diff mbox series

thunderbolt: Log DisplayPort adapter rate and lanes on discovery

Message ID 20230526110037.20542-1-mika.westerberg@linux.intel.com (mailing list archive)
State Accepted
Commit 033c2d8ab2835a7f13e1a9c6813b412935e77140
Headers show
Series thunderbolt: Log DisplayPort adapter rate and lanes on discovery | expand

Commit Message

Mika Westerberg May 26, 2023, 11 a.m. UTC 
This may be helpful when debugging possible issues around DisplayPort
port tunneling.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/thunderbolt/tunnel.c | 43 ++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

Comments

Mika Westerberg May 30, 2023, 6:15 a.m. UTC | #1 
On Fri, May 26, 2023 at 02:00:37PM +0300, Mika Westerberg wrote:
> This may be helpful when debugging possible issues around DisplayPort
> port tunneling.
> 
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Applied to thunderbolt.git/next.
diff mbox series

Patch

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;