[mutter/benzea/ignore-monitor-connector: 2/5] monitor: Add flag whether EDID is sufficient to disambiguate monitors

[Benjamin Berg <bberg src gnome org>]

commit 22e5ad5c67efe1c3d9db0eb63b71682dc261915f
Author: Benjamin Berg <bberg redhat com>
Date:   Fri Dec 20 14:17:46 2019 +0100

    monitor: Add flag whether EDID is sufficient to disambiguate monitors
    
    If the EDID of the attached or stored monitor configurations contain
    proper serial numbers, then we do not need to rely on the connector to
    disambiguate them. Add a boolean to both MetaMonitorManager and
    MetaMonitorsConfigKey to store this information.
    
    https://gitlab.gnome.org/GNOME/mutter/issues/932

 src/backends/meta-monitor-config-manager.c  | 27 +++++++++++++++++++++++++--
 src/backends/meta-monitor-config-manager.h  |  4 ++++
 src/backends/meta-monitor-manager-private.h |  1 +
 src/backends/meta-monitor-manager.c         | 12 ++++++++++++
 src/tests/monitor-store-unit-tests.c        |  3 ++-
 5 files changed, 44 insertions(+), 3 deletions(-)
---
diff --git a/src/backends/meta-monitor-config-manager.c b/src/backends/meta-monitor-config-manager.c
index 9a54ce50f..9d548a634 100644
--- a/src/backends/meta-monitor-config-manager.c
+++ b/src/backends/meta-monitor-config-manager.c
@@ -410,6 +410,27 @@ is_lid_closed (MetaMonitorManager *monitor_manager)
     return meta_backend_is_lid_closed (backend);
 }
 
+gboolean
+meta_config_key_edid_sufficient_for_specs (GList *monitor_specs)
+{
+  GList *l;
+
+  /* Assume the list is sorted. So we just need to check if none of the pairs
+   * are equal when only comparing data from EDID. */
+  for (l = monitor_specs; l && l->next; l = l->next)
+    {
+      MetaMonitorSpec *spec = l->data;
+      MetaMonitorSpec *spec_next = l->next->data;
+
+      if (meta_monitor_spec_equals (spec, spec_next, TRUE))
+        return FALSE;
+
+      /* XXX: Should we reject e.g. only 0 serial numbers? */
+    }
+
+  return TRUE;
+}
+
 MetaMonitorsConfigKey *
 meta_create_monitors_config_key_for_current_state (MetaMonitorManager *monitor_manager)
 {
@@ -439,7 +460,8 @@ meta_create_monitors_config_key_for_current_state (MetaMonitorManager *monitor_m
 
   config_key = g_new0 (MetaMonitorsConfigKey, 1);
   *config_key = (MetaMonitorsConfigKey) {
-    .monitor_specs = monitor_specs
+    .monitor_specs = monitor_specs,
+    .edid_sufficient = meta_config_key_edid_sufficient_for_specs (monitor_specs)
   };
 
   return config_key;
@@ -1251,7 +1273,8 @@ meta_monitors_config_key_new (GList *logical_monitor_configs,
 
   config_key = g_new0 (MetaMonitorsConfigKey, 1);
   *config_key = (MetaMonitorsConfigKey) {
-    .monitor_specs = monitor_specs
+    .monitor_specs = monitor_specs,
+    .edid_sufficient = meta_config_key_edid_sufficient_for_specs (monitor_specs)
   };
 
   return config_key;
diff --git a/src/backends/meta-monitor-config-manager.h b/src/backends/meta-monitor-config-manager.h
index 3875e04e9..b453aa18d 100644
--- a/src/backends/meta-monitor-config-manager.h
+++ b/src/backends/meta-monitor-config-manager.h
@@ -49,6 +49,7 @@ typedef struct _MetaLogicalMonitorConfig
 typedef struct _MetaMonitorsConfigKey
 {
   GList *monitor_specs;
+  gboolean edid_sufficient;
 } MetaMonitorsConfigKey;
 
 typedef enum _MetaMonitorsConfigFlag
@@ -159,6 +160,9 @@ META_EXPORT_TEST
 gboolean meta_monitors_config_key_equal (gconstpointer config_key_a,
                                          gconstpointer config_key_b);
 
+META_EXPORT_TEST
+gboolean meta_config_key_edid_sufficient_for_specs (GList *monitor_specs);
+
 META_EXPORT_TEST
 void meta_monitors_config_key_free (MetaMonitorsConfigKey *config_key);
 
diff --git a/src/backends/meta-monitor-manager-private.h b/src/backends/meta-monitor-manager-private.h
index 20bb6b679..897454697 100644
--- a/src/backends/meta-monitor-manager-private.h
+++ b/src/backends/meta-monitor-manager-private.h
@@ -122,6 +122,7 @@ struct _MetaMonitorManager
   int screen_height;
 
   GList *monitors;
+  gboolean edid_sufficient;
 
   GList *logical_monitors;
   MetaLogicalMonitor *primary_logical_monitor;
diff --git a/src/backends/meta-monitor-manager.c b/src/backends/meta-monitor-manager.c
index b773d436f..0f1968133 100644
--- a/src/backends/meta-monitor-manager.c
+++ b/src/backends/meta-monitor-manager.c
@@ -2621,6 +2621,7 @@ rebuild_monitors (MetaMonitorManager *manager)
 {
   GList *gpus;
   GList *l;
+  GList *specs;
 
   if (manager->monitors)
     {
@@ -2659,6 +2660,17 @@ rebuild_monitors (MetaMonitorManager *manager)
             }
         }
     }
+
+  specs = NULL;
+  for (l = manager->monitors; l; l = l->next)
+    {
+      specs = g_list_prepend (specs, meta_monitor_get_spec ((MetaMonitor*) l->data));
+    }
+
+  specs = g_list_sort (specs,
+                       (GCompareFunc) meta_monitor_spec_compare);
+  manager->edid_sufficient = meta_config_key_edid_sufficient_for_specs (specs);
+  g_list_free (specs);
 }
 
 void
diff --git a/src/tests/monitor-store-unit-tests.c b/src/tests/monitor-store-unit-tests.c
index 4a73d89db..77810e2e7 100644
--- a/src/tests/monitor-store-unit-tests.c
+++ b/src/tests/monitor-store-unit-tests.c
@@ -108,7 +108,8 @@ create_config_key_from_expect (MonitorStoreTestConfiguration *expect_config)
 
   config_key = g_new0 (MetaMonitorsConfigKey, 1);
   *config_key = (MetaMonitorsConfigKey) {
-    .monitor_specs = monitor_specs
+    .monitor_specs = monitor_specs,
+    .edid_sufficient = meta_config_key_edid_sufficient_for_specs (monitor_specs)
   };
 
   return config_key;