wayland: Only init EGLStream controller if we didn't end up with gbm

When we use gbm together with the NVIDIA driver, we want the EGL/Vulkan
clients to do the same, instead of using the EGLStream paths. To achieve
that, make sure to only initialize the EGLStream controller when we
didn't end up using gbm as the renderer backend.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2052>

src/backends/native/meta-renderer-native.c

@@ -239,6 +239,17 @@ meta_renderer_native_has_pending_mode_set (MetaRendererNative *renderer_native)
   return renderer_native->pending_mode_set;
 }
 
+MetaRendererNativeMode
+meta_renderer_native_get_mode (MetaRendererNative *renderer_native)
+{
+  MetaGpuKms *primary_gpu = renderer_native->primary_gpu_kms;
+  MetaRendererNativeGpuData *primary_gpu_data;
+
+  primary_gpu_data = meta_renderer_native_get_gpu_data (renderer_native,
+                                                        primary_gpu);
+  return primary_gpu_data->mode;
+}
+
 static void
 meta_renderer_native_disconnect (CoglRenderer *cogl_renderer)
 {

src/backends/native/meta-renderer-native.h

@@ -68,4 +68,6 @@ void meta_renderer_native_reset_modes (MetaRendererNative *renderer_native);
 
 gboolean meta_renderer_native_use_modifiers (MetaRendererNative *renderer_native);
 
+MetaRendererNativeMode meta_renderer_native_get_mode (MetaRendererNative *renderer_native);
+
 #endif /* META_RENDERER_NATIVE_H */

src/wayland/meta-wayland.c

@@ -51,6 +51,10 @@
 #include "wayland/meta-xwayland-private.h"
 #include "wayland/meta-xwayland.h"
 
+#ifdef HAVE_NATIVE_BACKEND
+#include "backends/native/meta-renderer-native.h"
+#endif
+
 static char *_display_name_override;
 
 G_DEFINE_TYPE (MetaWaylandCompositor, meta_wayland_compositor, G_TYPE_OBJECT)
@@ -573,8 +577,25 @@ meta_wayland_compositor_new (MetaContext *context)
                                   compositor);
 
 #ifdef HAVE_WAYLAND_EGLSTREAM
-  meta_wayland_eglstream_controller_init (compositor);
+    {
-#endif
+      gboolean should_enable_eglstream_controller = TRUE;
+#if defined(HAVE_EGL_DEVICE) && defined(HAVE_NATIVE_BACKEND)
+      MetaRenderer *renderer = meta_backend_get_renderer (backend);
+
+      if (META_IS_RENDERER_NATIVE (renderer))
+        {
+          MetaRendererNative *renderer_native = META_RENDERER_NATIVE (renderer);
+
+          if (meta_renderer_native_get_mode (renderer_native) ==
+              META_RENDERER_NATIVE_MODE_GBM)
+            should_enable_eglstream_controller = FALSE;
+        }
+#endif /* defined(HAVE_EGL_DEVICE) && defined(HAVE_NATIVE_BACKEND) */
+
+      if (should_enable_eglstream_controller)
+        meta_wayland_eglstream_controller_init (compositor);
+    }
+#endif /* HAVE_WAYLAND_EGLSTREAM */
 
   x11_display_policy =
     meta_context_get_x11_display_policy (compositor->context);