modem: allow periodic signal check to be disabled

ModemManager decides to disable periodic signal check if either
load_signal_quality is not implemented or load_signal_quality returns an
unsupported error. However, in some cases, we want to use
load_signal_quality to query the initial signal quality but rely on
unsolicited signal quality updates from the modem afterwards without
periodically polling for signal quality. To support that, this patch
introduces a property in MMIfaceModem/MMBroadbandModem to indicate if
the periodic signal check should be disabled.

src/mm-broadband-modem.c

@@ -117,6 +117,7 @@ enum {
     PROP_MODEM_SIMPLE_STATUS,
     PROP_MODEM_SIM_HOT_SWAP_SUPPORTED,
     PROP_MODEM_SIM_HOT_SWAP_CONFIGURED,
+    PROP_MODEM_PERIODIC_SIGNAL_CHECK_DISABLED,
     PROP_FLOW_CONTROL,
     PROP_LAST
 };
@@ -136,6 +137,7 @@ struct _MMBroadbandModemPrivate {
     gboolean modem_init_run;
     gboolean sim_hot_swap_supported;
     gboolean sim_hot_swap_configured;
+    gboolean periodic_signal_check_disabled;
 
     /*<--- Modem interface --->*/
     /* Properties */
@@ -10809,6 +10811,9 @@ set_property (GObject *object,
     case PROP_MODEM_SIM_HOT_SWAP_CONFIGURED:
         self->priv->sim_hot_swap_configured = g_value_get_boolean (value);
         break;
+    case PROP_MODEM_PERIODIC_SIGNAL_CHECK_DISABLED:
+        self->priv->periodic_signal_check_disabled = g_value_get_boolean (value);
+        break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
         break;
@@ -10917,6 +10922,9 @@ get_property (GObject *object,
     case PROP_MODEM_SIM_HOT_SWAP_CONFIGURED:
         g_value_set_boolean (value, self->priv->sim_hot_swap_configured);
         break;
+    case PROP_MODEM_PERIODIC_SIGNAL_CHECK_DISABLED:
+        g_value_set_boolean (value, self->priv->periodic_signal_check_disabled);
+        break;
     case PROP_FLOW_CONTROL:
         g_value_set_flags (value, self->priv->flow_control);
         break;
@@ -10949,6 +10957,7 @@ mm_broadband_modem_init (MMBroadbandModem *self)
     self->priv->current_sms_mem1_storage = MM_SMS_STORAGE_UNKNOWN;
     self->priv->current_sms_mem2_storage = MM_SMS_STORAGE_UNKNOWN;
     self->priv->sim_hot_swap_supported = FALSE;
+    self->priv->periodic_signal_check_disabled = FALSE;
     self->priv->modem_cmer_enable_mode = MM_3GPP_CMER_MODE_NONE;
     self->priv->modem_cmer_disable_mode = MM_3GPP_CMER_MODE_NONE;
     self->priv->modem_cmer_ind = MM_3GPP_CMER_IND_NONE;
@@ -11430,6 +11439,11 @@ mm_broadband_modem_class_init (MMBroadbandModemClass *klass)
     g_object_class_override_property (object_class,
                                       PROP_MODEM_SIM_HOT_SWAP_CONFIGURED,
                                       MM_IFACE_MODEM_SIM_HOT_SWAP_CONFIGURED);
+
+    g_object_class_override_property (object_class,
+                                      PROP_MODEM_PERIODIC_SIGNAL_CHECK_DISABLED,
+                                      MM_IFACE_MODEM_PERIODIC_SIGNAL_CHECK_DISABLED);
+
     properties[PROP_FLOW_CONTROL] =
         g_param_spec_flags (MM_BROADBAND_MODEM_FLOW_CONTROL,
                             "Flow control",

src/mm-iface-modem.c

@@ -1263,15 +1263,6 @@ peridic_signal_check_step (MMIfaceModem *self)
             return;
         }
 
