logind: rework display counting when detecting whether the system is docked

Previously, we'd just count connected displays, and if there was 2 or
more we assumed a "docked" state.

With this change we now:

- Only count external displays, ignore internal ones (which we detect by
  checking the connector name against a whitelist of known external plug
  types)

- We ignore connectors which are explicitly disabled

- We then compare the count with >= 1 rather than >= 2 as before

This new logic has the benefit that systems that disconnect the internal
display when the lid is closed are better supported. Also, explicitly
disabled ports do not confuse the algorithm anymore.

This new algorithm has been suggested here:

http://lists.freedesktop.org/archives/intel-gfx/2015-June/068821.html

This also makes two functions static, that are not used outside of their
.c files.

diff --git a/src/login/logind-button.c b/src/login/logind-button.c
index 8079d0b5aa93231341570bfbb1386becae99edf2..210b889c4f987cd7998b38ac69e0578c77e98603 100644 (file)
--- a/src/login/logind-button.c
+++ b/src/login/logind-button.c
@@ -100,7 +100,7 @@ static void button_lid_switch_handle_action(Manager *manager, bool is_edge) {
         assert(manager);
 
         /* If we are docked, handle the lid switch differently */
-        if (manager_is_docked_or_multiple_displays(manager))
+        if (manager_is_docked_or_external_displays(manager))
                 handle_action = manager->handle_lid_switch_docked;
         else
                 handle_action = manager->handle_lid_switch;

diff --git a/src/login/logind-core.c b/src/login/logind-core.c
index f9e6ddfb3fb53a8054ad0d3c94cc5292a183e23b..a6c01f7d85bcb4dbff6730dc1ce37393ed3dc42f 100644 (file)
--- a/src/login/logind-core.c
+++ b/src/login/logind-core.c
@@ -477,7 +477,7 @@ int manager_spawn_autovt(Manager *m, unsigned int vtnr) {
         return r;
 }
 
-bool manager_is_docked(Manager *m) {
+static bool manager_is_docked(Manager *m) {
         Iterator i;
         Button *b;
 
@@ -488,7 +488,7 @@ bool manager_is_docked(Manager *m) {
         return false;
 }
 
-int manager_count_displays(Manager *m) {
+static int manager_count_external_displays(Manager *m) {
         _cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
         struct udev_list_entry *item = NULL, *first = NULL;
         int r;
@@ -510,7 +510,8 @@ int manager_count_displays(Manager *m) {
         udev_list_entry_foreach(item, first) {
                 _cleanup_udev_device_unref_ struct udev_device *d = NULL;
                 struct udev_device *p;
-                const char *status;
+                const char *status, *enabled, *dash, *nn, *i;
+                bool external = false;
 
                 d = udev_device_new_from_syspath(m->udev, udev_list_entry_get_name(item));
                 if (!d)
@@ -526,6 +527,40 @@ int manager_count_displays(Manager *m) {
                 if (!streq_ptr(udev_device_get_subsystem(p), "drm"))
                         continue;
 
+                nn = udev_device_get_sysname(d);
+                if (!nn)
+                        continue;
+
+                /* Ignore internal displays: the type is encoded in
+                 * the sysfs name, as the second dash seperated item
+                 * (the first is the card name, the last the connector
+                 * number). We implement a whitelist of external
+                 * displays here, rather than a whitelist, to ensure
+                 * we don't block suspends too eagerly. */
+                dash = strchr(nn, '-');
+                if (!dash)
+                        continue;
+
+                dash++;
+                FOREACH_STRING(i, "VGA-", "DVI-I-", "DVI-D-", "DVI-A-"
+                               "Composite-", "SVIDEO-", "Component-",
+                               "DIN-", "DP-", "HDMI-A-", "HDMI-B-", "TV-") {
+
+                        if (startswith(dash, i)) {
+                                external = true;
+                                break;
+                        }
+                }
+                if (!external)
+                        continue;
+
+                /* Ignore ports that are not enabled */
+                enabled = udev_device_get_sysattr_value(d, "enabled");
+                if (!enabled)
+                        continue;
+                if (!streq_ptr(enabled, "enabled"))
+                        continue;
+
                 /* We count any connector which is not explicitly
                  * "disconnected" as connected. */
                 status = udev_device_get_sysattr_value(d, "status");
@@ -536,7 +571,7 @@ int manager_count_displays(Manager *m) {
         return n;
 }
 
-bool manager_is_docked_or_multiple_displays(Manager *m) {
+bool manager_is_docked_or_external_displays(Manager *m) {
         int n;
 
         /* If we are docked don't react to lid closing */
@@ -547,11 +582,11 @@ bool manager_is_docked_or_multiple_displays(Manager *m) {
 
         /* If we have more than one display connected,
          * assume that we are docked. */
-        n = manager_count_displays(m);
+        n = manager_count_external_displays(m);
         if (n < 0)
                 log_warning_errno(n, "Display counting failed: %m");
-        else if (n > 1) {
-                log_debug("Multiple (%i) displays connected.", n);
+        else if (n >= 1) {
+                log_debug("External (%i) displays connected.", n);
                 return true;
         }
 

diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c
index e6f9ec7845f3f793a6620296f6f8a494d1eed0f9..8ebcd3f5ca73ed5e891afeedd53c798429a57046 100644 (file)
--- a/src/login/logind-dbus.c
+++ b/src/login/logind-dbus.c
@@ -258,7 +258,7 @@ static int property_get_docked(
         assert(reply);
         assert(m);
 
-        return sd_bus_message_append(reply, "b", manager_is_docked_or_multiple_displays(m));
+        return sd_bus_message_append(reply, "b", manager_is_docked_or_external_displays(m));
 }
 
 static int method_get_session(sd_bus_message *message, void *userdata, sd_bus_error *error) {

diff --git a/src/login/logind.h b/src/login/logind.h
index cd226f55fc8cc5502b5256817aaa548114885716..feb381d0b11d03e1e7d10e9fb7be3d7571211d0f 100644 (file)
--- a/src/login/logind.h
+++ b/src/login/logind.h
@@ -156,9 +156,7 @@ int manager_get_idle_hint(Manager *m, dual_timestamp *t);
 int manager_get_user_by_pid(Manager *m, pid_t pid, User **user);
 int manager_get_session_by_pid(Manager *m, pid_t pid, Session **session);
 
-bool manager_is_docked(Manager *m);
-int manager_count_displays(Manager *m);
-bool manager_is_docked_or_multiple_displays(Manager *m);
+bool manager_is_docked_or_external_displays(Manager *m);
 
 extern const sd_bus_vtable manager_vtable[];