[SRU,B/OEM-B] drm/i915: Force 2*96 MHz cdclk on glk/cnl when audio power is enabled

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 706a2bc5f37d..eaba810a928e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2358,6 +2358,8 @@  struct drm_i915_private {
 		struct intel_cdclk_state actual;
 		/* The current hardware cdclk state */
 		struct intel_cdclk_state hw;
+
+		int force_min_cdclk;
 	} cdclk;
 
 	/**
@@ -2478,6 +2480,7 @@  struct drm_i915_private {
 	 *
 	 */
 	struct mutex av_mutex;
+	int audio_power_refcount;
 
 	struct {
 		struct list_head list;
diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index d1a8c0fa2d38..0d9c65f40116 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -688,13 +688,70 @@  void intel_init_audio_hooks(struct drm_i915_private *dev_priv)
 	}
 }
 
+static void glk_force_audio_cdclk(struct drm_i915_private *dev_priv,
+				  bool enable)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_state *state;
+	int ret;
+
+	drm_modeset_acquire_init(&ctx, 0);
+	state = drm_atomic_state_alloc(&dev_priv->drm);
+	if (WARN_ON(!state))
+		return;
+
+	state->acquire_ctx = &ctx;
+
+ retry:
+	to_intel_atomic_state(state)->cdclk.force_min_cdclk_changed = true;
+	to_intel_atomic_state(state)->cdclk.force_min_cdclk =
+		enable ? 2 * 96000 : 0;
+
+	/*
+	 * Protects dev_priv->cdclk.force_min_cdclk
+	 * Need to lock this here in case we have no active pipes
+	 * and thus wouldn't lock it during the commit otherwise.
+	 */
+	ret = drm_modeset_lock(&dev_priv->drm.mode_config.connection_mutex,
+			       &ctx);
+	if (!ret)
+		ret = drm_atomic_commit(state);
+
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		drm_modeset_backoff(&ctx);
+		goto retry;
+	}
+
+	WARN_ON(ret);
+
+	drm_atomic_state_put(state);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+
 static void i915_audio_component_get_power(struct device *kdev)
 {
+	struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
 	intel_display_power_get(kdev_to_i915(kdev), POWER_DOMAIN_AUDIO);
+
+	/* Force CDCLK to 2*BCLK as long as we need audio to be powered. */
+	if (dev_priv->audio_power_refcount++ == 0)
+		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
+			glk_force_audio_cdclk(dev_priv, true);
+
 }
 
 static void i915_audio_component_put_power(struct device *kdev)
 {
+	struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
+
+	/* Stop forcing CDCLK to 2*BCLK if no need for audio to be powered. */
+	if (--dev_priv->audio_power_refcount == 0)
+		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
+			glk_force_audio_cdclk(dev_priv, false);
+
 	intel_display_power_put(kdev_to_i915(kdev), POWER_DOMAIN_AUDIO);
 }
 
diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
index 2f678aff46f8..cb23023d9da1 100644
--- a/drivers/gpu/drm/i915/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/intel_cdclk.c
@@ -1819,19 +1819,8 @@  int intel_crtc_compute_min_cdclk(const struct intel_crtc_state *crtc_state)
 	/*
 	 * According to BSpec, "The CD clock frequency must be at least twice
 	 * the frequency of the Azalia BCLK." and BCLK is 96 MHz by default.
-	 *
-	 * FIXME: Check the actual, not default, BCLK being used.
-	 *
-	 * FIXME: This does not depend on ->has_audio because the higher CDCLK
-	 * is required for audio probe, also when there are no audio capable
-	 * displays connected at probe time. This leads to unnecessarily high
-	 * CDCLK when audio is not required.
-	 *
-	 * FIXME: This limit is only applied when there are displays connected
-	 * at probe time. If we probe without displays, we'll still end up using
-	 * the platform minimum CDCLK, failing audio probe.
 	 */
-	if (INTEL_GEN(dev_priv) >= 9)
+	if (crtc_state->has_audio && INTEL_GEN(dev_priv) >= 9)
 		min_cdclk = max(2 * 96000, min_cdclk);
 
 	if (min_cdclk > dev_priv->max_cdclk_freq) {
@@ -1863,7 +1852,7 @@  static int intel_compute_min_cdclk(struct drm_atomic_state *state)
 		intel_state->min_cdclk[i] = min_cdclk;
 	}
 
-	min_cdclk = 0;
+	min_cdclk = intel_state->cdclk.force_min_cdclk;
 	for_each_pipe(dev_priv, pipe)
 		min_cdclk = max(intel_state->min_cdclk[pipe], min_cdclk);
 
