It turns out that when plugging in VGA cable through USB-C to VGA/DVI dongle the Connection Manager handshake can take longer time, at least on Intel Titan Ridge based docks such as Dell WD91TB. This leads to following error in the dmesg: thunderbolt 0000:00:0d.3: 3:10: DP tunnel activation failed, aborting and the display stays blank (because we failed to establish the tunnel). For this reason increase the timeout to 3s. Reported-by: Koba Ko <koba.ko@xxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> --- drivers/thunderbolt/tunnel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c index 3bf2628a5dcd..3ebd32b897a0 100644 --- a/drivers/thunderbolt/tunnel.c +++ b/drivers/thunderbolt/tunnel.c @@ -531,7 +531,7 @@ static int tb_dp_xchg_caps(struct tb_tunnel *tunnel) * Perform connection manager handshake between IN and OUT ports * before capabilities exchange can take place. */ - ret = tb_dp_cm_handshake(in, out, 1500); + ret = tb_dp_cm_handshake(in, out, 3000); if (ret) return ret; -- 2.39.2
