[PATCH v3 07/18] thunderbolt: Handle rejected Thunderbolt devices

From: Mika Westerberg
Date: Fri Mar 02 2018 - 07:40:35 EST


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@xxxxxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
---
drivers/thunderbolt/icm.c | 6 ++++++
drivers/thunderbolt/tb_msgs.h | 1 +
2 files changed, 7 insertions(+)

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;
--
2.16.1