@@ -1885,7 +1874,8 @@  static int vlv_modeset_calc_cdclk(struct drm_atomic_state *state)
 	intel_state->cdclk.logical.cdclk = cdclk;
 
 	if (!intel_state->active_crtcs) {
-		cdclk = vlv_calc_cdclk(dev_priv, 0);
+		cdclk = vlv_calc_cdclk(dev_priv,
+				       intel_state->cdclk.force_min_cdclk);
 
 		intel_state->cdclk.actual.cdclk = cdclk;
 	} else {
@@ -1914,7 +1904,7 @@  static int bdw_modeset_calc_cdclk(struct drm_atomic_state *state)
 	intel_state->cdclk.logical.cdclk = cdclk;
 
 	if (!intel_state->active_crtcs) {
-		cdclk = bdw_calc_cdclk(0);
+		cdclk = bdw_calc_cdclk(intel_state->cdclk.force_min_cdclk);
 
 		intel_state->cdclk.actual.cdclk = cdclk;
 	} else {
@@ -1982,7 +1972,7 @@  static int skl_modeset_calc_cdclk(struct drm_atomic_state *state)
 	intel_state->cdclk.logical.cdclk = cdclk;
 
 	if (!intel_state->active_crtcs) {
-		cdclk = skl_calc_cdclk(0, vco);
+		cdclk = skl_calc_cdclk(intel_state->cdclk.force_min_cdclk, vco);
 
 		intel_state->cdclk.actual.vco = vco;
 		intel_state->cdclk.actual.cdclk = cdclk;
@@ -2017,10 +2007,10 @@  static int bxt_modeset_calc_cdclk(struct drm_atomic_state *state)
 
 	if (!intel_state->active_crtcs) {
 		if (IS_GEMINILAKE(dev_priv)) {
-			cdclk = glk_calc_cdclk(0);
+			cdclk = glk_calc_cdclk(intel_state->cdclk.force_min_cdclk);
 			vco = glk_de_pll_vco(dev_priv, cdclk);
 		} else {
-			cdclk = bxt_calc_cdclk(0);
+			cdclk = bxt_calc_cdclk(intel_state->cdclk.force_min_cdclk);
 			vco = bxt_de_pll_vco(dev_priv, cdclk);
 		}
 
@@ -2051,7 +2041,7 @@  static int cnl_modeset_calc_cdclk(struct drm_atomic_state *state)
 	intel_state->cdclk.logical.cdclk = cdclk;
 
 	if (!intel_state->active_crtcs) {
-		cdclk = cnl_calc_cdclk(0);
+		cdclk = cnl_calc_cdclk(intel_state->cdclk.force_min_cdclk);
 		vco = cnl_cdclk_pll_vco(dev_priv, cdclk);
 
 		intel_state->cdclk.actual.vco = vco;
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 8544de5ba687..b474d2d3e9ba 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11924,6 +11924,12 @@  static int intel_modeset_checks(struct drm_atomic_state *state)
 		return -EINVAL;
 	}
 
+	/* keep the current setting */
+	if (!intel_state->cdclk.force_min_cdclk_changed)
+		intel_state->cdclk.force_min_cdclk =
+			dev_priv->cdclk.force_min_cdclk;
+
+
 	intel_state->modeset = true;
 	intel_state->active_crtcs = dev_priv->active_crtcs;
 	intel_state->cdclk.logical = dev_priv->cdclk.logical;
@@ -12016,7 +12022,7 @@  static int intel_atomic_check(struct drm_device *dev,
 	struct drm_crtc *crtc;
 	struct drm_crtc_state *old_crtc_state, *crtc_state;
 	int ret, i;
-	bool any_ms = false;
+	bool any_ms = intel_state->cdclk.force_min_cdclk_changed;
 
 	ret = drm_atomic_helper_check_modeset(dev, state);
 	if (ret)
@@ -12545,6 +12551,8 @@  static int intel_atomic_commit(struct drm_device *dev,
 		dev_priv->active_crtcs = intel_state->active_crtcs;
 		dev_priv->cdclk.logical = intel_state->cdclk.logical;
 		dev_priv->cdclk.actual = intel_state->cdclk.actual;
+		dev_priv->cdclk.force_min_cdclk =
+			intel_state->cdclk.force_min_cdclk;
 	}
 
 	drm_atomic_state_get(state);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index bfffe27d887a..db287fbe9abc 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -368,6 +368,9 @@  struct intel_atomic_state {
 		 * state only when all crtc's are DPMS off.
 		 */
 		struct intel_cdclk_state actual;
+
+		int force_min_cdclk;
+		bool force_min_cdclk_changed;
 	} cdclk;
 
 	bool dpll_set, modeset;