drm/i915/tc: Fix TypeC PHY connect/disconnect logic on ADL-P

So far TC-cold was blocked only for the duration of TypeC mode resets.
The DP-alt and legacy modes require TC-cold to be blocked also whenever
the port is in use (AUX transfers, enable modeset), and this was ensured
by the held PHY ownership flag. On ADL-P this doesn't work, since the
PHY ownership flag is in a register backed by the PW#2 power well.
Whenever this power well is disabled the ownership flag is cleared by
the HW under the driver.

The only way to cleanly release and re-acquire the PHY ownership flag
and also allow for power saving (by disabling the display power wells
and reaching DC5/6 states) is to hold the TC-cold blocking power domains
while the PHY is connected and disconnect/reconnect the PHY on-demand
around AUX transfers and modeset enable/disables. Let's do that,
disconnecting a PHY with a 1 sec delay after it becomes idle. For
consistency do this on all platforms and TypeC modes.

v2: Add tc_mode!=disconnected and phy_is_owned asserts to
    __intel_tc_port_lock().

Cc: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210929132833.2253961-6-imre.deak@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 0fe77854b4557178b9441ba308d48640402a5c7d..51d07e9af9f3d77813041369dd76803631dc3da7 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -4017,8 +4017,11 @@ static void intel_ddi_encoder_destroy(struct drm_encoder *encoder)
 {
        struct drm_i915_private *i915 = to_i915(encoder->dev);
        struct intel_digital_port *dig_port = enc_to_dig_port(to_intel_encoder(encoder));
+       enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
 
        intel_dp_encoder_flush_work(encoder);
+       if (intel_phy_is_tc(i915, phy))
+               intel_tc_port_flush_work(dig_port);
        intel_display_power_flush_work(i915);
 
        drm_encoder_cleanup(encoder);
@@ -4443,7 +4446,7 @@ static void intel_ddi_encoder_suspend(struct intel_encoder *encoder)
        if (!intel_phy_is_tc(i915, phy))
                return;
 
-       intel_tc_port_disconnect_phy(dig_port);
+       intel_tc_port_flush_work(dig_port);
 }
 
 static void intel_ddi_encoder_shutdown(struct intel_encoder *encoder)
@@ -4458,7 +4461,7 @@ static void intel_ddi_encoder_shutdown(struct intel_encoder *encoder)
        if (!intel_phy_is_tc(i915, phy))
                return;
 
-       intel_tc_port_disconnect_phy(dig_port);
+       intel_tc_port_flush_work(dig_port);
 }
 
 #define port_tc_name(port) ((port) - PORT_TC1 + '1')

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index f41fdc376a5160ffbd2be20411443fa8037aefb3..632391197937397c4c3ebec491034ec128d746a1 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1666,6 +1666,7 @@ struct intel_digital_port {
        struct mutex tc_lock;   /* protects the TypeC port mode */
        intel_wakeref_t tc_lock_wakeref;
        enum intel_display_power_domain tc_lock_power_domain;
+       struct delayed_work tc_disconnect_phy_work;
        int tc_link_refcount;
        bool tc_legacy_port:1;
        char tc_port_name[8];

diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
index 9367770de5d7926ceaf45bde27f127525ed74391..66cb321a4488d2baf63c16feedcd0cd043d635b1 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_tc.c
+++ b/drivers/gpu/drm/i915/display/intel_tc.c
@@ -666,6 +666,13 @@ static void intel_tc_port_update_mode(struct intel_digital_port *dig_port,
 
        intel_tc_port_reset_mode(dig_port, required_lanes, force_disconnect);
 
+       /* Get power domain matching the new mode after reset. */
+       tc_cold_unblock(dig_port, dig_port->tc_lock_power_domain,
+                       fetch_and_zero(&dig_port->tc_lock_wakeref));
+       if (dig_port->tc_mode != TC_PORT_DISCONNECTED)
+               dig_port->tc_lock_wakeref = tc_cold_block(dig_port,
+                                                         &dig_port->tc_lock_power_domain);
+
        tc_cold_unblock(dig_port, domain, wref);
 }
 
