[mutter] kms/device: Move universal plane cap check to mode set init

[Marge Bot <marge-bot src gnome org>]

commit 34b0f9c12427598e5ce537271c58c0ef50aa0c38
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Jan 18 18:30:02 2021 +0100

    kms/device: Move universal plane cap check to mode set init
    
    This leaves only the atomic mode setting cap check before creating the
    impl device, aiming to make it possible to create a non-mode-setting
    MetaKmsImplDevice implementation.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>

 src/backends/native/meta-kms-device.c      | 12 ++----------
 src/backends/native/meta-kms-impl-device.c | 10 ++++++++++
 2 files changed, 12 insertions(+), 10 deletions(-)
---
diff --git a/src/backends/native/meta-kms-device.c b/src/backends/native/meta-kms-device.c
index b5b50d602c..9084d248fe 100644
--- a/src/backends/native/meta-kms-device.c
+++ b/src/backends/native/meta-kms-device.c
@@ -281,22 +281,12 @@ meta_create_kms_impl_device (MetaKmsDevice  *device,
 {
   GType impl_device_type;
   gboolean supports_atomic_mode_setting;
-  int ret;
   g_autofree char *driver_name = NULL;
   g_autofree char *driver_description = NULL;
   const char *atomic_kms_enable_env;
 
   meta_assert_in_kms_impl (meta_kms_impl_get_kms (impl));
 
-  ret = drmSetClientCap (fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
-  if (ret != 0)
-    {
-      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ret),
-                   "Failed to activate universal planes: %s",
-                   g_strerror (-ret));
-      return NULL;
-    }
-
   if (!get_driver_info (fd, &driver_name, &driver_description))
     {
       driver_name = g_strdup ("unknown");
@@ -340,6 +330,8 @@ meta_create_kms_impl_device (MetaKmsDevice  *device,
     }
   else
     {
+      int ret;
+
       ret = drmSetClientCap (fd, DRM_CLIENT_CAP_ATOMIC, 1);
       if (ret == 0)
         supports_atomic_mode_setting = TRUE;
diff --git a/src/backends/native/meta-kms-impl-device.c b/src/backends/native/meta-kms-impl-device.c
index 1f72de75b5..f2a000fd1a 100644
--- a/src/backends/native/meta-kms-impl-device.c
+++ b/src/backends/native/meta-kms-impl-device.c
@@ -787,8 +787,18 @@ meta_kms_impl_device_init_mode_setting (MetaKmsImplDevice  *impl_device,
 {
   MetaKmsImplDevicePrivate *priv =
     meta_kms_impl_device_get_instance_private (impl_device);
+  int ret;
   drmModeRes *drm_resources;
 
+  ret = drmSetClientCap (priv->fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
+  if (ret != 0)
+    {
+      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ret),
+                   "Failed to activate universal planes: %s",
+                   g_strerror (-ret));
+      return FALSE;
+    }
+
   drm_resources = drmModeGetResources (priv->fd);
   if (!drm_resources)
     {