sdm: Merge release fence after set power mode

On SetPowerMode() with retain pipes, DRM driver triggers the kick off
that enables MDP to read the previously queued buffer, Since the fence
created during SetPowerMode() is not merged with the previously queued
buffer, it may result in tearing. Hence get the release fence from
driver on SetPowerMode and propagate it to hwcomposer to merge it with
the previous release fence of all layer buffers to avoid tearing.

Change-Id: I81c078a1b05dd3fb34f10b9b70e25cfbcfabd117
CRs-Fixed: 2184515

19 files changed, 119 insertions, 70 deletions

diff --git a/sdm/libs/core/display_base.cpp b/sdm/libs/core/display_base.cpp
index 383bdba7..b1617b9c 100644
--- a/sdm/libs/core/display_base.cpp
+++ b/sdm/libs/core/display_base.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2014 - 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2014 - 2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
@@ -430,7 +430,7 @@ DisplayState DisplayBase::GetLastPowerMode() {
   return last_power_mode_;
 }
 
-DisplayError DisplayBase::SetDisplayState(DisplayState state) {
+DisplayError DisplayBase::SetDisplayState(DisplayState state, int *release_fence) {
   lock_guard<recursive_mutex> obj(recursive_mutex_);
   DisplayError error = kErrorNone;
   bool active = false;
@@ -452,7 +452,7 @@ DisplayError DisplayBase::SetDisplayState(DisplayState state) {
     break;
 
   case kStateOn:
-    error = hw_intf_->PowerOn();
+    error = hw_intf_->PowerOn(release_fence);
     if (error != kErrorNone) {
       return error;
     }
@@ -468,13 +468,13 @@ DisplayError DisplayBase::SetDisplayState(DisplayState state) {
     break;
 
   case kStateDoze:
-    error = hw_intf_->Doze();
+    error = hw_intf_->Doze(release_fence);
     active = true;
     last_power_mode_ = kStateDoze;
     break;
 
   case kStateDozeSuspend:
-    error = hw_intf_->DozeSuspend();
+    error = hw_intf_->DozeSuspend(release_fence);
     if (display_type_ != kPrimary) {
       active = true;
     }
diff --git a/sdm/libs/core/display_base.h b/sdm/libs/core/display_base.h
index 014ea112..bd597c9c 100644
--- a/sdm/libs/core/display_base.h
+++ b/sdm/libs/core/display_base.h
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2014-2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
@@ -62,7 +62,7 @@ class DisplayBase : public DisplayInterface {
   virtual DisplayError GetConfig(DisplayConfigFixedInfo *variable_info);
   virtual DisplayError GetActiveConfig(uint32_t *index);
   virtual DisplayError GetVSyncState(bool *enabled);
-  virtual DisplayError SetDisplayState(DisplayState state);
+  virtual DisplayError SetDisplayState(DisplayState state, int *release_fence);
   virtual DisplayError SetActiveConfig(uint32_t index);
   virtual DisplayError SetActiveConfig(DisplayConfigVariableInfo *variable_info) {
     return kErrorNotSupported;
diff --git a/sdm/libs/core/display_primary.cpp b/sdm/libs/core/display_primary.cpp
index 8466f8bf..d9fef336 100644
--- a/sdm/libs/core/display_primary.cpp
+++ b/sdm/libs/core/display_primary.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2014 - 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2014 - 2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
@@ -166,10 +166,10 @@ DisplayError DisplayPrimary::Commit(LayerStack *layer_stack) {
   return error;
 }
 
-DisplayError DisplayPrimary::SetDisplayState(DisplayState state) {
+DisplayError DisplayPrimary::SetDisplayState(DisplayState state, int *release_fence) {
   lock_guard<recursive_mutex> obj(recursive_mutex_);
   DisplayError error = kErrorNone;
-  error = DisplayBase::SetDisplayState(state);
+  error = DisplayBase::SetDisplayState(state, release_fence);
   if (error != kErrorNone) {
     return error;
   }
@@ -391,19 +391,26 @@ bool DisplayPrimary::NeedsAVREnable() {
 
 void DisplayPrimary::ResetPanel() {
   DisplayError status = kErrorNone;
+  int release_fence = -1;
 
