static ssize_t extts_fifo_show()

in ptp_sysfs.c [63:94]

• 27 lines of code
• 4 McCabe index (conditional complexity)

static ssize_t extts_fifo_show(struct device *dev,
			       struct device_attribute *attr, char *page)
{
	struct ptp_clock *ptp = dev_get_drvdata(dev);
	struct timestamp_event_queue *queue = &ptp->tsevq;
	struct ptp_extts_event event;
	unsigned long flags;
	size_t qcnt;
	int cnt = 0;

	memset(&event, 0, sizeof(event));

	if (mutex_lock_interruptible(&ptp->tsevq_mux))
		return -ERESTARTSYS;

	spin_lock_irqsave(&queue->lock, flags);
	qcnt = queue_cnt(queue);
	if (qcnt) {
		event = queue->buf[queue->head];
		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
	}
	spin_unlock_irqrestore(&queue->lock, flags);

	if (!qcnt)
		goto out;

	cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
		       event.index, event.t.sec, event.t.nsec);
out:
	mutex_unlock(&ptp->tsevq_mux);
	return cnt;
}