plugin-manager: define a minimum probing time of 2s

Effectively, we're now letting the kernel up to 2s to show all the ports of the
device, starting from the time where the first port is exposed.

src/mm-plugin-manager.c

@@ -31,6 +31,9 @@
 /* Default time to defer probing checks */
 #define SUPPORTS_DEFER_TIMEOUT_SECS 3
 
+/* Time to wait for other ports to appear once the first port is exposed */
+#define MIN_PROBING_TIME_SECS 2
+
 static void initable_iface_init (GInitableIface *iface);
 
 G_DEFINE_TYPE_EXTENDED (MMPluginManager, mm_plugin_manager, G_TYPE_OBJECT, 0,
@@ -525,6 +528,7 @@ typedef struct {
     MMPluginManager *self;
     MMDevice *device;
     GSimpleAsyncResult *result;
+    guint timeout_id;
     gulong grabbed_id;
     gulong released_id;
 
@@ -546,6 +550,18 @@ port_probe_context_free (PortProbeContext *ctx)
 static void
 find_device_support_context_complete_and_free (FindDeviceSupportContext *ctx)
 {
+    g_assert (ctx->timeout_id == 0);
+
+    /* Set async operation result */
+    if (!mm_device_peek_plugin (ctx->device)) {
+        g_simple_async_result_set_error (ctx->result,
+                                         MM_CORE_ERROR,
+                                         MM_CORE_ERROR_UNSUPPORTED,
+                                         "not supported by any plugin");
+    } else {
+        g_simple_async_result_set_op_res_gboolean (ctx->result, TRUE);
+    }
+
     g_simple_async_result_complete (ctx->result);
 
     g_signal_handler_disconnect (ctx->device, ctx->grabbed_id);
@@ -619,17 +635,12 @@ find_port_support_ready (MMPluginManager *self,
     if (ctx->running_probes != NULL)
         return;
 
+    /* If we didn't use the minimum probing time, wait for it to finish */
+    if (ctx->timeout_id > 0)
+        return;
+
     /* If we just finished the last running probe, we can now finish the device
      * support check */
-    if (!mm_device_peek_plugin (ctx->device)) {
-        g_simple_async_result_set_error (ctx->result,
-                                         MM_CORE_ERROR,
-                                         MM_CORE_ERROR_UNSUPPORTED,
-                                         "not supported by any plugin");
-    } else {
-        g_simple_async_result_set_op_res_gboolean (ctx->result, TRUE);
-    }
-
     find_device_support_context_complete_and_free (ctx);
 }
 
@@ -674,6 +685,18 @@ device_port_released_cb (MMDevice *device,
             g_udev_device_get_name (port));
 }
 
+static gboolean
+min_probing_timeout_cb (FindDeviceSupportContext *ctx)
+{
+    ctx->timeout_id = 0;
+
+    /* If there are no running probes around, we're free to finish */
+    if (ctx->running_probes == NULL)
+        find_device_support_context_complete_and_free (ctx);
+
+    return FALSE;
+}
+
 void
 mm_plugin_manager_find_device_support (MMPluginManager *self,
                                        MMDevice *device,
@@ -699,6 +722,15 @@ mm_plugin_manager_find_device_support (MMPluginManager *self,
                                          MM_DEVICE_PORT_RELEASED,
                                          G_CALLBACK (device_port_released_cb),
                                          ctx);
+
+    /* Set the initial timeout of 2s. We force the probing time of the device to
+     * be at least this amount of time, so that the kernel has enough time to
+     * bring up ports. Given that we launch this only when the first port of the
+     * device has been exposed in udev, this timeout effectively means that we
+     * leave up to 2s to the remaining ports to appear. */
+    ctx->timeout_id = g_timeout_add_seconds (MIN_PROBING_TIME_SECS,
+                                             (GSourceFunc)min_probing_timeout_cb,
+                                             ctx);
 }
 
 /*****************************************************************************/