[mutter/gnome-41] renderer/native: Try the gbm renderer before the EGLDevice renderer

[Jonas Ådahl <jadahl src gnome org>]

commit 79c9c24fd3df8c1d25526ca15288b7266406b26f
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Oct 11 10:39:43 2021 +0200

    renderer/native: Try the gbm renderer before the EGLDevice renderer
    
    This switches the order of what renderer mode is tried first, so that
    the gbm renderer mode is preferred on an NVIDIA driver where it is
    supported.
    
    We fall back to still try the EGLDevice renderer mode if the created gbm
    renderer is not hardware accelerated.
    
    The last fallback is still to use the gbm renderer, even if it is not
    hardware accelerated, as this is needed when hardware acceleration isn't
    available at all. The original reason for the old order was due to the
    fact that a gbm renderer without hardware acceleration would succeed
    even on NVIDIA driver that didn't support gbm.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2051>
    (cherry picked from commit 8fc1325e8e713dfa05a12c47e6e981e50d3cda61)

 src/backends/native/meta-renderer-native.c | 44 ++++++++++++++++--------------
 1 file changed, 23 insertions(+), 21 deletions(-)
---
diff --git a/src/backends/native/meta-renderer-native.c b/src/backends/native/meta-renderer-native.c
index 40cc0460fc..452503777d 100644
--- a/src/backends/native/meta-renderer-native.c
+++ b/src/backends/native/meta-renderer-native.c
@@ -1876,11 +1876,12 @@ meta_renderer_native_create_renderer_gpu_data (MetaRendererNative  *renderer_nat
   MetaBackend *backend = meta_renderer_get_backend (renderer);
   MetaDevicePool *device_pool =
     meta_backend_native_get_device_pool (META_BACKEND_NATIVE (backend));
-  MetaRendererNativeGpuData *renderer_gpu_data;
+  MetaRendererNativeGpuData *gbm_renderer_gpu_data;
   MetaDeviceFileFlags device_file_flags = META_DEVICE_FILE_FLAG_NONE;
   g_autoptr (MetaDeviceFile) device_file = NULL;
   GError *gbm_error = NULL;
 #ifdef HAVE_EGL_DEVICE
+  MetaRendererNativeGpuData *egl_stream_renderer_gpu_data;
   GError *egl_device_error = NULL;
 #endif
 
@@ -1898,29 +1899,30 @@ meta_renderer_native_create_renderer_gpu_data (MetaRendererNative  *renderer_nat
   if (!device_file)
     return NULL;
 
-#ifdef HAVE_EGL_DEVICE
-  /* Try to initialize the EGLDevice backend first. Whenever we use a
-   * non-NVIDIA GPU, the EGLDevice enumeration function won't find a match, and
-   * we'll fall back to GBM (which will always succeed as it has a software
-   * rendering fallback)
-   */
-  renderer_gpu_data = create_renderer_gpu_data_egl_device (renderer_native,
-                                                           device_file,
-                                                           &egl_device_error);
-  if (renderer_gpu_data)
-    return renderer_gpu_data;
-#endif
-
-  renderer_gpu_data = create_renderer_gpu_data_gbm (renderer_native,
-                                                    device_file,
-                                                    &gbm_error);
-  if (renderer_gpu_data)
+  gbm_renderer_gpu_data = create_renderer_gpu_data_gbm (renderer_native,
+                                                        device_file,
+                                                        &gbm_error);
+  if (gbm_renderer_gpu_data)
     {
+      if (gbm_renderer_gpu_data->secondary.is_hardware_rendering)
+        return gbm_renderer_gpu_data;
+    }
+
 #ifdef HAVE_EGL_DEVICE
-      g_error_free (egl_device_error);
-#endif
-      return renderer_gpu_data;
+  egl_stream_renderer_gpu_data =
+    create_renderer_gpu_data_egl_device (renderer_native,
+                                         device_file,
+                                         &egl_device_error);
+  if (egl_stream_renderer_gpu_data)
+    {
+      g_clear_pointer (&gbm_renderer_gpu_data,
+                       meta_renderer_native_gpu_data_free);
+      return egl_stream_renderer_gpu_data;
     }
+#endif
+
+  if (gbm_renderer_gpu_data)
+    return gbm_renderer_gpu_data;
 
   g_set_error (error, G_IO_ERROR,
                G_IO_ERROR_FAILED,