   DLOGI("Powering off primary");
-  status = SetDisplayState(kStateOff);
+  status = SetDisplayState(kStateOff, &release_fence);
   if (status != kErrorNone) {
     DLOGE("power-off on primary failed with error = %d", status);
   }
+  if (release_fence >= 0) {
+    ::close(release_fence);
+  }
 
   DLOGI("Restoring power mode on primary");
   DisplayState mode = GetLastPowerMode();
-  status = SetDisplayState(mode);
+  status = SetDisplayState(mode, &release_fence);
   if (status != kErrorNone) {
     DLOGE("Setting power mode = %d on primary failed with error = %d", mode, status);
   }
+  if (release_fence >= 0) {
+    ::close(release_fence);
+  }
 
   DLOGI("Enabling HWVsync");
   status = SetVSyncState(true);
diff --git a/sdm/libs/core/display_primary.h b/sdm/libs/core/display_primary.h
index a4dd4b84..e14c6d77 100644
--- a/sdm/libs/core/display_primary.h
+++ b/sdm/libs/core/display_primary.h
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2014 - 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2014 - 2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
@@ -44,7 +44,7 @@ class DisplayPrimary : public DisplayBase, HWEventHandler {
   virtual DisplayError Commit(LayerStack *layer_stack);
   virtual DisplayError ControlPartialUpdate(bool enable, uint32_t *pending);
   virtual DisplayError DisablePartialUpdateOneFrame();
-  virtual DisplayError SetDisplayState(DisplayState state);
+  virtual DisplayError SetDisplayState(DisplayState state, int *release_fence);
   virtual void SetIdleTimeoutMs(uint32_t active_ms);
   virtual DisplayError SetDisplayMode(uint32_t mode);
   virtual DisplayError GetRefreshRateRange(uint32_t *min_refresh_rate, uint32_t *max_refresh_rate);
diff --git a/sdm/libs/core/drm/hw_device_drm.cpp b/sdm/libs/core/drm/hw_device_drm.cpp
index c734f4cd..c01fa5c3 100644
--- a/sdm/libs/core/drm/hw_device_drm.cpp
+++ b/sdm/libs/core/drm/hw_device_drm.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
@@ -708,7 +708,7 @@ DisplayError HWDeviceDRM::GetConfigIndex(char *mode, uint32_t *index) {
   return kErrorNone;
 }
 
-DisplayError HWDeviceDRM::PowerOn() {
+DisplayError HWDeviceDRM::PowerOn(int *release_fence) {
   DTRACE_SCOPED();
   if (!drm_atomic_intf_) {
     DLOGE("DRM Atomic Interface is null!");
@@ -726,6 +726,7 @@ DisplayError HWDeviceDRM::PowerOn() {
     DLOGE("Failed with error: %d", ret);
     return kErrorHardware;
   }
+  drm_atomic_intf_->Perform(DRMOps::CRTC_GET_RELEASE_FENCE, token_.crtc_id, release_fence);
 
   return kErrorNone;
 }
@@ -748,7 +749,7 @@ DisplayError HWDeviceDRM::PowerOff() {
   return kErrorNone;
 }
 
-DisplayError HWDeviceDRM::Doze() {
+DisplayError HWDeviceDRM::Doze(int *release_fence) {
   DTRACE_SCOPED();
   drm_atomic_intf_->Perform(DRMOps::CRTC_SET_ACTIVE, token_.crtc_id, 1);
   drm_atomic_intf_->Perform(DRMOps::CONNECTOR_SET_POWER_MODE, token_.conn_id, DRMPowerMode::DOZE);
@@ -758,10 +759,12 @@ DisplayError HWDeviceDRM::Doze() {
     return kErrorHardware;
   }
 
