From 425710866438a62843b96272a6cbc6c22174f10c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Mon, 11 Oct 2021 10:39:43 +0200
Subject: [PATCH 2/5] 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 f92f648e5..c851619a1 100644
--- a/src/backends/native/meta-renderer-native.c
+++ b/src/backends/native/meta-renderer-native.c
@@ -1754,38 +1754,40 @@ meta_renderer_native_create_renderer_gpu_data (MetaRendererNative  *renderer_nat
                                                MetaGpuKms          *gpu_kms,
                                                GError             **error)
 {
-  MetaRendererNativeGpuData *renderer_gpu_data;
+  MetaRendererNativeGpuData *gbm_renderer_gpu_data;
   GError *gbm_error = NULL;
 #ifdef HAVE_EGL_DEVICE
+  MetaRendererNativeGpuData *egl_stream_renderer_gpu_data;
   GError *egl_device_error = NULL;
 #endif
 
   if (!gpu_kms)
     return create_renderer_gpu_data_surfaceless (renderer_native, error);
 
-#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,
-                                                           gpu_kms,
-                                                           &egl_device_error);
-  if (renderer_gpu_data)
-    return renderer_gpu_data;
-#endif
-
-  renderer_gpu_data = create_renderer_gpu_data_gbm (renderer_native,
-                                                    gpu_kms,
-                                                    &gbm_error);
-  if (renderer_gpu_data)
+  gbm_renderer_gpu_data = create_renderer_gpu_data_gbm (renderer_native,
+                                                        gpu_kms,
+                                                        &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,
+                                         gpu_kms,
+                                         &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,
-- 
2.35.1