struct comedi_cmd *cmd)
 {
        int err = 0;
-       int tmp;
+       unsigned int arg;
 
        /* Step 1 : check if triggers are trivially valid */
 
        /* step 4: fix up any arguments */
 
        if (cmd->scan_begin_src == TRIG_TIMER) {
-               tmp = cmd->scan_begin_arg;
+               arg = cmd->scan_begin_arg;
                /* round to nearest microsec */
-               cmd->scan_begin_arg =
-                   nano_per_micro * ((tmp +
-                                      (nano_per_micro / 2)) / nano_per_micro);
-               if (tmp != cmd->scan_begin_arg)
-                       err++;
+               arg = nano_per_micro *
+                     ((arg + (nano_per_micro / 2)) / nano_per_micro);
+               err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, arg);
        }
        if (cmd->convert_src == TRIG_TIMER) {
-               tmp = cmd->convert_arg;
+               arg = cmd->convert_arg;
                /* round to nearest microsec */
-               cmd->convert_arg =
-                   nano_per_micro * ((tmp +
-                                      (nano_per_micro / 2)) / nano_per_micro);
-               if (tmp != cmd->convert_arg)
-                       err++;
+               arg = nano_per_micro *
+                     ((arg + (nano_per_micro / 2)) / nano_per_micro);
+               err |= cfc_check_trigger_arg_is(&cmd->convert_arg, arg);
        }
 
        if (err)