thunderbolt: Calculate DisplayPort tunnel bandwidth after DPRX capabilities read

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>

diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index e02b34654d296a68232d7130b1d844282b8f80ee..cb6609a56a03f9d1952707f1d42760de51838a9f 100644 (file)
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -1184,17 +1184,13 @@ 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;