1 files changed, 20 insertions, 1 deletions

diff --git a/drivers/thunderbolt/path.c b/drivers/thunderbolt/path.c
index 8fcf8a7b6c22..9562cd026dc0 100644
--- a/drivers/thunderbolt/path.c
+++ b/drivers/thunderbolt/path.c
@@ -150,7 +150,26 @@ int tb_path_activate(struct tb_path *path)
 
         /* Activate hops. */
         for (i = path->path_length - 1; i >= 0; i--) {
-                struct tb_regs_hop hop;
+                struct tb_regs_hop hop = { 0 };
+
+                /*
+                 * We do (currently) not tear down paths setup by the firmeware.
+                 * If a firmware device is unplugged and plugged in again then
+                 * it can happen that we reuse some of the hops from the (now
+                 * defunct) firmeware path. This causes the hotplug operation to
+                 * fail (the pci device does not show up). Clearing the hop
+                 * before overwriting it fixes the problem.
+                 *
+                 * Should be removed once we discover and tear down firmeware
+                 * paths.
+                 */
+                res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,
+                                    2 * path->hops[i].in_hop_index, 2);
+                if (res) {
+                        __tb_path_deactivate_hops(path, i);
+                        __tb_path_deallocate_nfc(path, 0);
+                        goto err;
+                }
 
                 /* dword 0 */
                 hop.next_hop = path->hops[i].next_hop_index;