pio_complete
ret = pio_complete(dev, buffer, size);
ret = pio_complete(dev, NULL, NULL);
ret = pio_complete(dev, buffer, actual_size);
ret = pio_complete(dev, NULL, NULL);
ret = pio_complete(dev, read_buffer, actual_size);
struct completion pio_complete;
complete(&host->pio_complete);
complete(&host->pio_complete);
complete(&host->pio_complete);
init_completion(&host->pio_complete);
wait_for_completion_interruptible_timeout(&host->pio_complete,