[PATCH 2/6] drm/i915/pps: Hold a TypeC link reference for PPS VDD

[Imre Deak <imre.deak@intel.com>]

On TypeC ports, the AUX power domain reference held for PPS VDD requires
the TypeC mode to remain unchanged. Hold a TypeC link reference for the
lifetime of the PPS VDD power reference.

This prepares for an upcoming change that will use the TypeC port type
for eDP on TypeC ports. Allow the additional PPS link reference when
sanitizing the TypeC mode.

CC: stable@vger.kernel.org # 6.14+
Signed-off-by: Imre Deak <imre.deak@intel.com>
---
 drivers/gpu/drm/i915/display/intel_pps.c | 14 ++++++++++++++
 drivers/gpu/drm/i915/display/intel_tc.c  |  9 +++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_pps.c b/drivers/gpu/drm/i915/display/intel_pps.c
index d4c98b150fa2b..8f1bfe4340971 100644
--- a/drivers/gpu/drm/i915/display/intel_pps.c
+++ b/drivers/gpu/drm/i915/display/intel_pps.c
@@ -23,6 +23,7 @@
 #include "intel_pps.h"
 #include "intel_pps_regs.h"
 #include "intel_quirks.h"
+#include "intel_tc.h"
 
 static void vlv_steal_power_sequencer(struct intel_display *display,
 				      enum pipe pipe);
@@ -758,6 +759,9 @@ bool intel_pps_vdd_on_unlocked(struct intel_dp *intel_dp)
 	if (edp_have_panel_vdd(intel_dp))
 		return need_to_disable;
 
+	if (intel_encoder_is_tc(&dig_port->base))
+		intel_tc_port_get_link(dig_port, 1);
+
 	drm_WARN_ON(display->drm, intel_dp->pps.vdd_wakeref);
 	intel_dp->pps.vdd_wakeref = intel_display_power_get(display,
 							    intel_aux_power_domain(dig_port));
@@ -864,6 +868,9 @@ static void intel_pps_vdd_off_sync_unlocked(struct intel_dp *intel_dp)
 	intel_display_power_put(display,
 				intel_aux_power_domain(dig_port),
 				fetch_and_zero(&intel_dp->pps.vdd_wakeref));
+
+	if (intel_encoder_is_tc(&dig_port->base))
+		intel_tc_port_put_link(dig_port);
 }
 
 void intel_pps_vdd_off_sync(struct intel_dp *intel_dp)
@@ -1066,6 +1073,9 @@ void intel_pps_off_unlocked(struct intel_dp *intel_dp)
 	intel_display_power_put(display,
 				intel_aux_power_domain(dig_port),
 				fetch_and_zero(&intel_dp->pps.vdd_wakeref));
+
+	if (intel_encoder_is_tc(&dig_port->base))
+		intel_tc_port_put_link(dig_port);
 }
 
 void intel_pps_off(struct intel_dp *intel_dp)
@@ -1334,6 +1344,10 @@ static void pps_vdd_init(struct intel_dp *intel_dp)
 		    "[ENCODER:%d:%s] %s VDD left on by BIOS, adjusting state tracking\n",
 		    dig_port->base.base.base.id, dig_port->base.base.name,
 		    pps_name(intel_dp));
+
+	if (intel_encoder_is_tc(&dig_port->base))
+		intel_tc_port_get_link(dig_port, 1);
+
 	drm_WARN_ON(display->drm, intel_dp->pps.vdd_wakeref);
 	intel_dp->pps.vdd_wakeref = intel_display_power_get(display,
 							    intel_aux_power_domain(dig_port));
diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
index f2d86b29c4154..f878494bcb388 100644
--- a/drivers/gpu/drm/i915/display/intel_tc.c
+++ b/drivers/gpu/drm/i915/display/intel_tc.c
@@ -1669,7 +1669,7 @@ void intel_tc_port_sanitize_mode(struct intel_digital_port *dig_port,
 
 	mutex_lock(&tc->lock);
 
-	drm_WARN_ON(display->drm, tc->link_refcount != 1);
+	drm_WARN_ON(display->drm, tc->link_refcount < 1);
 	if (!tc_port_has_active_streams(tc, crtc_state)) {
 		/*
 		 * TBT-alt is the default mode in any case the PHY ownership is not
@@ -1683,7 +1683,12 @@ void intel_tc_port_sanitize_mode(struct intel_digital_port *dig_port,
 				    "Port %s: PHY left in %s mode on disabled port, disconnecting it\n",
 				    tc->port_name,
 				    tc_port_mode_name(tc->init_mode));
-		tc_phy_disconnect(tc);
+		/*
+		 * A link reference taken during a preceding (eDP) connector initialization will be
+		 * dropped later, also disconnecting the PHY.
+		 */
+		if (tc->link_refcount == 1)
+			tc_phy_disconnect(tc);
 		__intel_tc_port_put_link(tc);
 	}
 
-- 
2.49.1