drmdisplaycompositor.cpp +0 -0

index 2f9f6c6772da..ceee6b1a4bd6 100644

drmdisplaycompositor.h +0 -0

   int Composite();
   void Dump(std::ostringstream *out) const;
 

drmhwctwo.cpp +0 -0

index deaf14363e8c..19f73e721154 100644

drmhwctwo.cpp +7 -1

   std::vector<DrmCompositionDisplayLayersMap> layers_map;
   layers_map.emplace_back();
   DrmCompositionDisplayLayersMap &map = layers_map.back();

@@ -494,7 +493,13 @@ HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
   uint32_t client_z_order = 0;
   std::map<uint32_t, DrmHwcTwo::HwcLayer *> z_map;
   for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_) {
-    switch (l.second.validated_type()) {
+    HWC2::Composition comp_type;
+    if (test)
+      comp_type = l.second.sf_type();
+    else
+      comp_type = l.second.validated_type();
+
+    switch (comp_type) {
       case HWC2::Composition::Device:
         z_map.emplace(std::make_pair(l.second.z_order(), &l.second));
         break;

drmhwctwo.cpp +19 -7

   // now that they're ordered by z, add them to the composition
   for (std::pair<const uint32_t, DrmHwcTwo::HwcLayer *> &l : z_map) {
     DrmHwcLayer layer;

@@ -521,10 +530,6 @@ HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
     }
     map.layers.emplace_back(std::move(layer));
   }
-  if (map.layers.empty()) {
-    *retire_fence = -1;
-    return HWC2::Error::None;
-  }
 
   std::unique_ptr<DrmDisplayComposition> composition =
       compositor_.CreateComposition();

@@ -555,13 +560,29 @@ HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
     i = overlay_planes.erase(i);
   }
 
-  AddFenceToRetireFence(composition->take_out_fence());
+  if (!test)
+    AddFenceToRetireFence(composition->take_out_fence());
 
-  ret = compositor_.ApplyComposition(std::move(composition));
+  ret = compositor_.ApplyComposition(std::move(composition), test);
   if (ret) {
     ALOGE("Failed to apply the frame composition ret=%d", ret);
     return HWC2::Error::BadParameter;
   }
+  return HWC2::Error::None;
+}
+
+HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
+  supported(__func__);
+  HWC2::Error ret;
+
+  ret = CreateComposition(false);
+  if (ret == HWC2::Error::BadLayer) {
+      // Can we really have no client or device layers?
+      *retire_fence = -1;
+      return HWC2::Error::None;
+  }
+  if (ret != HWC2::Error::None)
+    return ret;
 
   // The retire fence returned here is for the last frame, so return it and
   // promote the next retire fence

@@ -586,7 +607,7 @@ HWC2::Error DrmHwcTwo::HwcDisplay::SetActiveConfig(hwc2_config_t config) {
       compositor_.CreateComposition();
   composition->Init(drm_, crtc_, importer_.get(), planner_.get(), frame_no_);
   int ret = composition->SetDisplayMode(*mode);
-  ret = compositor_.ApplyComposition(std::move(composition));
+  ret = compositor_.ApplyComposition(std::move(composition), false);
   if (ret) {
     ALOGE("Failed to queue dpms composition on %d", ret);
     return HWC2::Error::BadConfig;

drmhwctwo.cpp +36 -0

   if (ret) {
     ALOGE("Failed to apply the dpms composition ret=%d", ret);
     return HWC2::Error::BadParameter;

