[mutter] monitor-manager-kms: Don't listen on hotplugs when paused

[Jonas Ådahl <jadahl src gnome org>]

commit db14e6099e437b64e7c691663f7218c69601f9d9
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Mar 10 16:29:11 2017 +0800

    monitor-manager-kms: Don't listen on hotplugs when paused
    
    When mutter is paused (i.e. not the DRM master), stop listening on
    hotplug events. Instead read the current state and set modes when
    resumed.
    
    This avoids a race condition in the drm API which currently only
    manages to properly deal with one application querying the EDID state
    at the same time when there are multiple mutter instances running at
    the same time (e.g. gnome-shell driving gdm at the same time as
    gnome-shell as the session instance).
    
    https://bugzilla.gnome.org/show_bug.cgi?id=779837

 src/backends/native/meta-backend-native.c      |   16 +++++++++++++---
 src/backends/native/meta-monitor-manager-kms.c |   15 +++++++++++++++
 src/backends/native/meta-monitor-manager-kms.h |    4 ++++
 3 files changed, 32 insertions(+), 3 deletions(-)
---
diff --git a/src/backends/native/meta-backend-native.c b/src/backends/native/meta-backend-native.c
index 22312d7..3cd1d11 100644
--- a/src/backends/native/meta-backend-native.c
+++ b/src/backends/native/meta-backend-native.c
@@ -537,21 +537,31 @@ meta_activate_session (void)
 void
 meta_backend_native_pause (MetaBackendNative *native)
 {
+  MetaBackend *backend = META_BACKEND (native);
+  MetaMonitorManager *monitor_manager =
+    meta_backend_get_monitor_manager (backend);
+  MetaMonitorManagerKms *monitor_manager_kms =
+    META_MONITOR_MANAGER_KMS (monitor_manager);
+
   clutter_evdev_release_devices ();
   clutter_egl_freeze_master_clock ();
+
+  meta_monitor_manager_kms_pause (monitor_manager_kms);
 }
 
 void meta_backend_native_resume (MetaBackendNative *native)
 {
   MetaBackend *backend = META_BACKEND (native);
-  MetaRenderer *renderer;
+  MetaMonitorManager *monitor_manager =
+    meta_backend_get_monitor_manager (backend);
+  MetaMonitorManagerKms *monitor_manager_kms =
+    META_MONITOR_MANAGER_KMS (monitor_manager);
   MetaCursorRenderer *cursor_renderer;
   MetaCursorRendererNative *cursor_renderer_native;
   ClutterActor *stage;
   MetaIdleMonitor *idle_monitor;
 
-  renderer = meta_backend_get_renderer (backend);
-  meta_renderer_native_queue_modes_reset (META_RENDERER_NATIVE (renderer));
+  meta_monitor_manager_kms_resume (monitor_manager_kms);
 
   clutter_evdev_reclaim_devices ();
   clutter_egl_thaw_master_clock ();
diff --git a/src/backends/native/meta-monitor-manager-kms.c b/src/backends/native/meta-monitor-manager-kms.c
index 3cedde1..5256b47 100644
--- a/src/backends/native/meta-monitor-manager-kms.c
+++ b/src/backends/native/meta-monitor-manager-kms.c
@@ -1783,6 +1783,21 @@ meta_monitor_manager_kms_disconnect_uevent_handler (MetaMonitorManagerKms *manag
   manager_kms->uevent_handler_id = 0;
 }
 
+void
+meta_monitor_manager_kms_pause (MetaMonitorManagerKms *manager_kms)
+{
+  meta_monitor_manager_kms_disconnect_uevent_handler (manager_kms);
+}
+
+void
+meta_monitor_manager_kms_resume (MetaMonitorManagerKms *manager_kms)
+{
+  MetaMonitorManager *manager = META_MONITOR_MANAGER (manager_kms);
+
+  meta_monitor_manager_kms_connect_uevent_handler (manager_kms);
+  handle_hotplug_event (manager);
+}
+
 static void
 meta_monitor_manager_kms_init (MetaMonitorManagerKms *manager_kms)
 {
diff --git a/src/backends/native/meta-monitor-manager-kms.h b/src/backends/native/meta-monitor-manager-kms.h
index d4978b8..c641f28 100644
--- a/src/backends/native/meta-monitor-manager-kms.h
+++ b/src/backends/native/meta-monitor-manager-kms.h
@@ -58,4 +58,8 @@ gboolean meta_monitor_manager_kms_flip_crtc (MetaMonitorManagerKms *manager_kms,
 
 void meta_monitor_manager_kms_wait_for_flip (MetaMonitorManagerKms *manager_kms);
 
+void meta_monitor_manager_kms_pause (MetaMonitorManagerKms *manager_kms);
+
+void meta_monitor_manager_kms_resume (MetaMonitorManagerKms *manager_kms);
+
 #endif /* META_MONITOR_MANAGER_KMS_H */