[Intel-gfx] [CI 1/4] drm/i915: Force 2*96 MHz cdclk on glk/cnl when audio power is enabled

Clinton Taylor Clinton.A.Taylor at intel.com
Thu Mar 21 21:20:50 UTC 2019


On 3/20/19 6:54 AM, Imre Deak wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> 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.
>
> v2: Use atomic refcount for get_power, put_power so that we can
>      call each once(Abhay).
> v3: Reset power well 2 to avoid any transaction on iDisp link
>      during cdclk change(Abhay).
> v4: Remove Power well 2 reset workaround(Ville).
> v5: Remove unwanted Power well 2 register defined in v4(Abhay).
> v6:
> - Use a dedicated flag instead of state->modeset for min CDCLK changes
> - Make get/put audio power domain symmetric
> - Rebased on top of intel_wakeref tracking changes.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Abhay Kumar <abhay.kumar at intel.com>
> Tested-by: Abhay Kumar <abhay.kumar at intel.com>
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_drv.h      |  3 ++
>   drivers/gpu/drm/i915/intel_audio.c   | 64 ++++++++++++++++++++++++++++++++++--
>   drivers/gpu/drm/i915/intel_cdclk.c   | 30 ++++++-----------
>   drivers/gpu/drm/i915/intel_display.c |  9 ++++-
>   drivers/gpu/drm/i915/intel_drv.h     |  3 ++
>   5 files changed, 86 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index c65c2e6649df..6b10cee4e77f 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1624,6 +1624,8 @@ struct drm_i915_private {
>   		struct intel_cdclk_state actual;
>   		/* The current hardware cdclk state */
>   		struct intel_cdclk_state hw;
> +
> +		int force_min_cdclk;
>   	} cdclk;
>   
>   	/**
> @@ -1743,6 +1745,7 @@ struct drm_i915_private {
>   	 *
>   	 */
>   	struct mutex av_mutex;
> +	int audio_power_refcount;
>   
>   	struct {
>   		struct mutex mutex;
> diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
> index 502b57ce72ab..20324b0d34c7 100644
> --- a/drivers/gpu/drm/i915/intel_audio.c
> +++ b/drivers/gpu/drm/i915/intel_audio.c
> @@ -741,18 +741,78 @@ 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;
This will need to be revisited on later SOCs that may support cdclk 
rates < 192 Mhz.
> +
> +	/*
> +	 * 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 unsigned long i915_audio_component_get_power(struct device *kdev)
>   {
> +	struct drm_i915_private *dev_priv = kdev_to_i915(kdev);
> +	intel_wakeref_t ret;
> +
>   	/* Catch potential impedance mismatches before they occur! */
>   	BUILD_BUG_ON(sizeof(intel_wakeref_t) > sizeof(unsigned long));
>   
> -	return intel_display_power_get(kdev_to_i915(kdev), POWER_DOMAIN_AUDIO);
> +	ret = intel_display_power_get(dev_priv, 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);
> +
> +	return ret;
>   }
>   
>   static void i915_audio_component_put_power(struct device *kdev,
>   					   unsigned long cookie)
>   {
> -	intel_display_power_put(kdev_to_i915(kdev), POWER_DOMAIN_AUDIO, cookie);
> +	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(dev_priv, POWER_DOMAIN_AUDIO, cookie);
>   }
>   
>   static void i915_audio_component_codec_wake_override(struct device *kdev,
> diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
> index 21fb4e0d6c4e..7dcca84f31d1 100644
> --- a/drivers/gpu/drm/i915/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/intel_cdclk.c
> @@ -2187,19 +2187,8 @@ 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);

Do we have plans to support a 48Mhz BCLK?


>   
>   	/*
> @@ -2239,7 +2228,7 @@ 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);
>   
> @@ -2300,7 +2289,8 @@ 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 =
> @@ -2333,7 +2323,7 @@ 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 =
> @@ -2405,7 +2395,7 @@ 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;
> @@ -2444,10 +2434,10 @@ 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);
>   		}
>   
> @@ -2483,7 +2473,7 @@ 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;
> @@ -2519,7 +2509,7 @@ static int icl_modeset_calc_cdclk(struct drm_atomic_state *state)
>   		    cnl_compute_min_voltage_level(intel_state));
>   
>   	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 61acbaf2af75..b4199cd53349 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12973,6 +12973,11 @@ 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;
> @@ -13068,7 +13073,7 @@ 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;
>   
>   	/* Catch I915_MODE_FLAG_INHERITED */
>   	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state,
> @@ -13660,6 +13665,8 @@ 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 d9f188ef21f4..0b84e557c267 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -556,6 +556,9 @@ 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;

Some concerns about hard coded 96Mhz BCLK. however, that is the only 
frequency we currently support.

Reviewed-by: Clint Taylor <Clinton.A.Taylor at intel.com>





More information about the Intel-gfx mailing list