@@ -683,11 +704,47 @@ HWC2::Error DrmHwcTwo::HwcDisplay::SetVsyncEnabled(int32_t enabled) {
 HWC2::Error DrmHwcTwo::HwcDisplay::ValidateDisplay(uint32_t *num_types,
                                                    uint32_t *num_requests) {
   supported(__func__);
+  size_t plane_count = 0;
   *num_types = 0;
   *num_requests = 0;
+  size_t avail_planes = primary_planes_.size() + overlay_planes_.size();
+
+  HWC2::Error ret;
+
+  for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_)
+    l.second.set_validated_type(HWC2::Composition::Invalid);
+
+  ret = CreateComposition(true);
+  if (ret != HWC2::Error::None)
+    // Assume the test failed due to overlay planes
+    avail_planes = 1;
+
+  std::map<uint32_t, DrmHwcTwo::HwcLayer *> z_map;
+  for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_) {
+    if (l.second.sf_type() == HWC2::Composition::Device)
+        z_map.emplace(std::make_pair(l.second.z_order(), &l.second));
+  }
+
+  /*
+   * If more layers then planes, save one plane
+   * for client composited layers
+   */
+  if (avail_planes < layers_.size())
+       avail_planes--;
+
+  for (std::pair<const uint32_t, DrmHwcTwo::HwcLayer *> &l : z_map) {
+    if (!avail_planes--)
+        break;
+    l.second->set_validated_type(HWC2::Composition::Device);
+  }
+
   for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_) {
     DrmHwcTwo::HwcLayer &layer = l.second;
     switch (layer.sf_type()) {
+      case HWC2::Composition::Device:
+        if (layer.validated_type() == HWC2::Composition::Device)
+          break;
+        // fall thru
       case HWC2::Composition::SolidColor:
       case HWC2::Composition::Cursor:
       case HWC2::Composition::Sideband:

drmhwctwo.h +0 -0

index 0490e2ac7f85..bbf55d9a08bc 100644

drmhwctwo.h +0 -1

     HWC2::Error PresentDisplay(int32_t *retire_fence);
     HWC2::Error SetActiveConfig(hwc2_config_t config);
     HWC2::Error SetClientTarget(buffer_handle_t target, int32_t acquire_fence,
--

2.17.0

Hey Rob,

Quoted 22 lines · Rob Herring

In order to assign planes to layers in ValidateDisplay, testing compositing with a DRM atomic modeset test is needed as PresentDisplay is too late. This means most of PresentDisplay needs to be run from ValidateDisplay, so refactor PresentDisplay and plumb a test flag down the stack.

Signed-off-by Rob Herring <[email protected]>

---
Based on my GL comp removal work. Adding atomic test path turned out to be easier than using the Planner directly.

 drmdisplaycompositor.cpp |  4 +-
 drmdisplaycompositor.h   |  2 +-
 drmhwctwo.cpp            | 79 ++++++++++++++++++++++++++++++++++------
 drmhwctwo.h              |  1 +
 4 files changed, 73 insertions(+), 13 deletions(-)

drmdisplaycompositor.cpp +0 -0

index 2f9f6c6772da..ceee6b1a4bd6 100644

drmdisplaycompositor.cpp void DrmDisplayCompositor::ApplyFrame( · line 472

Quoted 5 lines

drmdisplaycompositor.cpp +1 -1

@@ -469,7 +469,7 @@ void DrmDisplayCompositor::ApplyFrame(
 }
 
 int DrmDisplayCompositor::ApplyComposition(
-    std::unique_ptr<DrmDisplayComposition> composition) {
+    std::unique_ptr<DrmDisplayComposition> composition, bool test) {

Since ApplyComposition just calls CommitFrame which already has test support, can we reuse that for a TestComposition function?

drmdisplaycompositor.cpp int DrmDisplayCompositor::ApplyComposition( · line 485

Quoted 9 lines

drmdisplaycompositor.cpp +2 -0

   int ret = 0;
   switch (composition->type()) {
     case DRM_COMPOSITION_TYPE_FRAME:

@@ -481,6 +481,8 @@ int DrmDisplayCompositor::ApplyComposition(
           ALOGE("Commit test failed for display %d, FIXME", display_);
           return ret;
         }
+        if (test)
+          return 0;

Then we could also drop this hunk.

drmdisplaycompositor.h class DrmDisplayCompositor { · line 46

Quoted 13 lines

drmdisplaycompositor.cpp +0 -0

       }
 
       ApplyFrame(std::move(composition), ret);

drmdisplaycompositor.h +1 -1

index ed46873c3409..7c5ebb005dc4 100644
@@ -43,7 +43,7 @@ class DrmDisplayCompositor {
   int Init(DrmResources *drm, int display);
 
   std::unique_ptr<DrmDisplayComposition> CreateComposition() const;
-  int ApplyComposition(std::unique_ptr<DrmDisplayComposition> composition);
+  int ApplyComposition(std::unique_ptr<DrmDisplayComposition> composition, bool test);

And this one.