+  drm_atomic_intf_->Perform(DRMOps::CRTC_GET_RELEASE_FENCE, token_.crtc_id, release_fence);
+
   return kErrorNone;
 }
 
-DisplayError HWDeviceDRM::DozeSuspend() {
+DisplayError HWDeviceDRM::DozeSuspend(int *release_fence) {
   DTRACE_SCOPED();
   drm_atomic_intf_->Perform(DRMOps::CRTC_SET_ACTIVE, token_.crtc_id, 1);
   drm_atomic_intf_->Perform(DRMOps::CONNECTOR_SET_POWER_MODE, token_.conn_id,
@@ -772,6 +775,8 @@ DisplayError HWDeviceDRM::DozeSuspend() {
     return kErrorHardware;
   }
 
+  drm_atomic_intf_->Perform(DRMOps::CRTC_GET_RELEASE_FENCE, token_.crtc_id, release_fence);
+
   return kErrorNone;
 }
 
diff --git a/sdm/libs/core/drm/hw_device_drm.h b/sdm/libs/core/drm/hw_device_drm.h
index b08c0e66..3ecc9a08 100644
--- a/sdm/libs/core/drm/hw_device_drm.h
+++ b/sdm/libs/core/drm/hw_device_drm.h
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
@@ -67,10 +67,10 @@ class HWDeviceDRM : public HWInterface {
   virtual DisplayError SetDisplayAttributes(uint32_t index);
   virtual DisplayError SetDisplayAttributes(const HWDisplayAttributes &display_attributes);
   virtual DisplayError GetConfigIndex(char *mode, uint32_t *index);
-  virtual DisplayError PowerOn();
+  virtual DisplayError PowerOn(int *release_fence);
   virtual DisplayError PowerOff();
-  virtual DisplayError Doze();
-  virtual DisplayError DozeSuspend();
+  virtual DisplayError Doze(int *release_fence);
+  virtual DisplayError DozeSuspend(int *release_fence);
   virtual DisplayError Standby();
   virtual DisplayError Validate(HWLayers *hw_layers);
   virtual DisplayError Commit(HWLayers *hw_layers);
diff --git a/sdm/libs/core/drm/hw_tv_drm.cpp b/sdm/libs/core/drm/hw_tv_drm.cpp
index f1d0d80b..a43ac2cc 100644
--- a/sdm/libs/core/drm/hw_tv_drm.cpp
+++ b/sdm/libs/core/drm/hw_tv_drm.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
@@ -164,11 +164,11 @@ DisplayError HWTVDRM::PowerOff() {
   return kErrorNone;
 }
 
-DisplayError HWTVDRM::Doze() {
+DisplayError HWTVDRM::Doze(int *release_fence) {
   return kErrorNone;
 }
 
-DisplayError HWTVDRM::DozeSuspend() {
+DisplayError HWTVDRM::DozeSuspend(int *release_fence) {
   return kErrorNone;
 }
 
diff --git a/sdm/libs/core/drm/hw_tv_drm.h b/sdm/libs/core/drm/hw_tv_drm.h
index 5661bc27..a87f33d9 100644
--- a/sdm/libs/core/drm/hw_tv_drm.h
+++ b/sdm/libs/core/drm/hw_tv_drm.h
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
@@ -43,8 +43,8 @@ class HWTVDRM : public HWDeviceDRM {
   virtual DisplayError SetDisplayAttributes(uint32_t index);
   virtual DisplayError GetConfigIndex(char *mode, uint32_t *index);
   virtual DisplayError PowerOff();
-  virtual DisplayError Doze();
-  virtual DisplayError DozeSuspend();
+  virtual DisplayError Doze(int *release_fence);
+  virtual DisplayError DozeSuspend(int *release_fence);
   virtual DisplayError Standby();
   virtual DisplayError Commit(HWLayers *hw_layers);
   virtual void PopulateHWPanelInfo();
diff --git a/sdm/libs/core/fb/hw_device.cpp b/sdm/libs/core/fb/hw_device.cpp
index 2c529ae0..1f733a04 100644
--- a/sdm/libs/core/fb/hw_device.cpp
+++ b/sdm/libs/core/fb/hw_device.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2014 - 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2014 - 2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
@@ -155,7 +155,7 @@ DisplayError HWDevice::GetConfigIndex(char *mode, uint32_t *index) {
   return kErrorNone;
 }
 
