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

Jani Nikula jani.nikula at linux.intel.com
Fri Mar 22 09:38:20 UTC 2019


On Thu, 21 Mar 2019, Clinton Taylor <Clinton.A.Taylor at intel.com> wrote:
> 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?

IIUC that can only be done when we don't care about audio, and AFAIK,
ahem, certain other OS has opted not to support this.

BR,
Jani.



>
>
>>   
>>   	/*
>> @@ -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>
>
>
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Jani Nikula, Intel Open Source Graphics Center


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