pt_cmd_callback
cmd->pt_cmd_callback(cmd->data, cmd->ret);
cmd->pt_cmd_callback(cmd->data, cmd->ret);
cmd->pt_cmd_callback(cmd->data, -ENODEV);
pt_cmd->pt_cmd_callback = pt_cmd_callback;
pt_cmd->pt_cmd_callback = pt_cmd_callback_work;
pt_cmd_callback(desc, 0);
pt_cmd_callback(desc, 0);
void (*pt_cmd_callback)(void *data, int err);