Quoted 8 lines

drmdisplaycompositor.h +0 -0

   int Composite();
   void Dump(std::ostringstream *out) const;
 

drmhwctwo.cpp +0 -0

index deaf14363e8c..19f73e721154 100644

drmhwctwo.cpp void DrmHwcTwo::HwcDisplay::AddFenceToRetireFence(int fd) { · line 483

Quoted 6 lines

drmhwctwo.cpp +1 -2

@@ -480,8 +480,7 @@ void DrmHwcTwo::HwcDisplay::AddFenceToRetireFence(int fd) {
   }
 }
 
-HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
-  supported(__func__);
+HWC2::Error DrmHwcTwo::HwcDisplay::CreateComposition(bool test) {

This is called CreateComposition, but it also tests and even commits. If this only sets up the DrmDisplayComposition, we could just have the test and commit in Validate/Present respectively and drop the flag. Unfortunately it also uses and mutates the layer state, and moving that into Present/Validate from here looks more difficult.

Quoted 19 lines

drmhwctwo.cpp +7 -1

   std::vector<DrmCompositionDisplayLayersMap> layers_map;
   layers_map.emplace_back();
   DrmCompositionDisplayLayersMap &map = layers_map.back();

@@ -494,7 +493,13 @@ HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
   uint32_t client_z_order = 0;
   std::map<uint32_t, DrmHwcTwo::HwcLayer *> z_map;
   for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_) {
-    switch (l.second.validated_type()) {
+    HWC2::Composition comp_type;
+    if (test)
+      comp_type = l.second.sf_type();
+    else
+      comp_type = l.second.validated_type();
+
+    switch (comp_type) {
       case HWC2::Composition::Device:
         z_map.emplace(std::make_pair(l.second.z_order(), &l.second));
         break;

drmhwctwo.cpp HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) { · line 521

Quoted 7 lines

drmhwctwo.cpp +4 -0

@@ -510,6 +515,10 @@ HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
   if (use_client_layer)
     z_map.emplace(std::make_pair(client_z_order, &client_layer_));
 
+  if (z_map.empty())
+    return HWC2::Error::BadLayer;
+
+

Extra newline.

Quoted 56 lines

drmhwctwo.cpp +19 -7

   // now that they're ordered by z, add them to the composition
   for (std::pair<const uint32_t, DrmHwcTwo::HwcLayer *> &l : z_map) {
     DrmHwcLayer layer;

@@ -521,10 +530,6 @@ HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
     }
     map.layers.emplace_back(std::move(layer));
   }
-  if (map.layers.empty()) {
-    *retire_fence = -1;
-    return HWC2::Error::None;
-  }
 
   std::unique_ptr<DrmDisplayComposition> composition =
       compositor_.CreateComposition();

@@ -555,13 +560,29 @@ HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
     i = overlay_planes.erase(i);
   }
 
-  AddFenceToRetireFence(composition->take_out_fence());
+  if (!test)
+    AddFenceToRetireFence(composition->take_out_fence());
 
-  ret = compositor_.ApplyComposition(std::move(composition));
+  ret = compositor_.ApplyComposition(std::move(composition), test);
   if (ret) {
     ALOGE("Failed to apply the frame composition ret=%d", ret);
     return HWC2::Error::BadParameter;
   }
+  return HWC2::Error::None;
+}
+
+HWC2::Error DrmHwcTwo::HwcDisplay::PresentDisplay(int32_t *retire_fence) {
+  supported(__func__);
+  HWC2::Error ret;
+
+  ret = CreateComposition(false);
+  if (ret == HWC2::Error::BadLayer) {
+      // Can we really have no client or device layers?
+      *retire_fence = -1;
+      return HWC2::Error::None;
+  }
+  if (ret != HWC2::Error::None)
+    return ret;
 
   // The retire fence returned here is for the last frame, so return it and
   // promote the next retire fence

