From 69eb79f7d294f92696de8010432758dbd3d1ecb3 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Wed, 29 Apr 2020 17:00:30 +0300 Subject: thunderbolt: Make tb_next_port_on_path() work with tree topologies USB4 makes it possible to have tree topology of devices connected in the same way than USB3. This was actually possible in Thunderbolt 1, 2 and 3 as well but all the available devices only had two ports which allows building only daisy-chains of devices. With USB4 it is possible for example that there is DP IN adapter as part of eGPU device router and that should be tunneled over the tree topology to a DP OUT adapter. This updates the tb_next_port_on_path() to support such topologies. Signed-off-by: Mika Westerberg --- drivers/thunderbolt/switch.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'drivers/thunderbolt') diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c index 95b75a712ade..29db484d2c74 100644 --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -850,6 +850,13 @@ void tb_port_release_out_hopid(struct tb_port *port, int hopid) ida_simple_remove(&port->out_hopids, hopid); } +static inline bool tb_switch_is_reachable(const struct tb_switch *parent, + const struct tb_switch *sw) +{ + u64 mask = (1ULL << parent->config.depth * 8) - 1; + return (tb_route(parent) & mask) == (tb_route(sw) & mask); +} + /** * tb_next_port_on_path() - Return next port for given port on a path * @start: Start port of the walk @@ -879,12 +886,12 @@ struct tb_port *tb_next_port_on_path(struct tb_port *start, struct tb_port *end, return end; } - if (start->sw->config.depth < end->sw->config.depth) { + if (tb_switch_is_reachable(prev->sw, end->sw)) { + next = tb_port_at(tb_route(end->sw), prev->sw); + /* Walk down the topology if next == prev */ if (prev->remote && - prev->remote->sw->config.depth > prev->sw->config.depth) + (next == prev || next->dual_link_port == prev)) next = prev->remote; - else - next = tb_port_at(tb_route(end->sw), prev->sw); } else { if (tb_is_upstream_port(prev)) { next = prev->remote; @@ -901,7 +908,7 @@ struct tb_port *tb_next_port_on_path(struct tb_port *start, struct tb_port *end, } } - return next; + return next != prev ? next : NULL; } static int tb_port_get_link_speed(struct tb_port *port) -- cgit v1.2.3