-DisplayError HWDevice::PowerOn() {
+DisplayError HWDevice::PowerOn(int *release_fence) {
   DTRACE_SCOPED();
 
   if (Sys::ioctl_(device_fd_, FBIOBLANK, FB_BLANK_UNBLANK) < 0) {
@@ -174,11 +174,11 @@ DisplayError HWDevice::PowerOff() {
   return kErrorNone;
 }
 
-DisplayError HWDevice::Doze() {
+DisplayError HWDevice::Doze(int *release_fence) {
   return kErrorNone;
 }
 
-DisplayError HWDevice::DozeSuspend() {
+DisplayError HWDevice::DozeSuspend(int *release_fence) {
   return kErrorNone;
 }
 
diff --git a/sdm/libs/core/fb/hw_device.h b/sdm/libs/core/fb/hw_device.h
index f32c5bda..353cce5b 100644
--- a/sdm/libs/core/fb/hw_device.h
+++ b/sdm/libs/core/fb/hw_device.h
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2014 - 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2014 - 2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
@@ -70,10 +70,10 @@ class HWDevice : public HWInterface {
   virtual DisplayError SetDisplayAttributes(uint32_t index);
   virtual DisplayError SetDisplayAttributes(const HWDisplayAttributes &display_attributes);
   virtual DisplayError GetConfigIndex(char *mode, uint32_t *index);
-  virtual DisplayError PowerOn();
+  virtual DisplayError PowerOn(int *release_fence);
   virtual DisplayError PowerOff();
-  virtual DisplayError Doze();
-  virtual DisplayError DozeSuspend();
+  virtual DisplayError Doze(int *release_fence);
+  virtual DisplayError DozeSuspend(int *release_fence);
   virtual DisplayError Standby();
   virtual DisplayError Validate(HWLayers *hw_layers);
   virtual DisplayError Commit(HWLayers *hw_layers);
diff --git a/sdm/libs/core/fb/hw_primary.cpp b/sdm/libs/core/fb/hw_primary.cpp
index 5ee81219..3f3c28e2 100644
--- a/sdm/libs/core/fb/hw_primary.cpp
+++ b/sdm/libs/core/fb/hw_primary.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2015 - 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2015 - 2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
@@ -344,7 +344,7 @@ DisplayError HWPrimary::PowerOff() {
   return kErrorNone;
 }
 
-DisplayError HWPrimary::Doze() {
+DisplayError HWPrimary::Doze(int *release_fence) {
   if (Sys::ioctl_(device_fd_, FBIOBLANK, FB_BLANK_NORMAL) < 0) {
     IOCTL_LOGE(FB_BLANK_NORMAL, device_type_);
     return kErrorHardware;
@@ -353,7 +353,7 @@ DisplayError HWPrimary::Doze() {
   return kErrorNone;
 }
 
