thunderbolt: Increase runtime PM reference count on DP tunnel discovery

If the driver is unbound and then bound back it goes over the topology
and figure out the existing tunnels. However, if it finds DP tunnel it
should make sure the domain does not runtime suspend as otherwise it
will tear down the DP tunnel unexpectedly.

Fixes: 6ac6faee5d7d ("thunderbolt: Add runtime PM for Software CM")
Cc: stable@vger.kernel.org
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 1f000ac1728b9a15269ceef1de9223263432e65c..c348b1fc0efc3f84477f1a02921118e274cf300f 100644 (file)
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -138,6 +138,10 @@ static void tb_discover_tunnels(struct tb_switch *sw)
                                parent->boot = true;
                                parent = tb_switch_parent(parent);
                        }
+               } else if (tb_tunnel_is_dp(tunnel)) {
+                       /* Keep the domain from powering down */
+                       pm_runtime_get_sync(&tunnel->src_port->sw->dev);
+                       pm_runtime_get_sync(&tunnel->dst_port->sw->dev);
                }
 
                list_add_tail(&tunnel->list, &tcm->tunnel_list);