drm/i915: Replace the VLV/CHV eDP reboot notifier with the .shutdown() hook

Currently VLV/CHV use a reboot notifier to make sure the panel
power cycle delay isn't violated across a system reboot. Replace
that with the new encoder .shutdown() hook.

And let's also stop overriding the power cycle delay with the
max value. No idea why the current code does that. The already
programmed delay should be correct.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201001151640.14590-3-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

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

@@ -1334,8 +1334,6 @@ struct intel_dp {
 	unsigned long last_backlight_off;
 	ktime_t panel_power_off_time;
 
-	struct notifier_block edp_notifier;
-
 	/*
 	 * Pipe whose power sequencer is currently locked into
 	 * this port. Only relevant on VLV/CHV.

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

@@ -28,7 +28,6 @@
 #include <linux/export.h>
 #include <linux/i2c.h>
 #include <linux/notifier.h>
-#include <linux/reboot.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 
@@ -1200,41 +1199,6 @@ _pp_stat_reg(struct intel_dp *intel_dp)
 	return regs.pp_stat;
 }
 
-/* Reboot notifier handler to shutdown panel power to guarantee T12 timing
-   This function only applicable when panel PM state is not to be tracked */
-static int edp_notify_handler(struct notifier_block *this, unsigned long code,
-			      void *unused)
-{
-	struct intel_dp *intel_dp = container_of(this, typeof(* intel_dp),
-						 edp_notifier);
-	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
-	intel_wakeref_t wakeref;
-
-	if (!intel_dp_is_edp(intel_dp) || code != SYS_RESTART)
-		return 0;
-
-	with_pps_lock(intel_dp, wakeref) {
-		if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
-			enum pipe pipe = vlv_power_sequencer_pipe(intel_dp);
-			i915_reg_t pp_ctrl_reg, pp_div_reg;
-			u32 pp_div;
-
-			pp_ctrl_reg = PP_CONTROL(pipe);
-			pp_div_reg  = PP_DIVISOR(pipe);
-			pp_div = intel_de_read(dev_priv, pp_div_reg);
-			pp_div &= PP_REFERENCE_DIVIDER_MASK;
-
-			/* 0x1F write to PP_DIV_REG sets max cycle delay */
-			intel_de_write(dev_priv, pp_div_reg, pp_div | 0x1F);
-			intel_de_write(dev_priv, pp_ctrl_reg,
-				       PANEL_UNLOCK_REGS);
-			msleep(intel_dp->panel_power_cycle_delay);
-		}
-	}
-
-	return 0;
-}
-
 static bool edp_have_panel_power(struct intel_dp *intel_dp)
 {
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
@@ -6758,11 +6722,6 @@ void intel_dp_encoder_flush_work(struct drm_encoder *encoder)
 		 */
 		with_pps_lock(intel_dp, wakeref)
 			edp_panel_vdd_off_sync(intel_dp);
-
-		if (intel_dp->edp_notifier.notifier_call) {
-			unregister_reboot_notifier(&intel_dp->edp_notifier);
-			intel_dp->edp_notifier.notifier_call = NULL;
-		}
 	}
 
 	intel_dp_aux_fini(intel_dp);
@@ -6793,6 +6752,18 @@ void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder)
 		edp_panel_vdd_off_sync(intel_dp);
 }
 
+static void intel_dp_encoder_shutdown(struct intel_encoder *intel_encoder)
+{
+	struct intel_dp *intel_dp = enc_to_intel_dp(intel_encoder);
+	intel_wakeref_t wakeref;
+
+	if (!intel_dp_is_edp(intel_dp))
+		return;
+
+	with_pps_lock(intel_dp, wakeref)
+		wait_panel_power_cycle(intel_dp);
+}
+
 static void intel_edp_panel_vdd_sanitize(struct intel_dp *intel_dp)
 {
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
@@ -7905,9 +7876,6 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
 	mutex_unlock(&dev->mode_config.mutex);
 
 	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
-		intel_dp->edp_notifier.notifier_call = edp_notify_handler;
-		register_reboot_notifier(&intel_dp->edp_notifier);
-
 		/*
 		 * Figure out the current pipe for the initial backlight setup.
 		 * If the current pipe isn't valid, try the PPS pipe, and if that
@@ -8130,6 +8098,8 @@ bool intel_dp_init(struct drm_i915_private *dev_priv,
 	intel_encoder->initial_fastset_check = intel_dp_initial_fastset_check;
 	intel_encoder->update_pipe = intel_panel_update_backlight;
 	intel_encoder->suspend = intel_dp_encoder_suspend;
+	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
+		intel_encoder->shutdown = intel_dp_encoder_shutdown;
 	if (IS_CHERRYVIEW(dev_priv)) {
 		intel_encoder->pre_pll_enable = chv_dp_pre_pll_enable;
 		intel_encoder->pre_enable = chv_pre_enable_dp;