-DisplayError HWPrimary::DozeSuspend() {
+DisplayError HWPrimary::DozeSuspend(int *release_fence) {
   if (Sys::ioctl_(device_fd_, FBIOBLANK, FB_BLANK_VSYNC_SUSPEND) < 0) {
     IOCTL_LOGE(FB_BLANK_VSYNC_SUSPEND, device_type_);
     return kErrorHardware;
diff --git a/sdm/libs/core/fb/hw_primary.h b/sdm/libs/core/fb/hw_primary.h
index 69b54452..c6ca5a98 100644
--- a/sdm/libs/core/fb/hw_primary.h
+++ b/sdm/libs/core/fb/hw_primary.h
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
+* Copyright (c) 2015-2016, 2018 The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
@@ -46,8 +46,8 @@ class HWPrimary : public HWDevice {
   virtual DisplayError SetDisplayAttributes(uint32_t index);
   virtual DisplayError GetConfigIndex(char *mode, uint32_t *index);
   virtual DisplayError PowerOff();
-  virtual DisplayError Doze();
-  virtual DisplayError DozeSuspend();
+  virtual DisplayError Doze(int *release_fence);
+  virtual DisplayError DozeSuspend(int *release_fence);
   virtual DisplayError Validate(HWLayers *hw_layers);
   virtual DisplayError Commit(HWLayers *hw_layers);
   virtual void SetIdleTimeoutMs(uint32_t timeout_ms);
diff --git a/sdm/libs/core/hw_interface.h b/sdm/libs/core/hw_interface.h
index 9bb825e8..483a4df4 100644
--- a/sdm/libs/core/hw_interface.h
+++ b/sdm/libs/core/hw_interface.h
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2014 - 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2014 - 2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted
 * provided that the following conditions are met:
@@ -85,10 +85,10 @@ class HWInterface {
   virtual DisplayError SetDisplayAttributes(uint32_t index) = 0;
   virtual DisplayError SetDisplayAttributes(const HWDisplayAttributes &display_attributes) = 0;
   virtual DisplayError GetConfigIndex(char *mode, uint32_t *index) = 0;
-  virtual DisplayError PowerOn() = 0;
+  virtual DisplayError PowerOn(int *release_fence) = 0;
   virtual DisplayError PowerOff() = 0;
-  virtual DisplayError Doze() = 0;
-  virtual DisplayError DozeSuspend() = 0;
+  virtual DisplayError Doze(int *release_fence) = 0;
+  virtual DisplayError DozeSuspend(int *release_fence) = 0;
   virtual DisplayError Standby() = 0;
   virtual DisplayError Validate(HWLayers *hw_layers) = 0;
   virtual DisplayError Commit(HWLayers *hw_layers) = 0;
diff --git a/sdm/libs/hwc2/display_null.cpp b/sdm/libs/hwc2/display_null.cpp
index 16f4da66..7e52911c 100644
--- a/sdm/libs/hwc2/display_null.cpp
+++ b/sdm/libs/hwc2/display_null.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
@@ -50,7 +50,7 @@ DisplayError DisplayNull::GetDisplayState(DisplayState *state) {
   return kErrorNone;
 }
 
-DisplayError DisplayNull::SetDisplayState(DisplayState state) {
+DisplayError DisplayNull::SetDisplayState(DisplayState state, int *release_fence) {
   state_ = state;
   return kErrorNone;
 }
diff --git a/sdm/libs/hwc2/display_null.h b/sdm/libs/hwc2/display_null.h
index f6c0ddaa..bd49a162 100644
--- a/sdm/libs/hwc2/display_null.h
+++ b/sdm/libs/hwc2/display_null.h
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
@@ -44,7 +44,7 @@ class DisplayNull : public DisplayInterface {
   virtual ~DisplayNull() { }
   virtual DisplayError Commit(LayerStack *layer_stack);
   virtual DisplayError GetDisplayState(DisplayState *state);
-  virtual DisplayError SetDisplayState(DisplayState state);
+  virtual DisplayError SetDisplayState(DisplayState state, int *release_fence);
   virtual DisplayError SetFrameBufferConfig(const DisplayConfigVariableInfo &variable_info);
   virtual DisplayError GetFrameBufferConfig(DisplayConfigVariableInfo *variable_info);
   virtual bool IsUnderscanSupported() { return true; }
diff --git a/sdm/libs/hwc2/hwc_display.cpp b/sdm/libs/hwc2/hwc_display.cpp
index 870b8b64..02801944 100644
--- a/sdm/libs/hwc2/hwc_display.cpp
+++ b/sdm/libs/hwc2/hwc_display.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2017, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
  * Not a Contribution.
  *
  * Copyright 2015 The Android Open Source Project
@@ -748,9 +748,10 @@ HWC2::Error HWCDisplay::SetPowerMode(HWC2::PowerMode mode) {
     default:
       return HWC2::Error::BadParameter;
   }
+  int release_fence = -1;
 
