This may be helpful when debugging possible issues around DisplayPort
port tunneling.
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
drivers/thunderbolt/tunnel.c | 43 ++++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index 3ebd32b897a0..7df5f90e21d4 100644
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -1137,6 +1137,47 @@ static int tb_dp_init_video_path(struct tb_path *path)
return 0;
}
+static void tb_dp_dump(struct tb_tunnel *tunnel)
+{
+ struct tb_port *in, *out;
+ u32 dp_cap, rate, lanes;
+
+ in = tunnel->src_port;
+ out = tunnel->dst_port;
+
+ if (tb_port_read(in, &dp_cap, TB_CFG_PORT,
+ in->cap_adap + DP_LOCAL_CAP, 1))
+ return;
+
+ rate = tb_dp_cap_get_rate(dp_cap);
+ lanes = tb_dp_cap_get_lanes(dp_cap);
+
+ tb_port_dbg(in, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
+ rate, lanes, tb_dp_bandwidth(rate, lanes));
+
+ out = tunnel->dst_port;
+
+ if (tb_port_read(out, &dp_cap, TB_CFG_PORT,
+ out->cap_adap + DP_LOCAL_CAP, 1))
+ return;
+
+ rate = tb_dp_cap_get_rate(dp_cap);
+ lanes = tb_dp_cap_get_lanes(dp_cap);
+
+ tb_port_dbg(out, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
+ rate, lanes, tb_dp_bandwidth(rate, lanes));
+
+ if (tb_port_read(in, &dp_cap, TB_CFG_PORT,
+ in->cap_adap + DP_REMOTE_CAP, 1))
+ return;
+
+ rate = tb_dp_cap_get_rate(dp_cap);
+ lanes = tb_dp_cap_get_lanes(dp_cap);
+
+ tb_port_dbg(in, "reduced bandwidth %u Mb/s x%u = %u Mb/s\n",
+ rate, lanes, tb_dp_bandwidth(rate, lanes));
+}
+
/**
* tb_tunnel_discover_dp() - Discover existing Display Port tunnels
* @tb: Pointer to the domain structure
@@ -1214,6 +1255,8 @@ struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in,
goto err_deactivate;
}
+ tb_dp_dump(tunnel);
+
tb_tunnel_dbg(tunnel, "discovered\n");
return tunnel;
--
2.39.2
