From 1c25b75571ac51109b9c9203e3df92f598995777 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Mon, 1 Jul 2019 10:49:03 +0200
Subject: [PATCH] kms-impl-device: Fail if we can't enable universal planes

We currently don't handle the lack of DRM_CLIENT_CAP_UNIVERSAL_PLANES
KMS capability. Fail constructing a device that can't handle this up
front, so later made assumptions, such as presence of a primary plane,
are actually valid.

If we want to support lack of said capability, the required planes need
to be emulated by a dummy MetaKmsPlane object.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/665
---
 src/backends/native/meta-kms-device.c      |  4 +++-
 src/backends/native/meta-kms-impl-device.c | 19 ++++++++++++++-----
 src/backends/native/meta-kms-impl-device.h |  7 ++++---
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/src/backends/native/meta-kms-device.c b/src/backends/native/meta-kms-device.c
index 3a626c58c..27dc65e6b 100644
--- a/src/backends/native/meta-kms-device.c
+++ b/src/backends/native/meta-kms-device.c
@@ -156,7 +156,9 @@ create_impl_device_in_impl (MetaKmsImpl  *impl,
   CreateImplDeviceData *data = user_data;
   MetaKmsImplDevice *impl_device;
 
-  impl_device = meta_kms_impl_device_new (data->device, impl, data->fd);
+  impl_device = meta_kms_impl_device_new (data->device, impl, data->fd, error);
+  if (!impl_device)
+    return FALSE;
 
   data->out_impl_device = impl_device;
   data->out_crtcs = meta_kms_impl_device_copy_crtcs (impl_device);
diff --git a/src/backends/native/meta-kms-impl-device.c b/src/backends/native/meta-kms-impl-device.c
index 5f7a43daf..eb5e350ed 100644
--- a/src/backends/native/meta-kms-impl-device.c
+++ b/src/backends/native/meta-kms-impl-device.c
@@ -307,23 +307,32 @@ meta_kms_impl_device_update_states (MetaKmsImplDevice *impl_device)
 }
 
 MetaKmsImplDevice *
-meta_kms_impl_device_new (MetaKmsDevice *device,
-                          MetaKmsImpl   *impl,
-                          int            fd)
+meta_kms_impl_device_new (MetaKmsDevice  *device,
+                          MetaKmsImpl    *impl,
+                          int             fd,
+                          GError        **error)
 {
   MetaKms *kms = meta_kms_impl_get_kms (impl);
   MetaKmsImplDevice *impl_device;
+  int ret;
   drmModeRes *drm_resources;
 
   meta_assert_in_kms_impl (kms);
 
+  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;
+    }
+
   impl_device = g_object_new (META_TYPE_KMS_IMPL_DEVICE, NULL);
   impl_device->device = device;
   impl_device->impl = impl;
   impl_device->fd = fd;
 
-  drmSetClientCap (fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);
-
   drm_resources = drmModeGetResources (fd);
 
   init_crtcs (impl_device, drm_resources);
diff --git a/src/backends/native/meta-kms-impl-device.h b/src/backends/native/meta-kms-impl-device.h
index 6c4b4e540..5390ef575 100644
--- a/src/backends/native/meta-kms-impl-device.h
+++ b/src/backends/native/meta-kms-impl-device.h
@@ -57,8 +57,9 @@ void meta_kms_impl_device_update_states (MetaKmsImplDevice *impl_device);
 
 int meta_kms_impl_device_close (MetaKmsImplDevice *impl_device);
 
-MetaKmsImplDevice * meta_kms_impl_device_new (MetaKmsDevice *device,
-                                              MetaKmsImpl   *kms_impl,
-                                              int            fd);
+MetaKmsImplDevice * meta_kms_impl_device_new (MetaKmsDevice  *device,
+                                              MetaKmsImpl    *kms_impl,
+                                              int             fd,
+                                              GError        **error);
 
 #endif /* META_KMS_IMPL_DEVICE_H */