   ATRACE_INT("SetPowerMode ", state);
-  DisplayError error = display_intf_->SetDisplayState(state);
+  DisplayError error = display_intf_->SetDisplayState(state, &release_fence);
   validated_ = false;
 
   if (error == kErrorNone) {
@@ -764,6 +765,20 @@ HWC2::Error HWCDisplay::SetPowerMode(HWC2::PowerMode mode) {
     return HWC2::Error::BadParameter;
   }
 
+  if (release_fence >= 0) {
+    for (auto hwc_layer : layer_set_) {
+      auto fence = hwc_layer->PopBackReleaseFence();
+      auto merged_fence = -1;
+      if (fence >= 0) {
+        merged_fence = sync_merge("sync_merge", release_fence, fence);
+        ::close(fence);
+      } else {
+        merged_fence = ::dup(release_fence);
+      }
+      hwc_layer->PushBackReleaseFence(merged_fence);
+    }
+    ::close(release_fence);
+  }
   return HWC2::Error::None;
 }
 
@@ -1135,7 +1150,7 @@ HWC2::Error HWCDisplay::GetReleaseFences(uint32_t *out_num_elements, hwc2_layer_
     for (uint32_t i = 0; i < *out_num_elements; i++, it++) {
       auto hwc_layer = *it;
       out_layers[i] = hwc_layer->GetId();
-      out_fences[i] = hwc_layer->PopReleaseFence();
+      out_fences[i] = hwc_layer->PopFrontReleaseFence();
     }
   } else {
     *out_num_elements = UINT32(layer_set_.size());
@@ -1306,15 +1321,15 @@ HWC2::Error HWCDisplay::PostCommitLayerStack(int32_t *out_retire_fence) {
       if (swap_interval_zero_ || layer->flags.single_buffer) {
         close(layer_buffer->release_fence_fd);
       } else if (layer->composition != kCompositionGPU) {
-        hwc_layer->PushReleaseFence(layer_buffer->release_fence_fd);
+        hwc_layer->PushBackReleaseFence(layer_buffer->release_fence_fd);
       } else {
-        hwc_layer->PushReleaseFence(-1);
+        hwc_layer->PushBackReleaseFence(-1);
       }
     } else {
       // In case of flush, we don't return an error to f/w, so it will get a release fence out of
       // the hwc_layer's release fence queue. We should push a -1 to preserve release fence
       // circulation semantics.
-      hwc_layer->PushReleaseFence(-1);
+      hwc_layer->PushBackReleaseFence(-1);
     }
 
     layer_buffer->release_fence_fd = -1;
diff --git a/sdm/libs/hwc2/hwc_display_external.cpp b/sdm/libs/hwc2/hwc_display_external.cpp
index 2bc2d189..675484b8 100644
--- a/sdm/libs/hwc2/hwc_display_external.cpp
+++ b/sdm/libs/hwc2/hwc_display_external.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2014-2017, The Linux Foundation. All rights reserved.
+* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
@@ -230,9 +230,12 @@ int HWCDisplayExternal::SetState(bool connected) {
         DLOGW("Set frame buffer config failed. Error = %d", error);
         return -1;
       }
-
+      int release_fence = -1;
       display_null_.GetDisplayState(&state);
-      display_intf_->SetDisplayState(state);
+      display_intf_->SetDisplayState(state, &release_fence);
+      if (release_fence >= 0) {
+        ::close(release_fence);
+      }
       validated_ = false;
 
