kms/impl-device: Add and remove connectors on hot plug

Connectors may disappear and appear on hot plugs, e.g. when a docking
station is connected, so when processing a hot plug event, make sure we
remove connectors that are now gone, and add new ones that have appeared
since last time.

Fixes: https://gitlab.gnome.org/GNOME/mutter/issues/728

https://gitlab.gnome.org/GNOME/mutter/merge_requests/743

8 files changed, 105 insertions, 21 deletions

diff --git a/src/backends/native/meta-kms-connector-private.h b/src/backends/native/meta-kms-connector-private.h
index f61e96948..427502a34 100644
--- a/src/backends/native/meta-kms-connector-private.h
+++ b/src/backends/native/meta-kms-connector-private.h
@@ -29,4 +29,7 @@ MetaKmsConnector * meta_kms_connector_new (MetaKmsImplDevice *impl_device,
                                            drmModeConnector  *drm_connector,
                                            drmModeRes        *drm_resources);
 
+gboolean meta_kms_connector_is_same_as (MetaKmsConnector *connector,
+                                        drmModeConnector *drm_connector);
+
 #endif /* META_KMS_CONNECTOR_PRIVATE_H */
diff --git a/src/backends/native/meta-kms-connector.c b/src/backends/native/meta-kms-connector.c
index 8eed11229..1508d4fea 100644
--- a/src/backends/native/meta-kms-connector.c
+++ b/src/backends/native/meta-kms-connector.c
@@ -36,6 +36,7 @@ struct _MetaKmsConnector
 
   uint32_t id;
   MetaConnectorType type;
+  uint32_t type_id;
   char *name;
 
   MetaKmsConnectorState *current_state;
@@ -562,6 +563,15 @@ make_connector_name (drmModeConnector *drm_connector)
                             drm_connector->connector_type_id);
 }
 
+gboolean
+meta_kms_connector_is_same_as (MetaKmsConnector *connector,
+                               drmModeConnector *drm_connector)
+{
+  return (connector->id == drm_connector->connector_id &&
+          connector->type == drm_connector->connector_type &&
+          connector->type_id == drm_connector->connector_type_id);
+}
+
 MetaKmsConnector *
 meta_kms_connector_new (MetaKmsImplDevice *impl_device,
                         drmModeConnector  *drm_connector,
@@ -573,6 +583,7 @@ meta_kms_connector_new (MetaKmsImplDevice *impl_device,
   connector->device = meta_kms_impl_device_get_device (impl_device);
   connector->id = drm_connector->connector_id;
   connector->type = (MetaConnectorType) drm_connector->connector_type;
+  connector->type_id = drm_connector->connector_type_id;
   connector->name = make_connector_name (drm_connector);
 
   find_property_ids (connector, impl_device, drm_connector);
diff --git a/src/backends/native/meta-kms-device-private.h b/src/backends/native/meta-kms-device-private.h
index 0d4f4e341..bcb3a6e74 100644
--- a/src/backends/native/meta-kms-device-private.h
+++ b/src/backends/native/meta-kms-device-private.h
@@ -24,4 +24,7 @@
 
 MetaKmsImplDevice * meta_kms_device_get_impl_device (MetaKmsDevice *device);
 
+void meta_kms_device_update_states_in_impl (MetaKmsDevice            *device,
+                                            MetaKmsUpdateStatesFlags  flags);
+
 #endif /* META_KMS_DEVICE_PRIVATE_H */
diff --git a/src/backends/native/meta-kms-device.c b/src/backends/native/meta-kms-device.c
index 27dc65e6b..be0362ddc 100644
--- a/src/backends/native/meta-kms-device.c
+++ b/src/backends/native/meta-kms-device.c
@@ -108,6 +108,31 @@ meta_kms_device_get_primary_plane_for (MetaKmsDevice *device,
   return NULL;
 }
 
