drm/i915/tc: Call TypeC port flush_work/cleanup without modeset locks held

Call the TypeC port flush_work and cleanup handlers without the modeset
locks held. These don't require the locks, as the work takes - as it
should be able to at any point in time - any locks it needs and by the
time cleanup is called and after cleanup returns the encoder is not in
use.

This is required by the next patch canceling a TypeC port work
synchronously during encoder suspend and shutdown, where the work can
take modeset locks as well, hence the canceling must be done without
holding the locks.

I also considered moving the modeset locking down to each encoder
suspend()/shutdown() hook instead, however locking the full modeset
state for each encoder separately would be odd, and the bigger change -
affecting all encoders - is beyond the scope of this patchset.

v2:
- Add a TODO: comment to remove modeset locks if no encoder depends
  on this. (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230512195513.2699-1-imre.deak@intel.com

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -4615,31 +4615,27 @@ static bool intel_ddi_is_tc(struct drm_i915_private *i915, enum port port)
 
 static void intel_ddi_encoder_suspend(struct intel_encoder *encoder)
 {
-	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
-	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
-	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
-	enum phy phy = intel_port_to_phy(i915, encoder->port);
-
 	intel_dp_encoder_suspend(encoder);
+}
 
-	if (!intel_phy_is_tc(i915, phy))
-		return;
+static void intel_ddi_tc_encoder_suspend_complete(struct intel_encoder *encoder)
+{
+	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
 
 	intel_tc_port_flush_work(dig_port);
 }
 
 static void intel_ddi_encoder_shutdown(struct intel_encoder *encoder)
 {
-	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
-	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
-	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
-	enum phy phy = intel_port_to_phy(i915, encoder->port);
-
 	intel_dp_encoder_shutdown(encoder);
 	intel_hdmi_encoder_shutdown(encoder);
+}
 
-	if (!intel_phy_is_tc(i915, phy))
-		return;
+static void intel_ddi_tc_encoder_shutdown_complete(struct intel_encoder *encoder)
+{
+	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
 
 	intel_tc_port_cleanup(dig_port);
 }
@@ -4906,6 +4902,9 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 				    is_legacy ? "legacy" : "non-legacy");
 		}
 
+		encoder->suspend_complete = intel_ddi_tc_encoder_suspend_complete;
+		encoder->shutdown_complete = intel_ddi_tc_encoder_shutdown_complete;
+
 		if (intel_tc_port_init(dig_port, is_legacy) < 0)
 			goto err;
 	}

drivers/gpu/drm/i915/display/intel_display_types.h

@@ -233,13 +233,25 @@ struct intel_encoder {
 	 * Called during system suspend after all pending requests for the
 	 * encoder are flushed (for example for DP AUX transactions) and
 	 * device interrupts are disabled.
+	 * All modeset locks are held while the hook is called.
 	 */
 	void (*suspend)(struct intel_encoder *);
+	/*
+	 * Called without the modeset locks held after the suspend() hook for
+	 * all encoders have been called.
+	 */
+	void (*suspend_complete)(struct intel_encoder *encoder);
 	/*
 	 * Called during system reboot/shutdown after all the
 	 * encoders have been disabled and suspended.
+	 * All modeset locks are held while the hook is called.
 	 */
 	void (*shutdown)(struct intel_encoder *encoder);
+	/*
+	 * Called without the modeset locks held after the shutdown() hook for
+	 * all encoders have been called.
+	 */
+	void (*shutdown_complete)(struct intel_encoder *encoder);
 	/*
 	 * Enable/disable the clock to the port.
 	 */

drivers/gpu/drm/i915/i915_driver.c

@@ -957,11 +957,19 @@ static void intel_suspend_encoders(struct drm_i915_private *dev_priv)
 	if (!HAS_DISPLAY(dev_priv))
 		return;
 
+	/*
+	 * TODO: check and remove holding the modeset locks if none of
+	 * the encoders depends on this.
+	 */
 	drm_modeset_lock_all(&dev_priv->drm);
 	for_each_intel_encoder(&dev_priv->drm, encoder)
 		if (encoder->suspend)
 			encoder->suspend(encoder);
 	drm_modeset_unlock_all(&dev_priv->drm);
+
+	for_each_intel_encoder(&dev_priv->drm, encoder)
+		if (encoder->suspend_complete)
+			encoder->suspend_complete(encoder);
 }
 
 static void intel_shutdown_encoders(struct drm_i915_private *dev_priv)
@@ -971,11 +979,19 @@ static void intel_shutdown_encoders(struct drm_i915_private *dev_priv)
 	if (!HAS_DISPLAY(dev_priv))
 		return;
 
+	/*
+	 * TODO: check and remove holding the modeset locks if none of
+	 * the encoders depends on this.
+	 */
 	drm_modeset_lock_all(&dev_priv->drm);
 	for_each_intel_encoder(&dev_priv->drm, encoder)
 		if (encoder->shutdown)
 			encoder->shutdown(encoder);
 	drm_modeset_unlock_all(&dev_priv->drm);
+
+	for_each_intel_encoder(&dev_priv->drm, encoder)
+		if (encoder->shutdown_complete)
+			encoder->shutdown_complete(encoder);
 }
 
 void i915_driver_shutdown(struct drm_i915_private *i915)