From 033c2d8ab2835a7f13e1a9c6813b412935e77140 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Wed, 24 May 2023 14:03:55 +0300 Subject: thunderbolt: Log DisplayPort adapter rate and lanes on discovery This may be helpful when debugging possible issues around DisplayPort port tunneling. Signed-off-by: Mika Westerberg --- drivers/thunderbolt/tunnel.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'drivers/thunderbolt/tunnel.c') diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c index 3bf2628a5dcd..527fef43b2e9 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; -- cgit v1.2.3