       SetVsyncEnabled(HWC2::Vsync::Enable);
@@ -244,10 +247,14 @@ int HWCDisplayExternal::SetState(bool connected) {
     }
   } else {
     if (!display_null_.IsActive()) {
+      int release_fence = -1;
       // Preserve required attributes of HDMI display that surfaceflinger sees.
       // Restore HDMI attributes when display is reconnected.
       display_intf_->GetDisplayState(&state);
-      display_null_.SetDisplayState(state);
+      display_null_.SetDisplayState(state, &release_fence);
+      if (release_fence >= 0) {
+        ::close(release_fence);
+      }
 
       error = display_intf_->GetFrameBufferConfig(&fb_config);
       if (error != kErrorNone) {
diff --git a/sdm/libs/hwc2/hwc_layers.cpp b/sdm/libs/hwc2/hwc_layers.cpp
index d611352e..1193ec46 100644
--- a/sdm/libs/hwc2/hwc_layers.cpp
+++ b/sdm/libs/hwc2/hwc_layers.cpp
@@ -174,14 +174,14 @@ HWCLayer::HWCLayer(hwc2_display_t display_id, HWCBufferAllocator *buf_allocator)
   layer_ = new Layer();
   // Fences are deferred, so the first time this layer is presented, return -1
   // TODO(user): Verify that fences are properly obtained on suspend/resume
-  release_fences_.push(-1);
+  release_fences_.push_back(-1);
 }
 
 HWCLayer::~HWCLayer() {
   // Close any fences left for this layer
   while (!release_fences_.empty()) {
     ::close(release_fences_.front());
-    release_fences_.pop();
+    release_fences_.pop_front();
   }
   if (layer_) {
     if (layer_->input_buffer.acquire_fence_fd >= 0) {
@@ -892,14 +892,28 @@ void HWCLayer::SetComposition(const LayerComposition &sdm_composition) {
 
   return;
 }
-void HWCLayer::PushReleaseFence(int32_t fence) {
-  release_fences_.push(fence);
+
+void HWCLayer::PushBackReleaseFence(int32_t fence) {
+  release_fences_.push_back(fence);
 }
-int32_t HWCLayer::PopReleaseFence(void) {
+
+int32_t HWCLayer::PopBackReleaseFence() {
   if (release_fences_.empty())
     return -1;
+
+  auto fence = release_fences_.back();
+  release_fences_.pop_back();
+
+  return fence;
+}
+
+int32_t HWCLayer::PopFrontReleaseFence() {
+  if (release_fences_.empty())
+    return -1;
+
   auto fence = release_fences_.front();
-  release_fences_.pop();
+  release_fences_.pop_front();
+
   return fence;
 }
 
diff --git a/sdm/libs/hwc2/hwc_layers.h b/sdm/libs/hwc2/hwc_layers.h
index ed03c50c..a7d7f011 100644
--- a/sdm/libs/hwc2/hwc_layers.h
+++ b/sdm/libs/hwc2/hwc_layers.h
@@ -32,7 +32,7 @@
 #undef HWC2_INCLUDE_STRINGIFICATION
 #undef HWC2_USE_CPP11
 #include <map>
-#include <queue>
+#include <deque>
 #include <set>
 #include "core/buffer_allocator.h"
 #include "hwc_buffer_allocator.h"
@@ -88,8 +88,9 @@ class HWCLayer {
   int32_t GetLayerDataspace() { return dataspace_; }
   uint32_t GetGeometryChanges() { return geometry_changes_; }
   void ResetGeometryChanges() { geometry_changes_ = GeometryChanges::kNone; }
-  void PushReleaseFence(int32_t fence);
-  int32_t PopReleaseFence(void);
+  void PushBackReleaseFence(int32_t fence);
+  int32_t PopBackReleaseFence(void);
+  int32_t PopFrontReleaseFence(void);
   bool ValidateAndSetCSC();
   bool SupportLocalConversion(ColorPrimaries working_primaries);
   void ResetValidation() { needs_validate_ = false; }
@@ -104,7 +105,7 @@ class HWCLayer {
   const hwc2_layer_t id_;
   const hwc2_display_t display_id_;
   static std::atomic<hwc2_layer_t> next_id_;
-  std::queue<int32_t> release_fences_;
+  std::deque<int32_t> release_fences_;
   HWCBufferAllocator *buffer_allocator_ = NULL;
   int32_t dataspace_ =  HAL_DATASPACE_UNKNOWN;
   LayerTransform layer_transform_ = {};