ui: Add more logging around Take/RelinquishDisplayControl

Take and RelinquishDisplayControls are called when ash takes or
releases DRM master for all DRM devices. When these calls fail, there's
often not a lot of information on why they failed, which makes
debugging/root causing difficult. This CL adds more verbose error
logging around failure cases to make the cause of failure more apparent
in logs.

Bug: b:330543865
Test: ozone_unittests && display_unittests
Change-Id: Iead5110d54099546e09247981446ed2b1ac34a3b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5813185
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Commit-Queue: Su Hong Koo <sukoo@chromium.org>
Reviewed-by: Gil Dekel <gildekel@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1347527}

ui/display/manager/display_configurator.cc

@@ -658,11 +658,16 @@ void DisplayConfigurator::SetConfigureDisplays(bool configure_displays) {
 
 void DisplayConfigurator::TakeControl(DisplayControlCallback callback) {
   if (display_control_changing_) {
+    LOG(ERROR) << __func__
+               << " failed. There is another RelinquishControl() or "
+                  "TakeControl() call in progress.";
     std::move(callback).Run(false);
     return;
   }
 
   if (!display_externally_controlled_) {
+    LOG(ERROR) << __func__
+               << " failed. Displays are not controlled externally.";
     std::move(callback).Run(true);
     return;
   }
@@ -692,17 +697,24 @@ void DisplayConfigurator::OnDisplayControlTaken(DisplayControlCallback callback,
 
 void DisplayConfigurator::RelinquishControl(DisplayControlCallback callback) {
   if (display_control_changing_) {
+    LOG(ERROR) << __func__
+               << " failed. There is another RelinquishControl() or "
+                  "TakeControl() call in progress.";
     std::move(callback).Run(false);
     return;
   }
 
   if (display_externally_controlled_) {
+    LOG(ERROR) << __func__
+               << " failed. Displays are already controlled externally.";
     std::move(callback).Run(true);
     return;
   }
 
   // For simplicity, just fail if in the middle of a display configuration.
   if (configuration_task_) {
+    LOG(ERROR) << __func__
+               << " failed. There is a display configuration in progress.";
     std::move(callback).Run(false);
     return;
   }
@@ -735,6 +747,9 @@ void DisplayConfigurator::SendRelinquishDisplayControl(
         base::BindOnce(&DisplayConfigurator::OnDisplayControlRelinquished,
                        weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
   } else {
+    LOG(ERROR) << __func__
+               << "failed. Failed to turn off all displays before "
+                  "relinquishing control.";
     display_control_changing_ = false;
     std::move(callback).Run(false);
   }

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

@@ -363,8 +363,15 @@ MovableDisplaySnapshots DrmGpuDisplayManager::GetDisplays() {
 bool DrmGpuDisplayManager::TakeDisplayControl() {
   const DrmDeviceVector& devices = drm_device_manager_->GetDrmDevices();
   bool status = true;
-  for (const auto& drm : devices)
-    status &= drm->SetMaster();
+  for (const auto& drm : devices) {
+    const bool set_master_status = drm->SetMaster();
+    if (!set_master_status) {
+      LOG(ERROR) << __func__ << "Drm set master failed for: "  // nocheck
+                 << drm->device_path().value();
+    }
+
+    status &= set_master_status;
+  }
 
   // Roll-back any successful operation.
   if (!status) {
@@ -377,8 +384,12 @@ bool DrmGpuDisplayManager::TakeDisplayControl() {
 
 void DrmGpuDisplayManager::RelinquishDisplayControl() {
   const DrmDeviceVector& devices = drm_device_manager_->GetDrmDevices();
-  for (const auto& drm : devices)
-    drm->DropMaster();
+  for (const auto& drm : devices) {
+    if (!drm->DropMaster()) {
+      LOG(ERROR) << __func__ << "Drm drop master failed for: "  // nocheck
+                 << drm->device_path().value();
+    }
+  }
 }
 
 bool DrmGpuDisplayManager::ShouldDisplayEventTriggerConfiguration(

ui/ozone/platform/drm/host/host_drm_device.cc

@@ -146,8 +146,10 @@ void HostDrmDevice::GpuConfigureNativeDisplays(
 
 bool HostDrmDevice::GpuTakeDisplayControl() {
   DCHECK_CALLED_ON_VALID_THREAD(on_ui_thread_);
-  if (!IsConnected())
+  if (!IsConnected()) {
+    LOG(WARNING) << __func__ << " GPU service not connected.";
     return false;
+  }
   auto callback =
       base::BindOnce(&HostDrmDevice::GpuTakeDisplayControlCallback, this);
 
@@ -158,8 +160,10 @@ bool HostDrmDevice::GpuTakeDisplayControl() {
 
 bool HostDrmDevice::GpuRelinquishDisplayControl() {
   DCHECK_CALLED_ON_VALID_THREAD(on_ui_thread_);
-  if (!IsConnected())
+  if (!IsConnected()) {
+    LOG(WARNING) << __func__ << " GPU service not connected.";
     return false;
+  }
   auto callback =
       base::BindOnce(&HostDrmDevice::GpuRelinquishDisplayControlCallback, this);