-        /* If both tasks are unsupported, implicitly disable. Do NOT clear the
-         * values, because if we're told they are unsupported it may be that
-         * they're really updated via unsolicited messages. */
-        if (!ctx->access_technology_polling_supported && !ctx->signal_quality_polling_supported) {
-            mm_dbg ("Periodic signal checks not supported");
-            periodic_signal_check_disable (self, FALSE);
-            return;
-        }
-
         /* Schedule when we poll next time.
          * Initially we poll at a higher frequency until we get valid signal
          * quality and access technology values. As soon as we get them, OR if
@@ -1280,6 +1271,7 @@ peridic_signal_check_step (MMIfaceModem *self)
         if (ctx->interval == SIGNAL_CHECK_INITIAL_TIMEOUT_SEC) {
             gboolean signal_quality_ready;
             gboolean access_technology_ready;
+            gboolean initial_check_done;
 
             /* Signal quality is ready if unsupported or if we got a valid
              * value reported */
@@ -1289,15 +1281,33 @@ peridic_signal_check_step (MMIfaceModem *self)
             access_technology_ready = (!ctx->access_technology_polling_supported ||
                                        ((ctx->access_technologies & ctx->access_technologies_mask) != MM_MODEM_ACCESS_TECHNOLOGY_UNKNOWN));
 
-            if (signal_quality_ready && access_technology_ready) {
+            initial_check_done = ((signal_quality_ready && access_technology_ready) ||
-                mm_dbg ("Initial signal quality and access technology ready: fallback to default frequency");
+                                  (--ctx->initial_retries == 0));
-                ctx->interval = SIGNAL_CHECK_TIMEOUT_SEC;
+            if (initial_check_done) {
-            } else if (--ctx->initial_retries == 0) {
+                gboolean periodic_signal_check_disabled = FALSE;
-                mm_dbg ("Too many periodic signal checks at high frequency: fallback to default frequency");
+
+                g_object_get (self,
+                              MM_IFACE_MODEM_PERIODIC_SIGNAL_CHECK_DISABLED,
+                              &periodic_signal_check_disabled,
+                              NULL);
+                /* If periodic signal check is disabled, treat it as
+                 * unsupported after the initial check is done. */
+                if (periodic_signal_check_disabled)
+                    ctx->signal_quality_polling_supported = FALSE;
+
                 ctx->interval = SIGNAL_CHECK_TIMEOUT_SEC;
             }
         }
 
+        /* If both tasks are unsupported, implicitly disable. Do NOT clear the
+         * values, because if we're told they are unsupported it may be that
+         * they're really updated via unsolicited messages. */
+        if (!ctx->access_technology_polling_supported && !ctx->signal_quality_polling_supported) {
+            mm_dbg ("Periodic signal and access technologies checks not supported");
+            periodic_signal_check_disable (self, FALSE);
+            return;
+        }
+
         mm_dbg ("Periodic signal quality checks scheduled in %ds", ctx->interval);
         g_assert (!ctx->timeout_source);
         ctx->timeout_source = g_timeout_add_seconds (ctx->interval, (GSourceFunc) periodic_signal_check_cb, self);
@@ -5366,6 +5376,15 @@ iface_modem_init (gpointer g_iface)
                                "Whether the sim hot swap support is configured correctly.",
                                FALSE,
                                G_PARAM_READWRITE));
+
+    g_object_interface_install_property
+        (g_iface,
+         g_param_spec_boolean (MM_IFACE_MODEM_PERIODIC_SIGNAL_CHECK_DISABLED,
+                               "Periodic signal check disabled",
+                               "Whether periodic signal check is disabled.",
+                               FALSE,
+                               G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
+
     initialized = TRUE;
 }
 

src/mm-iface-modem.h

@@ -38,6 +38,7 @@
 #define MM_IFACE_MODEM_BEARER_LIST             "iface-modem-bearer-list"
 #define MM_IFACE_MODEM_SIM_HOT_SWAP_SUPPORTED  "iface-modem-sim-hot-swap-supported"
 #define MM_IFACE_MODEM_SIM_HOT_SWAP_CONFIGURED "iface-modem-sim-hot-swap-configured"
+#define MM_IFACE_MODEM_PERIODIC_SIGNAL_CHECK_DISABLED "iface-modem-periodic-signal-check-disabled"
 
 typedef struct _MMIfaceModem MMIfaceModem;