+void
+meta_kms_device_update_states_in_impl (MetaKmsDevice            *device,
+                                       MetaKmsUpdateStatesFlags  flags)
+{
+  MetaKmsImplDevice *impl_device = meta_kms_device_get_impl_device (device);
+
+  meta_assert_in_kms_impl (device->kms);
+
+  meta_kms_impl_device_update_states (impl_device, flags);
+
+  if (flags & META_KMS_UPDATE_STATES_FLAG_HOTPLUG)
+    {
+      meta_assert_is_waiting_for_kms_impl_task (device->kms);
+
+      g_list_free (device->crtcs);
+      device->crtcs = meta_kms_impl_device_copy_crtcs (impl_device);
+
+      g_list_free (device->connectors);
+      device->connectors = meta_kms_impl_device_copy_connectors (impl_device);
+
+      g_list_free (device->planes);
+      device->planes = meta_kms_impl_device_copy_planes (impl_device);
+    }
+}
+
 static gboolean
 dispatch_in_impl (MetaKmsImpl  *impl,
                   gpointer      user_data,
diff --git a/src/backends/native/meta-kms-impl-device.c b/src/backends/native/meta-kms-impl-device.c
index c46d74646..2f7cb7f89 100644
--- a/src/backends/native/meta-kms-impl-device.c
+++ b/src/backends/native/meta-kms-impl-device.c
@@ -196,10 +196,28 @@ init_crtcs (MetaKmsImplDevice *impl_device,
   impl_device->crtcs = g_list_reverse (impl_device->crtcs);
 }
 
+static MetaKmsConnector *
+find_existing_connector (MetaKmsImplDevice *impl_device,
+                         drmModeConnector  *drm_connector)
+{
+  GList *l;
+
+  for (l = impl_device->connectors; l; l = l->next)
+    {
+      MetaKmsConnector *connector = l->data;
+
+      if (meta_kms_connector_is_same_as (connector, drm_connector))
+        return connector;
+    }
+
+  return NULL;
+}
+
 static void
-init_connectors (MetaKmsImplDevice *impl_device,
-                 drmModeRes        *drm_resources)
+update_connectors (MetaKmsImplDevice *impl_device,
+                   drmModeRes        *drm_resources)
 {
+  GList *connectors = NULL;
   unsigned int i;
 
   for (i = 0; i < drm_resources->count_connectors; i++)
@@ -212,14 +230,19 @@ init_connectors (MetaKmsImplDevice *impl_device,
       if (!drm_connector)
         continue;
 
-      connector = meta_kms_connector_new (impl_device, drm_connector,
-                                          drm_resources);
+      connector = find_existing_connector (impl_device, drm_connector);
+      if (connector)
+        connector = g_object_ref (connector);
+      else
+        connector = meta_kms_connector_new (impl_device, drm_connector,
+                                            drm_resources);
       drmModeFreeConnector (drm_connector);
 
-      impl_device->connectors = g_list_prepend (impl_device->connectors,
-                                                connector);
+      connectors = g_list_prepend (connectors, connector);
     }
-  impl_device->connectors = g_list_reverse (impl_device->connectors);
+
+  g_list_free_full (impl_device->connectors, g_object_unref);
+  impl_device->connectors = g_list_reverse (connectors);
 }
 
 static MetaKmsPlaneType
@@ -295,13 +318,18 @@ init_planes (MetaKmsImplDevice *impl_device)
 }
 
 void
-meta_kms_impl_device_update_states (MetaKmsImplDevice *impl_device)
+meta_kms_impl_device_update_states (MetaKmsImplDevice        *impl_device,
+                                    MetaKmsUpdateStatesFlags  flags)
 {
   drmModeRes *drm_resources;
 
   meta_assert_in_kms_impl (meta_kms_impl_get_kms (impl_device->impl));
 
   drm_resources = drmModeGetResources (impl_device->fd);
+
+  if (flags & META_KMS_UPDATE_STATES_FLAG_HOTPLUG)
+    update_connectors (impl_device, drm_resources);
+
   g_list_foreach (impl_device->crtcs, (GFunc) meta_kms_crtc_update_state,
                   NULL);
   g_list_foreach (impl_device->connectors, (GFunc) meta_kms_connector_update_state,
@@ -346,9 +374,10 @@ meta_kms_impl_device_new (MetaKmsDevice  *device,
   impl_device->fd = fd;
 
   init_crtcs (impl_device, drm_resources);
-  init_connectors (impl_device, drm_resources);
   init_planes (impl_device);
 
+  update_connectors (impl_device, drm_resources);
+
   drmModeFreeResources (drm_resources);
 
   impl_device->fd_source =
diff --git a/src/backends/native/meta-kms-impl-device.h b/src/backends/native/meta-kms-impl-device.h
index 5390ef575..1e971af8b 100644
--- a/src/backends/native/meta-kms-impl-device.h
+++ b/src/backends/native/meta-kms-impl-device.h
@@ -53,7 +53,8 @@ int meta_kms_impl_device_get_fd (MetaKmsImplDevice *impl_device);
 
 int meta_kms_impl_device_leak_fd (MetaKmsImplDevice *impl_device);
 
