[PATCH 3/3] bearer-mbim: check if IP session is activated before deactivating it

[Ben Chan]

It may be undesirable to issue a MBIM_CID_CONNECT
(MBIMActivationCommandDeactivate) command to deactivate an IP session
when the session isn't activated. For instance, it's been observed on
Huawei ME936 that it takes more than 30s for the modem to deactivate a
not-yet-activated session. This patch modifies MMBearerMbim to query if
a session is activated before trying to deactivate the session during a
connection attempt.
---
 src/mm-bearer-mbim.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)

diff --git a/src/mm-bearer-mbim.c b/src/mm-bearer-mbim.c
index f7c721b6..652f6825 100644
--- a/src/mm-bearer-mbim.c
+++ b/src/mm-bearer-mbim.c
@@ -211,6 +211,7 @@ typedef enum {
     CONNECT_STEP_FIRST,
     CONNECT_STEP_PACKET_SERVICE,
     CONNECT_STEP_PROVISIONED_CONTEXTS,
+    CONNECT_STEP_CHECK_DISCONNECTED,
     CONNECT_STEP_ENSURE_DISCONNECTED,
     CONNECT_STEP_CONNECT,
     CONNECT_STEP_IP_CONFIGURATION,
@@ -644,6 +645,53 @@ ensure_disconnected_ready (MbimDevice   *device,
     connect_context_step (task);
 }
 
+static void
+check_disconnected_ready (MbimDevice   *device,
+                          GAsyncResult *res,
+                          GTask        *task)
+{
+    ConnectContext *ctx;
+    GError *error = NULL;
+    MbimMessage *response;
+    guint32 session_id;
+    MbimActivationState activation_state;
+
+    ctx = g_task_get_task_data (task);
+
+    response = mbim_device_command_finish (device, res, &error);
+    if (response &&
+        mbim_message_response_get_result (response, MBIM_MESSAGE_TYPE_COMMAND_DONE, &error) &&
+        mbim_message_connect_response_parse (
+            response,
+            &session_id,
+            &activation_state,
+            NULL, /* voice_call_state */
+            NULL, /* ip_type */
+            NULL, /* context_type */
+            NULL, /* nw_error */
+            &error)) {
+        mm_dbg ("Session ID '%u': %s", session_id, mbim_activation_state_get_string (activation_state));
+    } else
+        activation_state = MBIM_ACTIVATION_STATE_UNKNOWN;
+
+    if (response)
+        mbim_message_unref (response);
+
+    /* Some modem (e.g. Huawei ME936) reports MBIM_ACTIVATION_STATE_UNKNOWN
+     * when being queried for the activation state before an IP session has
+     * been activated once. Here we expect a modem would at least tell the
+     * truth when the session has been activated, so we proceed to deactivate
+     * the session only the modem indicates the session has been activated or
+     * is being activated.
+     */
+    if (activation_state == MBIM_ACTIVATION_STATE_ACTIVATED || activation_state == MBIM_ACTIVATION_STATE_ACTIVATING)
+        ctx->step = CONNECT_STEP_ENSURE_DISCONNECTED;
+    else
+        ctx->step = CONNECT_STEP_CONNECT;
+
+    connect_context_step (task);
+}
+
 static void
 provisioned_contexts_query_ready (MbimDevice *device,
                                   GAsyncResult *res,
@@ -829,6 +877,33 @@ connect_context_step (GTask *task)
         mbim_message_unref (message);
         return;
 
+    case CONNECT_STEP_CHECK_DISCONNECTED: {
+        GError *error = NULL;
+
+        message = (mbim_message_connect_query_new (
+                       self->priv->session_id,
+                       MBIM_ACTIVATION_STATE_UNKNOWN,
+                       MBIM_VOICE_CALL_STATE_NONE,
+                       MBIM_CONTEXT_IP_TYPE_DEFAULT,
+                       mbim_uuid_from_context_type (MBIM_CONTEXT_TYPE_INTERNET),
+                       0,
+                       &error));
+        if (!message) {
+            g_task_return_error (task, error);
+            g_object_unref (task);
+            return;
+        }
+
+        mbim_device_command (ctx->device,
+                             message,
+                             10,
+                             NULL,
+                             (GAsyncReadyCallback)check_disconnected_ready,
+                             task);
+        mbim_message_unref (message);
+        return;
+    }
+
     case CONNECT_STEP_ENSURE_DISCONNECTED: {
         GError *error = NULL;
 
-- 
2.16.0.rc1.238.g530d649a79-goog