thunderbolt: Handle rejected Thunderbolt devices

The ICM firmware rejects devices if the maximum topology limit is
exceeded (more than 6 devices are connected). If that happens just log a
message to the kernel message buffer and bail out.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

2 files changed, 7 insertions, 0 deletions

diff --git a/drivers/thunderbolt/icm.c b/drivers/thunderbolt/icm.c
index 611d28e8e5f2..6d7f8262f864 100644
--- a/drivers/thunderbolt/icm.c
+++ b/drivers/thunderbolt/icm.c
@@ -410,6 +410,12 @@ icm_fr_device_connected(struct tb *tb, const struct icm_pkg_header *hdr)
                 ICM_LINK_INFO_DEPTH_SHIFT;
         authorized = pkg->link_info & ICM_LINK_INFO_APPROVED;
 
+        if (pkg->link_info & ICM_LINK_INFO_REJECTED) {
+                tb_info(tb, "switch at %u.%u was rejected by ICM firmware because topology limit exceeded\n",
+                        link, depth);
+                return;
+        }
+
         ret = icm->get_route(tb, link, depth, &route);
         if (ret) {
                 tb_err(tb, "failed to find route string for switch at %u.%u\n",
diff --git a/drivers/thunderbolt/tb_msgs.h b/drivers/thunderbolt/tb_msgs.h
index b0a092baa605..476bc04cac6c 100644
--- a/drivers/thunderbolt/tb_msgs.h
+++ b/drivers/thunderbolt/tb_msgs.h
@@ -176,6 +176,7 @@ struct icm_fr_event_device_connected {
 #define ICM_LINK_INFO_DEPTH_SHIFT       4
 #define ICM_LINK_INFO_DEPTH_MASK        GENMASK(7, 4)
 #define ICM_LINK_INFO_APPROVED          BIT(8)
+#define ICM_LINK_INFO_REJECTED          BIT(9)
 
 struct icm_fr_pkg_approve_device {
         struct icm_pkg_header hdr;