drm/i915: Disable PSR around cdclk changes

AUX logic is often clocked from cdclk. Disable PSR to make sure
there are no hw initiated AUX transactions in flight while we
change the cdclk frequency.

Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210608085415.515342-2-gwan-gyeong.mun@intel.com

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

@@ -28,6 +28,7 @@
 #include "intel_cdclk.h"
 #include "intel_de.h"
 #include "intel_display_types.h"
+#include "intel_psr.h"
 #include "intel_sideband.h"
 
 /**
@@ -1908,6 +1909,12 @@ static void intel_set_cdclk(struct drm_i915_private *dev_priv,
 
 	intel_dump_cdclk_config(cdclk_config, "Changing CDCLK to");
 
+	for_each_intel_encoder_with_psr(&dev_priv->drm, encoder) {
+		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
+
+		intel_psr_pause(intel_dp);
+	}
+
 	/*
 	 * Lock aux/gmbus while we change cdclk in case those
 	 * functions use cdclk. Not all platforms/ports do,
@@ -1930,6 +1937,12 @@ static void intel_set_cdclk(struct drm_i915_private *dev_priv,
 	}
 	mutex_unlock(&dev_priv->gmbus_mutex);
 
+	for_each_intel_encoder_with_psr(&dev_priv->drm, encoder) {
+		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
+
+		intel_psr_resume(intel_dp);
+	}
+
 	if (drm_WARN(&dev_priv->drm,
 		     intel_cdclk_changed(&dev_priv->cdclk.hw, cdclk_config),
 		     "cdclk state doesn't match!\n")) {