thunderbolt: dma_test: Use correct value for absent rings when creating paths

Both tb_xdomain_enable_paths() and tb_xdomain_disable_paths() expect -1,
not 0, if the corresponding ring is not needed. For this reason change
the driver to use correct value for the rings that are not needed.

Fixes: 180b068942 ("thunderbolt: Allow multiple DMA tunnels over a single XDomain connection")
Cc: stable@vger.kernel.org
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/dma_test.c

@@ -192,9 +192,9 @@ static int dma_test_start_rings(struct dma_test *dt)
 	}
 
 	ret = tb_xdomain_enable_paths(dt->xd, dt->tx_hopid,
-				      dt->tx_ring ? dt->tx_ring->hop : 0,
+				      dt->tx_ring ? dt->tx_ring->hop : -1,
 				      dt->rx_hopid,
-				      dt->rx_ring ? dt->rx_ring->hop : 0);
+				      dt->rx_ring ? dt->rx_ring->hop : -1);
 	if (ret) {
 		dma_test_free_rings(dt);
 		return ret;
@@ -218,9 +218,9 @@ static void dma_test_stop_rings(struct dma_test *dt)
 		tb_ring_stop(dt->tx_ring);
 
 	ret = tb_xdomain_disable_paths(dt->xd, dt->tx_hopid,
-				       dt->tx_ring ? dt->tx_ring->hop : 0,
+				       dt->tx_ring ? dt->tx_ring->hop : -1,
 				       dt->rx_hopid,
-				       dt->rx_ring ? dt->rx_ring->hop : 0);
+				       dt->rx_ring ? dt->rx_ring->hop : -1);
 	if (ret)
 		dev_warn(&dt->svc->dev, "failed to disable DMA paths\n");