static void hci_dma_xfer_done()

in master/mipi-i3c-hci/dma.c [495:539]

• 38 lines of code
• 6 McCabe index (conditional complexity)

static void hci_dma_xfer_done(struct i3c_hci *hci, struct hci_rh_data *rh)
{
	u32 op1_val, op2_val, resp, *ring_resp;
	unsigned int tid, done_ptr = rh->done_ptr;
	struct hci_xfer *xfer;

	for (;;) {
		op2_val = rh_reg_read(RING_OPERATION2);
		if (done_ptr == FIELD_GET(RING_OP2_CR_DEQ_PTR, op2_val))
			break;

		ring_resp = rh->resp + rh->resp_struct_sz * done_ptr;
		resp = *ring_resp;
		tid = RESP_TID(resp);
		DBG("resp = 0x%08x", resp);

		xfer = rh->src_xfers[done_ptr];
		if (!xfer) {
			DBG("orphaned ring entry");
		} else {
			hci_dma_unmap_xfer(hci, xfer, 1);
			xfer->ring_entry = -1;
			xfer->response = resp;
			if (tid != xfer->cmd_tid) {
				dev_err(&hci->master.dev,
					"response tid=%d when expecting %d\n",
					tid, xfer->cmd_tid);
				/* TODO: do something about it? */
			}
			if (xfer->completion)
				complete(xfer->completion);
		}

		done_ptr = (done_ptr + 1) % rh->xfer_entries;
		rh->done_ptr = done_ptr;
	}

	/* take care to update the software dequeue pointer atomically */
	spin_lock(&rh->lock);
	op1_val = rh_reg_read(RING_OPERATION1);
	op1_val &= ~RING_OP1_CR_SW_DEQ_PTR;
	op1_val |= FIELD_PREP(RING_OP1_CR_SW_DEQ_PTR, done_ptr);
	rh_reg_write(RING_OPERATION1, op1_val);
	spin_unlock(&rh->lock);
}