@@ -586,7 +607,7 @@ HWC2::Error DrmHwcTwo::HwcDisplay::SetActiveConfig(hwc2_config_t config) {
       compositor_.CreateComposition();
   composition->Init(drm_, crtc_, importer_.get(), planner_.get(), frame_no_);
   int ret = composition->SetDisplayMode(*mode);
-  ret = compositor_.ApplyComposition(std::move(composition));
+  ret = compositor_.ApplyComposition(std::move(composition), false);
   if (ret) {
     ALOGE("Failed to queue dpms composition on %d", ret);
     return HWC2::Error::BadConfig;

drmhwctwo.cpp HWC2::Error DrmHwcTwo::HwcDisplay::SetPowerMode(int32_t mode_in) { · line 690

Quoted 5 lines

drmhwctwo.cpp +1 -1

@@ -666,7 +687,7 @@ HWC2::Error DrmHwcTwo::HwcDisplay::SetPowerMode(int32_t mode_in) {
       compositor_.CreateComposition();
   composition->Init(drm_, crtc_, importer_.get(), planner_.get(), frame_no_);
   composition->SetDpmsMode(dpms_value);
-  int ret = compositor_.ApplyComposition(std::move(composition));
+  int ret = compositor_.ApplyComposition(std::move(composition), false);

With a TestComposition we can drop the two hunks here.

Quoted 56 lines

drmhwctwo.cpp +36 -0

   if (ret) {
     ALOGE("Failed to apply the dpms composition ret=%d", ret);
     return HWC2::Error::BadParameter;

@@ -683,11 +704,47 @@ HWC2::Error DrmHwcTwo::HwcDisplay::SetVsyncEnabled(int32_t enabled) {
 HWC2::Error DrmHwcTwo::HwcDisplay::ValidateDisplay(uint32_t *num_types,
                                                    uint32_t *num_requests) {
   supported(__func__);
+  size_t plane_count = 0;
   *num_types = 0;
   *num_requests = 0;
+  size_t avail_planes = primary_planes_.size() + overlay_planes_.size();
+
+  HWC2::Error ret;
+
+  for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_)
+    l.second.set_validated_type(HWC2::Composition::Invalid);
+
+  ret = CreateComposition(true);
+  if (ret != HWC2::Error::None)
+    // Assume the test failed due to overlay planes
+    avail_planes = 1;
+
+  std::map<uint32_t, DrmHwcTwo::HwcLayer *> z_map;
+  for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_) {
+    if (l.second.sf_type() == HWC2::Composition::Device)
+        z_map.emplace(std::make_pair(l.second.z_order(), &l.second));
+  }
+
+  /*
+   * If more layers then planes, save one plane
+   * for client composited layers
+   */
+  if (avail_planes < layers_.size())
+       avail_planes--;
+
+  for (std::pair<const uint32_t, DrmHwcTwo::HwcLayer *> &l : z_map) {
+    if (!avail_planes--)
+        break;
+    l.second->set_validated_type(HWC2::Composition::Device);
+  }
+
   for (std::pair<const hwc2_layer_t, DrmHwcTwo::HwcLayer> &l : layers_) {
     DrmHwcTwo::HwcLayer &layer = l.second;
     switch (layer.sf_type()) {
+      case HWC2::Composition::Device:
+        if (layer.validated_type() == HWC2::Composition::Device)
+          break;
+        // fall thru
       case HWC2::Composition::SolidColor:
       case HWC2::Composition::Cursor:
       case HWC2::Composition::Sideband:

drmhwctwo.h +0 -0

index 0490e2ac7f85..bbf55d9a08bc 100644

drmhwctwo.h class DrmHwcTwo : public hwc2_device_t { · line 174

Quoted 4 lines

drmhwctwo.h +1 -0

@@ -171,6 +171,7 @@ class DrmHwcTwo : public hwc2_device_t {
                                    float *min_luminance);
     HWC2::Error GetReleaseFences(uint32_t *num_elements, hwc2_layer_t *layers,
                                  int32_t *fences);
+    HWC2::Error CreateComposition(bool test);

This is more of a private function than a HWC2 hook.

Quoted 6 lines

drmhwctwo.h +0 -1

     HWC2::Error PresentDisplay(int32_t *retire_fence);
     HWC2::Error SetActiveConfig(hwc2_config_t config);
     HWC2::Error SetClientTarget(buffer_handle_t target, int32_t acquire_fence,
--

2.17.0

Thanks for working on this! Fixup for the nits above:

https://gitlab.freedesktop.org/stschake/drm-hwcomposer/commit/3aa0eb88