Lots of random fixes:

Rework the MMCallbackInfo callback invocation.
Always use g_error_literal() where it makes sense.
Replace sleep() calls, with timeouts to not block the whole MM.

plugins/mm-modem-option.c

@@ -33,6 +33,18 @@ pin_check_done (MMModem *modem, GError *error, gpointer user_data)
     mm_callback_info_schedule (info);
 }
 
+static gboolean
+option_enabled (gpointer data)
+{
+    MMCallbackInfo *info = (MMCallbackInfo *) data;
+
+    /* Now check the PIN explicitly, option doesn't seem to report
+       that it needs it otherwise */
+    mm_generic_gsm_check_pin (MM_GENERIC_GSM (info->modem), pin_check_done, info);
+
+    return FALSE;
+}
+
 static void
 parent_enable_done (MMModem *modem, GError *error, gpointer user_data)
 {
@@ -43,11 +55,7 @@ parent_enable_done (MMModem *modem, GError *error, gpointer user_data)
     else if (GPOINTER_TO_INT (mm_callback_info_get_data (info, "option-enable"))) {
         /* Option returns OK on +CFUN=1 right away but needs some time
            to finish initialization */
-        sleep (10);
-
-        /* Now check the PIN explicitly, option doesn't seem to report
-           that it needs it otherwise */
-        mm_generic_gsm_check_pin (MM_GENERIC_GSM (modem), pin_check_done, info);
+        g_timeout_add_seconds (10, option_enabled, info);
         return;
     }
 
@@ -110,8 +118,8 @@ get_network_mode_done (MMSerial *serial,
     }
 
     if (!error && !parsed)
-        info->error = g_error_new (MM_MODEM_ERROR, MM_MODEM_ERROR_GENERAL,
-                                   "%s", "Could not parse network mode results");
+        info->error = g_error_new_literal (MM_MODEM_ERROR, MM_MODEM_ERROR_GENERAL,
+                                           "Could not parse network mode results");
 
     mm_callback_info_schedule (info);
 }