SF: Add a readonly feature flag for display config error HAL changes

Bug: 374184110
Test: adb shell dumpsys SurfaceFlinger | grep display_config_error_hal
-- Verify that the flag shows up
Flag: com.android.graphics.surfaceflinger.flags.display_config_error_hal

Change-Id: I78af63115914c8ae53dbb04f6d86f601e502ec8f
Signed-off-by: Manasi Navare <navaremanasi@google.com>
diff --git a/services/surfaceflinger/common/FlagManager.cpp b/services/surfaceflinger/common/FlagManager.cpp
index a331491..e35346a 100644
--- a/services/surfaceflinger/common/FlagManager.cpp
+++ b/services/surfaceflinger/common/FlagManager.cpp
@@ -155,6 +155,7 @@
     DUMP_READ_ONLY_FLAG(single_hop_screenshot);
     DUMP_READ_ONLY_FLAG(trace_frame_rate_override);
     DUMP_READ_ONLY_FLAG(true_hdr_screenshots);
+    DUMP_READ_ONLY_FLAG(display_config_error_hal);
 
 #undef DUMP_READ_ONLY_FLAG
 #undef DUMP_SERVER_FLAG
@@ -258,6 +259,7 @@
 FLAG_MANAGER_READ_ONLY_FLAG(force_compile_graphite_renderengine, "");
 FLAG_MANAGER_READ_ONLY_FLAG(single_hop_screenshot, "");
 FLAG_MANAGER_READ_ONLY_FLAG(true_hdr_screenshots, "debug.sf.true_hdr_screenshots");
+FLAG_MANAGER_READ_ONLY_FLAG(display_config_error_hal, "");
 
 /// Trunk stable server flags ///
 FLAG_MANAGER_SERVER_FLAG(refresh_rate_overlay_on_external_display, "")
diff --git a/services/surfaceflinger/common/include/common/FlagManager.h b/services/surfaceflinger/common/include/common/FlagManager.h
index daaf338..5268ffa 100644
--- a/services/surfaceflinger/common/include/common/FlagManager.h
+++ b/services/surfaceflinger/common/include/common/FlagManager.h
@@ -93,6 +93,7 @@
     bool single_hop_screenshot() const;
     bool trace_frame_rate_override() const;
     bool true_hdr_screenshots() const;
+    bool display_config_error_hal() const;
 
 protected:
     // overridden for unit tests
diff --git a/services/surfaceflinger/surfaceflinger_flags_new.aconfig b/services/surfaceflinger/surfaceflinger_flags_new.aconfig
index e40be51..245bc2a 100644
--- a/services/surfaceflinger/surfaceflinger_flags_new.aconfig
+++ b/services/surfaceflinger/surfaceflinger_flags_new.aconfig
@@ -74,6 +74,14 @@
 } # detached_mirror
 
 flag {
+  name: "display_config_error_hal"
+  namespace: "core_graphics"
+  description: "Report HAL display configuration errors like modeset failure or link training failure"
+  bug: "374184110"
+  is_fixed_read_only: true
+} # display_config_error_hal
+
+flag {
   name: "filter_frames_before_trace_starts"
   namespace: "core_graphics"
   description: "Do not trace FrameTimeline events for frames started before the trace started"