@@ -693,6 +700,7 @@ void intel_tc_port_sanitize(struct intel_digital_port *dig_port)
                active_links = to_intel_crtc(encoder->base.crtc)->active;
 
        drm_WARN_ON(&i915->drm, dig_port->tc_mode != TC_PORT_DISCONNECTED);
+       drm_WARN_ON(&i915->drm, dig_port->tc_lock_wakeref);
        if (active_links) {
                enum intel_display_power_domain domain;
                intel_wakeref_t tc_cold_wref = tc_cold_block(dig_port, &domain);
@@ -705,6 +713,9 @@ void intel_tc_port_sanitize(struct intel_digital_port *dig_port)
                                    dig_port->tc_port_name, active_links);
                intel_tc_port_link_init_refcount(dig_port, active_links);
 
+               dig_port->tc_lock_wakeref = tc_cold_block(dig_port,
+                                                         &dig_port->tc_lock_power_domain);
+
                tc_cold_unblock(dig_port, domain, tc_cold_wref);
        }
 
@@ -745,56 +756,67 @@ bool intel_tc_port_connected(struct intel_encoder *encoder)
 }
 
 static void __intel_tc_port_lock(struct intel_digital_port *dig_port,
-                                int required_lanes, bool force_disconnect)
+                                int required_lanes)
 {
        struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
-       intel_wakeref_t wakeref;
-
-       wakeref = intel_display_power_get(i915, POWER_DOMAIN_DISPLAY_CORE);
 
        mutex_lock(&dig_port->tc_lock);
 
+       cancel_delayed_work(&dig_port->tc_disconnect_phy_work);
 
        if (!dig_port->tc_link_refcount)
                intel_tc_port_update_mode(dig_port, required_lanes,
-                                         force_disconnect);
+                                         false);
 
-       drm_WARN_ON(&i915->drm, dig_port->tc_lock_wakeref);
-       dig_port->tc_lock_wakeref = wakeref;
+       drm_WARN_ON(&i915->drm, dig_port->tc_mode == TC_PORT_DISCONNECTED);
+       drm_WARN_ON(&i915->drm, dig_port->tc_mode != TC_PORT_TBT_ALT &&
+                               !tc_phy_is_owned(dig_port));
 }
 
 void intel_tc_port_lock(struct intel_digital_port *dig_port)
 {
-       __intel_tc_port_lock(dig_port, 1, false);
+       __intel_tc_port_lock(dig_port, 1);
 }
 
-void intel_tc_port_unlock(struct intel_digital_port *dig_port)
+/**
+ * intel_tc_port_disconnect_phy_work: disconnect TypeC PHY from display port
+ * @dig_port: digital port
+ *
+ * Disconnect the given digital port from its TypeC PHY (handing back the
+ * control of the PHY to the TypeC subsystem). This will happen in a delayed
+ * manner after each aux transactions and modeset disables.
+ */
+static void intel_tc_port_disconnect_phy_work(struct work_struct *work)
 {
-       struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
-       intel_wakeref_t wakeref = fetch_and_zero(&dig_port->tc_lock_wakeref);
+       struct intel_digital_port *dig_port =
+               container_of(work, struct intel_digital_port, tc_disconnect_phy_work.work);
 
-       mutex_unlock(&dig_port->tc_lock);
+       mutex_lock(&dig_port->tc_lock);
 
-       intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE,
-                                     wakeref);
+       if (!dig_port->tc_link_refcount)
+               intel_tc_port_update_mode(dig_port, 1, true);
+
+       mutex_unlock(&dig_port->tc_lock);
 }
 
