drm/i915: Sanitize the TypeC connect/detect sequences

Make the order during detection more consistent: first reset the TypeC
port mode if needed (adding new helpers for this), then detect any
connected sink.

To check if a port mode reset is needed determine first the target port
mode based on the live status if a sink is already connected or the
PHY status complete flag otherwise.

Add a WARN in legacy mode if unexpectedly we can't set the unsafe mode
or if the FIA doesn't provide the 4 lanes required.

Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190628143635.22066-13-imre.deak@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
index 96855250a5be2823038bad1ef8aca35f69cba435..f63ddf39b369872b375a656c98dc6dabfb221a79 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_tc.c
+++ b/drivers/gpu/drm/i915/display/intel_tc.c
@@ -181,41 +181,43 @@ static bool icl_tc_phy_set_safe_mode(struct intel_digital_port *dig_port,
  * will require a lot of coordination with user space and thorough testing for
  * the extra possible cases.
  */
-static bool icl_tc_phy_connect(struct intel_digital_port *dig_port)
+static void icl_tc_phy_connect(struct intel_digital_port *dig_port)
 {
-       u32 live_status_mask;
-
-       if (dig_port->tc_mode != TC_PORT_LEGACY &&
-           dig_port->tc_mode != TC_PORT_DP_ALT)
-               return true;
-
        if (!icl_tc_phy_status_complete(dig_port)) {
                DRM_DEBUG_KMS("Port %s: PHY not ready\n",
                              dig_port->tc_port_name);
-               WARN_ON(dig_port->tc_legacy_port);
-               return false;
+               goto out_set_tbt_alt_mode;
        }
 
-       if (!icl_tc_phy_set_safe_mode(dig_port, false))
-               return false;
+       if (!icl_tc_phy_set_safe_mode(dig_port, false) &&
+           !WARN_ON(dig_port->tc_legacy_port))
+               goto out_set_tbt_alt_mode;
 
-       if (dig_port->tc_mode == TC_PORT_LEGACY)
-               return true;
+       if (dig_port->tc_legacy_port) {
+               WARN_ON(intel_tc_port_fia_max_lane_count(dig_port) != 4);
+               dig_port->tc_mode = TC_PORT_LEGACY;
 
-       live_status_mask = tc_port_live_status_mask(dig_port);
+               return;
+       }
 
        /*
         * Now we have to re-check the live state, in case the port recently
         * became disconnected. Not necessary for legacy mode.
         */
-       if (!(live_status_mask & BIT(TC_PORT_DP_ALT))) {
+       if (!(tc_port_live_status_mask(dig_port) & BIT(TC_PORT_DP_ALT))) {
                DRM_DEBUG_KMS("Port %s: PHY sudden disconnect\n",
                              dig_port->tc_port_name);
-               icl_tc_phy_disconnect(dig_port);
-               return false;
+               goto out_set_safe_mode;
        }
 
-       return true;
+       dig_port->tc_mode = TC_PORT_DP_ALT;
+
+       return;
+
+out_set_safe_mode:
+       icl_tc_phy_set_safe_mode(dig_port, true);
+out_set_tbt_alt_mode:
+       dig_port->tc_mode = TC_PORT_TBT_ALT;
 }
 
 /*
@@ -236,27 +238,37 @@ void icl_tc_phy_disconnect(struct intel_digital_port *dig_port)
        default:
                MISSING_CASE(dig_port->tc_mode);
        }
+}
 
-       DRM_DEBUG_KMS("Port %s: mode %s disconnected\n",
-                     dig_port->tc_port_name,
-                     tc_port_mode_name(dig_port->tc_mode));
+static enum tc_port_mode
+intel_tc_port_get_target_mode(struct intel_digital_port *dig_port)
+{
+       u32 live_status_mask = tc_port_live_status_mask(dig_port);
+
+       if (live_status_mask)
+               return fls(live_status_mask) - 1;
+
+       return icl_tc_phy_status_complete(dig_port) &&
+              dig_port->tc_legacy_port ? TC_PORT_LEGACY :
+                                         TC_PORT_TBT_ALT;
 }
 
-static void icl_update_tc_port_type(struct drm_i915_private *dev_priv,
-                                   struct intel_digital_port *intel_dig_port,
-                                   u32 live_status_mask)
+static void intel_tc_port_reset_mode(struct intel_digital_port *dig_port)
 {
-       enum tc_port_mode old_mode = intel_dig_port->tc_mode;
+       enum tc_port_mode old_tc_mode = dig_port->tc_mode;
 
-       if (!live_status_mask)
-               return;
+       icl_tc_phy_disconnect(dig_port);
+       icl_tc_phy_connect(dig_port);
 
-       intel_dig_port->tc_mode = fls(live_status_mask) - 1;
+       DRM_DEBUG_KMS("Port %s: TC port mode reset (%s -> %s)\n",
+                     dig_port->tc_port_name,
+                     tc_port_mode_name(old_tc_mode),
+                     tc_port_mode_name(dig_port->tc_mode));
+}
 
-       if (old_mode != intel_dig_port->tc_mode)
-               DRM_DEBUG_KMS("Port %s: port has mode %s\n",
-                             intel_dig_port->tc_port_name,
-                             tc_port_mode_name(intel_dig_port->tc_mode));
+static bool intel_tc_port_needs_reset(struct intel_digital_port *dig_port)
+{
+       return intel_tc_port_get_target_mode(dig_port) != dig_port->tc_mode;
 }
 
 /*
@@ -271,24 +283,10 @@ static void icl_update_tc_port_type(struct drm_i915_private *dev_priv,
  */
 bool intel_tc_port_connected(struct intel_digital_port *dig_port)
 {
-       struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
-       u32 live_status_mask = tc_port_live_status_mask(dig_port);
-
-       /*
-        * The spec says we shouldn't be using the ISR bits for detecting
-        * between TC and TBT. We should use DFLEXDPSP.
-        */
-       if (!live_status_mask && !dig_port->tc_legacy_port) {
-               icl_tc_phy_disconnect(dig_port);
-
-               return false;
-       }
-
-       icl_update_tc_port_type(dev_priv, dig_port, live_status_mask);
-       if (!icl_tc_phy_connect(dig_port))
-               return false;
+       if (intel_tc_port_needs_reset(dig_port))
+               intel_tc_port_reset_mode(dig_port);
 
-       return true;
+       return tc_port_live_status_mask(dig_port) & BIT(dig_port->tc_mode);
 }
 
 void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy)