thunderbolt: Calculate DisplayPort tunnel bandwidth after DPRX capabi…

…lities read

[ Upstream commit ccd8450 ]

According to USB4 Connection Manager guide, after DisplayPort tunnel was
setup, the DPRX capabilities read is performed by the DPTX. According to
VESA spec, this shall be completed within 5 seconds after the DisplayPort
tunnel was setup. Hence, if the bit: DPRX Capabilities Read Done, was
not set to '1' by this time, we timeout and fail calculating DisplayPort
tunnel consumed bandwidth.

Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/thunderbolt/tunnel.c

@@ -1196,17 +1196,13 @@ static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
 		/*
 		 * Then see if the DPRX negotiation is ready and if yes
 		 * return that bandwidth (it may be smaller than the
-		 * reduced one). Otherwise return the remote (possibly
-		 * reduced) caps.
+		 * reduced one). According to VESA spec, the DPRX
+		 * negotiation shall compete in 5 seconds after tunnel
+		 * established. We give it 100ms extra just in case.
 		 */
-		ret = tb_dp_wait_dprx(tunnel, 150);
-		if (ret) {
-			if (ret == -ETIMEDOUT)
-				ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP,
-						     &rate, &lanes);
-			if (ret)
-				return ret;
-		}
+		ret = tb_dp_wait_dprx(tunnel, 5100);
+		if (ret)
+			return ret;
 		ret = tb_dp_read_cap(tunnel, DP_COMMON_CAP, &rate, &lanes);
 		if (ret)
 			return ret;