 /**
- * intel_tc_port_disconnect_phy: disconnect TypeC PHY from display port
+ * intel_tc_port_flush_work: flush the work disconnecting the PHY
  * @dig_port: digital port
  *
- * Disconnect the given digital port from its TypeC PHY (handing back the
- * control of the PHY to the TypeC subsystem). The only purpose of this
- * function is to force the disconnect even with a TypeC display output still
- * plugged to the TypeC connector, which is required by the TypeC firmwares
- * during system suspend and shutdown. Otherwise - during the unplug event
- * handling - the PHY ownership is released automatically by
- * intel_tc_port_reset_mode(), when calling this function is not required.
+ * Flush the delayed work disconnecting an idle PHY.
  */
-void intel_tc_port_disconnect_phy(struct intel_digital_port *dig_port)
+void intel_tc_port_flush_work(struct intel_digital_port *dig_port)
 {
-       __intel_tc_port_lock(dig_port, 1, true);
-       intel_tc_port_unlock(dig_port);
+       flush_delayed_work(&dig_port->tc_disconnect_phy_work);
+}
+
+void intel_tc_port_unlock(struct intel_digital_port *dig_port)
+{
+       if (!dig_port->tc_link_refcount && dig_port->tc_mode != TC_PORT_DISCONNECTED)
+               queue_delayed_work(system_unbound_wq, &dig_port->tc_disconnect_phy_work,
+                                  msecs_to_jiffies(1000));
+
+       mutex_unlock(&dig_port->tc_lock);
 }
 
 bool intel_tc_port_ref_held(struct intel_digital_port *dig_port)
@@ -806,16 +828,16 @@ bool intel_tc_port_ref_held(struct intel_digital_port *dig_port)
 void intel_tc_port_get_link(struct intel_digital_port *dig_port,
                            int required_lanes)
 {
-       __intel_tc_port_lock(dig_port, required_lanes, false);
+       __intel_tc_port_lock(dig_port, required_lanes);
        dig_port->tc_link_refcount++;
        intel_tc_port_unlock(dig_port);
 }
 
 void intel_tc_port_put_link(struct intel_digital_port *dig_port)
 {
-       mutex_lock(&dig_port->tc_lock);
-       dig_port->tc_link_refcount--;
-       mutex_unlock(&dig_port->tc_lock);
+       intel_tc_port_lock(dig_port);
+       --dig_port->tc_link_refcount;
+       intel_tc_port_unlock(dig_port);
 }
 
 static bool
@@ -871,6 +893,7 @@ void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy)
                 "%c/TC#%d", port_name(port), tc_port + 1);
 
        mutex_init(&dig_port->tc_lock);
+       INIT_DELAYED_WORK(&dig_port->tc_disconnect_phy_work, intel_tc_port_disconnect_phy_work);
        dig_port->tc_legacy_port = is_legacy;
        dig_port->tc_mode = TC_PORT_DISCONNECTED;
        dig_port->tc_link_refcount = 0;

diff --git a/drivers/gpu/drm/i915/display/intel_tc.h b/drivers/gpu/drm/i915/display/intel_tc.h
index 0fdcddb4fc87010a70b5e1eaa7b60b488e66c4ce..6b47b29f551c937dfa19a1fd6a885385774f7136 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_tc.h
+++ b/drivers/gpu/drm/i915/display/intel_tc.h
@@ -17,7 +17,6 @@ bool intel_tc_port_in_dp_alt_mode(struct intel_digital_port *dig_port);
 bool intel_tc_port_in_legacy_mode(struct intel_digital_port *dig_port);
 
 bool intel_tc_port_connected(struct intel_encoder *encoder);
-void intel_tc_port_disconnect_phy(struct intel_digital_port *dig_port);
 
 u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port);
 u32 intel_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_port);
@@ -28,6 +27,7 @@ void intel_tc_port_set_fia_lane_count(struct intel_digital_port *dig_port,
 void intel_tc_port_sanitize(struct intel_digital_port *dig_port);
 void intel_tc_port_lock(struct intel_digital_port *dig_port);
 void intel_tc_port_unlock(struct intel_digital_port *dig_port);
+void intel_tc_port_flush_work(struct intel_digital_port *dig_port);
 void intel_tc_port_get_link(struct intel_digital_port *dig_port,
                            int required_lanes);
 void intel_tc_port_put_link(struct intel_digital_port *dig_port);