broadband-modem: track primary/secondary ports while enabling/disabling 3GPP URCs

We should not blindly assume that peek_port_primary() always returns a
valid port, because the device may have been ejected while the AT
sequence is running.

Instead, keep a valid port object reference in the operation context,
and use it in all the AT command requests. The requests will fail if
the device has been ejected, but the port object reference will be
valid and the daemon won't crash.

src/mm-broadband-modem.c

@@ -5461,6 +5461,8 @@ modem_3gpp_create_initial_eps_bearer (MMIfaceModem3gpp   *self,
 /* Enable/Disable unsolicited registration events (3GPP interface) */
 
 typedef struct {
+    MMPortSerialAt *primary;
+    MMPortSerialAt *secondary; /* optional */
     gboolean enable; /* TRUE for enabling, FALSE for disabling */
     gboolean run_cs;
     gboolean run_ps;
@@ -5478,6 +5480,8 @@ typedef struct {
 static void
 unsolicited_registration_events_context_free (UnsolicitedRegistrationEventsContext *ctx)
 {
+    g_clear_object (&ctx->primary);
+    g_clear_object (&ctx->secondary);
     if (ctx->cs_error)
         g_error_free (ctx->cs_error);
     if (ctx->ps_error)
@@ -5504,6 +5508,8 @@ unsolicited_registration_events_task_new (MMBroadbandModem *self,
     ctx->run_cs = cs_supported;
     ctx->run_ps = ps_supported;
     ctx->run_eps = eps_supported;
+    ctx->primary = mm_base_modem_get_port_primary (MM_BASE_MODEM (self));
+    ctx->secondary = mm_base_modem_get_port_secondary (MM_BASE_MODEM (self));
 
     task = g_task_new (self, NULL, callback, user_data);
     g_task_set_task_data (task,
@@ -5595,7 +5601,6 @@ unsolicited_registration_events_sequence_ready (MMBroadbandModem *self,
     UnsolicitedRegistrationEventsContext *ctx;
     GError *error = NULL;
     GVariant *command;
-    MMPortSerialAt *secondary;
 
     ctx = g_task_get_task_data (task);
 
@@ -5664,8 +5669,7 @@ unsolicited_registration_events_sequence_ready (MMBroadbandModem *self,
         /* Even if primary failed, go on and try to enable in secondary port */
     }
 
-    secondary = mm_base_modem_peek_port_secondary (MM_BASE_MODEM (self));
-    if (secondary) {
+    if (ctx->secondary) {
         const MMBaseModemAtCommand *registration_sequence = NULL;
 
         ctx->secondary_done = TRUE;
@@ -5674,7 +5678,7 @@ unsolicited_registration_events_sequence_ready (MMBroadbandModem *self,
         if (command) {
             mm_base_modem_at_command_full (
                 MM_BASE_MODEM (self),
-                secondary,
+                ctx->secondary,
                 g_variant_get_string (command, NULL),
                 3,
                 FALSE,
@@ -5695,7 +5699,7 @@ unsolicited_registration_events_sequence_ready (MMBroadbandModem *self,
             registration_sequence = ctx->enable ? eps_registration_sequence : eps_unregistration_sequence;
         mm_base_modem_at_sequence_full (
             MM_BASE_MODEM (self),
-            secondary,
+            ctx->secondary,
             registration_sequence,
             NULL,  /* response processor context */
             NULL,  /* response processor context free */
@@ -5729,7 +5733,7 @@ unsolicited_registration_events_context_step (GTask *task)
         ctx->run_cs = FALSE;
         mm_base_modem_at_sequence_full (
             MM_BASE_MODEM (self),
-            mm_base_modem_peek_port_primary (MM_BASE_MODEM (self)),
+            ctx->primary,
             ctx->enable ? cs_registration_sequence : cs_unregistration_sequence,
             NULL,  /* response processor context */
             NULL,  /* response processor context free */
@@ -5744,7 +5748,7 @@ unsolicited_registration_events_context_step (GTask *task)
         ctx->run_ps = FALSE;
         mm_base_modem_at_sequence_full (
             MM_BASE_MODEM (self),
-            mm_base_modem_peek_port_primary (MM_BASE_MODEM (self)),
+            ctx->primary,
             ctx->enable ? ps_registration_sequence : ps_unregistration_sequence,
             NULL,  /* response processor context */
             NULL,  /* response processor context free */
@@ -5759,7 +5763,7 @@ unsolicited_registration_events_context_step (GTask *task)
         ctx->run_eps = FALSE;
         mm_base_modem_at_sequence_full (
             MM_BASE_MODEM (self),
-            mm_base_modem_peek_port_primary (MM_BASE_MODEM (self)),
+            ctx->primary,
             ctx->enable ? eps_registration_sequence : eps_unregistration_sequence,
             NULL,  /* response processor context */
             NULL,  /* response processor context free */