From 12d12eb2785882a2e180ebea8c97afe347c9f4b2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michel=20D=C3=A4nzer?= <mdaenzer@redhat.com>
Date: Thu, 27 Jun 2024 18:02:33 +0200
Subject: [PATCH] drm-timeline: Add meta_drm_timeline_create_syncobj

Creates a kernel syncobj and returns a file descriptor representing it.

v2:
* Call drmSyncobjDestroy also after drmSyncobjHandleToFD returns 0, or
  we leak the original syncobj reference. (Sebastian Wick)
* Add errno based error messages.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3876>
---
 src/common/meta-drm-timeline.c | 31 +++++++++++++++++++++++++++++++
 src/common/meta-drm-timeline.h |  3 +++
 2 files changed, 34 insertions(+)

diff --git a/src/common/meta-drm-timeline.c b/src/common/meta-drm-timeline.c
index c5ec1a2de..9d10318fa 100644
--- a/src/common/meta-drm-timeline.c
+++ b/src/common/meta-drm-timeline.c
@@ -141,6 +141,37 @@ initable_iface_init (GInitableIface *initable_iface)
   initable_iface->init = meta_drm_timeline_initable_init;
 }
 
+int
+meta_drm_timeline_create_syncobj (int      drm_fd,
+                                  GError **error)
+{
+  uint32_t syncobj_handle;
+  int syncobj_fd;
+
+  if (drmSyncobjCreate (drm_fd, 0, &syncobj_handle))
+    {
+      g_set_error (error,
+                   G_IO_ERROR,
+                   G_IO_ERROR_FAILED,
+                   "drmSyncobjCreate failed: %s",
+                   g_strerror (errno));
+      return -1;
+    }
+
+  if (drmSyncobjHandleToFD (drm_fd, syncobj_handle, &syncobj_fd) < 0)
+    {
+      syncobj_fd = -1;
+      g_set_error (error,
+                   G_IO_ERROR,
+                   G_IO_ERROR_FAILED,
+                   "drmSyncobjHandleToFD failed: %s",
+                   g_strerror (errno));
+    }
+
+  drmSyncobjDestroy (drm_fd, syncobj_handle);
+  return syncobj_fd;
+}
+
 MetaDrmTimeline *
 meta_drm_timeline_import_syncobj (int       fd,
                                   int       drm_syncobj,
diff --git a/src/common/meta-drm-timeline.h b/src/common/meta-drm-timeline.h
index 9ad6a6301..11166b450 100644
--- a/src/common/meta-drm-timeline.h
+++ b/src/common/meta-drm-timeline.h
@@ -30,6 +30,9 @@ G_DECLARE_FINAL_TYPE (MetaDrmTimeline, meta_drm_timeline,
 
 typedef struct _MetaDrmTimeline MetaDrmTimeline;
 
+int meta_drm_timeline_create_syncobj (int      fd,
+                                      GError **error);
+
 MetaDrmTimeline * meta_drm_timeline_import_syncobj (int       fd,
                                                     int       drm_syncobj,
                                                     GError  **error);