-void meta_kms_impl_device_update_states (MetaKmsImplDevice *impl_device);
+void meta_kms_impl_device_update_states (MetaKmsImplDevice        *impl_device,
+                                         MetaKmsUpdateStatesFlags  flags);
 
 int meta_kms_impl_device_close (MetaKmsImplDevice *impl_device);
 
diff --git a/src/backends/native/meta-kms-types.h b/src/backends/native/meta-kms-types.h
index dd14a7be7..ed4a4cd9d 100644
--- a/src/backends/native/meta-kms-types.h
+++ b/src/backends/native/meta-kms-types.h
@@ -56,4 +56,10 @@ typedef enum _MetaKmsDeviceFlag
   META_KMS_DEVICE_FLAG_PLATFORM_DEVICE = 1 << 1,
 } MetaKmsDeviceFlag;
 
+typedef enum _MetaKmsUpdateStatesFlags
+{
+  META_KMS_UPDATE_STATES_FLAG_NONE = 0,
+  META_KMS_UPDATE_STATES_FLAG_HOTPLUG = 1 << 0,
+} MetaKmsUpdateStatesFlags;
+
 #endif /* META_KMS_IMPL_TYPES_H */
diff --git a/src/backends/native/meta-kms.c b/src/backends/native/meta-kms.c
index 91b260db3..8397f872e 100644
--- a/src/backends/native/meta-kms.c
+++ b/src/backends/native/meta-kms.c
@@ -167,7 +167,8 @@ struct _MetaKms
 G_DEFINE_TYPE (MetaKms, meta_kms, G_TYPE_OBJECT)
 
 static void
-meta_kms_update_states_in_impl (MetaKms *kms);
+meta_kms_update_states_in_impl (MetaKms                  *kms,
+                                MetaKmsUpdateStatesFlags  flags);
 
 MetaKmsUpdate *
 meta_kms_ensure_pending_update (MetaKms *kms)
@@ -195,7 +196,8 @@ meta_kms_update_process_in_impl (MetaKmsImpl  *impl,
   ret = meta_kms_impl_process_update (impl, update, error);
 
   if (meta_kms_update_has_mode_set (update))
-    meta_kms_update_states_in_impl (meta_kms_impl_get_kms (impl));
+    meta_kms_update_states_in_impl (meta_kms_impl_get_kms (impl),
+                                    META_KMS_UPDATE_STATES_FLAG_NONE);
 
   return ret;
 }
@@ -450,7 +452,8 @@ meta_kms_is_waiting_for_impl_task (MetaKms *kms)
 }
 
 static void
-meta_kms_update_states_in_impl (MetaKms *kms)
+meta_kms_update_states_in_impl (MetaKms                  *kms,
+                                MetaKmsUpdateStatesFlags  flags)
 {
   GList *l;
 
@@ -462,9 +465,8 @@ meta_kms_update_states_in_impl (MetaKms *kms)
   for (l = kms->devices; l; l = l->next)
     {
       MetaKmsDevice *device = l->data;
-      MetaKmsImplDevice *impl_device = meta_kms_device_get_impl_device (device);
 
-      meta_kms_impl_device_update_states (impl_device);
+      meta_kms_device_update_states_in_impl (device, flags);
     }
 }
 
@@ -473,20 +475,22 @@ update_states_in_impl (MetaKmsImpl  *impl,
                        gpointer      user_data,
                        GError      **error)
 {
-  MetaKms *kms = user_data;
+  MetaKms *kms = meta_kms_impl_get_kms (impl);;
+  MetaKmsUpdateStatesFlags flags = GPOINTER_TO_UINT (user_data);
 
-  meta_kms_update_states_in_impl (kms);
+  meta_kms_update_states_in_impl (kms, flags);
 
   return TRUE;
 }
 
 static gboolean
-meta_kms_update_states_sync (MetaKms  *kms,
-                             GError  **error)
+meta_kms_update_states_sync (MetaKms                   *kms,
+                             MetaKmsUpdateStatesFlags   flags,
+                             GError                   **error)
 {
   return meta_kms_run_impl_task_sync (kms,
                                       update_states_in_impl,
-                                      kms,
+                                      GUINT_TO_POINTER (flags),
                                       error);
 }
 
@@ -495,7 +499,9 @@ handle_hotplug_event (MetaKms *kms)
 {
   g_autoptr (GError) error = NULL;
 
-  if (!meta_kms_update_states_sync (kms, &error))
+  if (!meta_kms_update_states_sync (kms,
+                                    META_KMS_UPDATE_STATES_FLAG_HOTPLUG,
+                                    &error))
     g_warning ("Updating KMS state failed: %s", error->message);
 }