void tb_ring_start()

in nhi.c [616:683]

• 54 lines of code
• 7 McCabe index (conditional complexity)

void tb_ring_start(struct tb_ring *ring)
{
	u16 frame_size;
	u32 flags;

	spin_lock_irq(&ring->nhi->lock);
	spin_lock(&ring->lock);
	if (ring->nhi->going_away)
		goto err;
	if (ring->running) {
		dev_WARN(&ring->nhi->pdev->dev, "ring already started\n");
		goto err;
	}
	dev_dbg(&ring->nhi->pdev->dev, "starting %s %d\n",
		RING_TYPE(ring), ring->hop);

	if (ring->flags & RING_FLAG_FRAME) {
		/* Means 4096 */
		frame_size = 0;
		flags = RING_FLAG_ENABLE;
	} else {
		frame_size = TB_FRAME_SIZE;
		flags = RING_FLAG_ENABLE | RING_FLAG_RAW;
	}

	ring_iowrite64desc(ring, ring->descriptors_dma, 0);
	if (ring->is_tx) {
		ring_iowrite32desc(ring, ring->size, 12);
		ring_iowrite32options(ring, 0, 4); /* time releated ? */
		ring_iowrite32options(ring, flags, 0);
	} else {
		u32 sof_eof_mask = ring->sof_mask << 16 | ring->eof_mask;

		ring_iowrite32desc(ring, (frame_size << 16) | ring->size, 12);
		ring_iowrite32options(ring, sof_eof_mask, 4);
		ring_iowrite32options(ring, flags, 0);
	}

	/*
	 * Now that the ring valid bit is set we can configure E2E if
	 * enabled for the ring.
	 */
	if (ring->flags & RING_FLAG_E2E) {
		if (!ring->is_tx) {
			u32 hop;

			hop = ring->e2e_tx_hop << REG_RX_OPTIONS_E2E_HOP_SHIFT;
			hop &= REG_RX_OPTIONS_E2E_HOP_MASK;
			flags |= hop;

			dev_dbg(&ring->nhi->pdev->dev,
				"enabling E2E for %s %d with TX HopID %d\n",
				RING_TYPE(ring), ring->hop, ring->e2e_tx_hop);
		} else {
			dev_dbg(&ring->nhi->pdev->dev, "enabling E2E for %s %d\n",
				RING_TYPE(ring), ring->hop);
		}

		flags |= RING_FLAG_E2E_FLOW_CONTROL;
		ring_iowrite32options(ring, flags, 0);
	}

	ring_interrupt_active(ring, true);
	ring->running = true;
err:
	spin_unlock(&ring->lock);
	spin_unlock_irq(&ring->nhi->lock);
}