[Intel-gfx] [PATCH] drm/i915: Force 2*96 MHz cdclk on glk/cnl when audio power is enabled

Abhay Kumar abhay.kumar at intel.com
Sun Apr 29 20:39:13 UTC 2018


CDCLK has to be at least twice the BLCK regardless of audio. Audio
driver has to probe using this hook and increase the clock even in
absence of any display.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Abhay Kumar <abhay.kumar at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h      |  2 ++
 drivers/gpu/drm/i915/intel_audio.c   | 46 ++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_cdclk.c   | 34 +++++++-------------------
 drivers/gpu/drm/i915/intel_display.c |  7 +++++-
 drivers/gpu/drm/i915/intel_drv.h     |  1 +
 5 files changed, 63 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 193176bcddf5..34c31ef0761e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1708,6 +1708,8 @@ struct drm_i915_private {
 		struct intel_cdclk_state actual;
 		/* The current hardware cdclk state */
 		struct intel_cdclk_state hw;
+
+		int force_min_cdclk;
 	} cdclk;
 
 	/**
diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index 3ea566f99450..f001fcf05d3a 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -594,6 +594,7 @@ static void ilk_audio_codec_enable(struct intel_encoder *encoder,
 	I915_WRITE(aud_config, tmp);
 }
 
+
 /**
  * intel_audio_codec_enable - Enable the audio codec for HD audio
  * @encoder: encoder on which to enable audio
@@ -713,6 +714,48 @@ 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)->modeset = 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)
 {
 	intel_display_power_get(kdev_to_i915(kdev), POWER_DOMAIN_AUDIO);
@@ -732,6 +775,9 @@ static void i915_audio_component_codec_wake_override(struct device *kdev,
 	if (!IS_GEN9(dev_priv))
 		return;
 
+	if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
+		glk_force_audio_cdclk(dev_priv, true);
+
 	i915_audio_component_get_power(kdev);
 
 	/*
diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
index ebca83a44d9b..4086730018f9 100644
--- a/drivers/gpu/drm/i915/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/intel_cdclk.c
@@ -2141,24 +2141,6 @@ 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)
-		min_cdclk = max(2 * 96000, min_cdclk);
-
-	/*
 	 * On Valleyview some DSI panels lose (v|h)sync when the clock is lower
 	 * than 320000KHz.
 	 */
@@ -2195,7 +2177,7 @@ 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);
 
@@ -2256,7 +2238,7 @@ static int vlv_modeset_calc_cdclk(struct drm_atomic_state *state)
 		vlv_calc_voltage_level(dev_priv, 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;
 		intel_state->cdclk.actual.voltage_level =
@@ -2289,7 +2271,7 @@ static int bdw_modeset_calc_cdclk(struct drm_atomic_state *state)
 		bdw_calc_voltage_level(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;
 		intel_state->cdclk.actual.voltage_level =
@@ -2328,7 +2310,7 @@ static int skl_modeset_calc_cdclk(struct drm_atomic_state *state)
 		skl_calc_voltage_level(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;
@@ -2367,10 +2349,10 @@ 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);
 		}
 
@@ -2406,7 +2388,7 @@ static int cnl_modeset_calc_cdclk(struct drm_atomic_state *state)
 		    cnl_compute_min_voltage_level(intel_state));
 
 	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;
@@ -2439,7 +2421,7 @@ static int icl_modeset_calc_cdclk(struct drm_atomic_state *state)
 	intel_state->cdclk.logical.cdclk = cdclk;
 
 	if (!intel_state->active_crtcs) {
-		cdclk = icl_calc_cdclk(0, ref);
+		cdclk = icl_calc_cdclk(intel_state->cdclk.force_min_cdclk, ref);
 		vco = icl_calc_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 84ce66be88f2..7c369e15f193 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12023,6 +12023,10 @@ static int intel_modeset_checks(struct drm_atomic_state *state)
 		return -EINVAL;
 	}
 
+	/* keep the current setting */
+	if (!intel_state->modeset)
+		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;
@@ -12118,7 +12122,7 @@ 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->modeset;
 
 	/* Catch I915_MODE_FLAG_INHERITED */
 	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state,
@@ -12666,6 +12670,7 @@ 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 11a1932cde6e..79928505d0d0 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -461,6 +461,7 @@ struct intel_atomic_state {
 		 * state only when all crtc's are DPMS off.
 		 */
 		struct intel_cdclk_state actual;
+		int force_min_cdclk;
 	} cdclk;
 
 	bool dpll_set, modeset;
-- 
2.7.4



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