[Intel-gfx] [PATCH v3] drm/i915/ddi: Get AUX power domain for DP main link too

Imre Deak imre.deak at intel.com
Thu Jun 21 19:54:00 UTC 2018


On Thu, Jun 21, 2018 at 01:14:30PM -0700, Dhinakaran Pandiyan wrote:
> On Thu, 2018-06-21 at 21:44 +0300, Imre Deak wrote:
> > So far we got an AUX power domain reference only for the duration of
> > DP
> > AUX transfers. However, the following suggests that we also need
> > these
> > for main link functionality:
> > - The specification doesn't state whether it's needed or not for main
> >   link functionality, but suggests that these power wells need to be
> >   enabled already during display core initialization (Sequences to
> >   Initialize Display).
> Hmm. The sequence also says "If an Aux channel will not be used, it
> does not need to be powered up."

Well, I consider that hints at not using the port at all for DP, since
for DP you will need AUX.

> 
> > - For PSR we need to keep the AUX power well enabled.
> > - On ICL combo PHY ports (non-TC) the AUX power well is needed for
> >   link training too: while the port is enabled with a DP link
> > training
> I don't see this in the spec, is this something you observed?

Yes.

> 
> >   test pattern trying to toggle the AUX power well will time out.
> 
> Can we enable AUX power well before link training starts and disable
> after we are done training? Is that enough?

That was my first idea too, but given the rest of the points I consider
it a safer option to enable it for main link functionality.

> 
> > - On ICL MG PHY ports (TC) the AUX power well is needed also for main
> >   link functionality (both in DP and HDMI modes).
> > - Windows enables these power wells both for main and AUX lane
> >   functionality.
> > 
> > Based on the above take an AUX power reference for main link
> > functionality too. This makes a difference only on GEN10+ (GLK+)
> > platforms, where we have separate port specific AUX power wells.
> > 
> > For PSR we still need to distinguish between port A and the other
> > ports, since on port A DC states must stay enabled for main link
> > functionality, but DC states must be disabled for driver initiated
> > AUX transfers. So re-use the corresponding helper from intel_psr.c.
> > 
> > Since we take now a reference for main link functionality on all DP
> > ports we can forgo taking the separate power ref for PSR
> > functionality.
> > 
> > v2:
> > - Make sure DC states stay enabled when taking the ref on port A.
> >   (Ville)
> > 
> > v3: (Ville)
> > - Fix comment about logic for encoders without a crtc state and
> >   add FIXME note for a simplification to avoid calling
> > get_power_domains
> >   in such cases.
> > - Use intel_crtc_has_dp_encoder() instead !intel_crtc_has_type(HDMI).
> > 
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_ddi.c        | 54
> > ++++++++++++++++++++++++++++++---
> >  drivers/gpu/drm/i915/intel_display.c    | 12 +++++++-
> >  drivers/gpu/drm/i915/intel_drv.h        |  3 +-
> >  drivers/gpu/drm/i915/intel_psr.c        | 41 ---------------------
> > ----
> >  drivers/gpu/drm/i915/intel_runtime_pm.c |  1 +
> >  5 files changed, 64 insertions(+), 47 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_ddi.c
> > b/drivers/gpu/drm/i915/intel_ddi.c
> > index 044fe1fb9872..0319825b725b 100644
> > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > @@ -1983,15 +1983,55 @@ bool intel_ddi_get_hw_state(struct
> > intel_encoder *encoder,
> >  	return ret;
> >  }
> >  
> > -static u64 intel_ddi_get_power_domains(struct intel_encoder
> > *encoder)
> > +static inline enum intel_display_power_domain
> > +intel_ddi_main_link_aux_domain(struct intel_dp *intel_dp)
> > +{
> > +	/* CNL HW requires corresponding AUX IOs to be powered up
> > for PSR with
> > +	 * DC states enabled at the same time, while for driver
> > initiated AUX
> > +	 * transfers we need the same AUX IOs to be powered but with
> > DC states
> > +	 * disabled. Accordingly use the AUX power domain here which
> > leaves DC
> > +	 * states enabled.
> > +	 * However, for non-A AUX ports the corresponding non-EDP
> > transcoders
> > +	 * would have already enabled power well 2 and DC_OFF. This
> > means we can
> > +	 * acquire a wider POWER_DOMAIN_AUX_{B,C,D,F} reference
> > instead of a
> > +	 * specific AUX_IO reference without powering up any extra
> > wells.
> > +	 * Note that PSR is enabled only on Port A even though this
> > function
> > +	 * returns the correct domain for other ports too.
> > +	 */
> > +	return intel_dp->aux_ch == AUX_CH_A ? POWER_DOMAIN_AUX_IO_A
> > :
> > +					      intel_dp-
> > >aux_power_domain;
> > +}
> > +
> > +static u64 intel_ddi_get_power_domains(struct intel_encoder
> > *encoder,
> > +				       struct intel_crtc_state
> > *crtc_state)
> >  {
> >  	struct intel_digital_port *dig_port =
> > enc_to_dig_port(&encoder->base);
> >  	enum pipe pipe;
> > +	u64 domains;
> >  
> > -	if (intel_ddi_get_hw_state(encoder, &pipe))
> > -		return BIT_ULL(dig_port->ddi_io_power_domain);
> > +	if (!intel_ddi_get_hw_state(encoder, &pipe))
> > +		return 0;
> >  
> > -	return 0;
> > +	domains = BIT_ULL(dig_port->ddi_io_power_domain);
> > +	if (!crtc_state)
> > +		return domains;
> > +
> > +	/*
> > +	 * TODO: Add support for MST encoders. Atm, the following
> > should never
> > +	 * happen since this function will be called only for the
> > primary
> > +	 * encoder which doesn't have its own pipe/crtc_state.
> > +	 */
> > +	if (WARN_ON(intel_crtc_has_type(crtc_state,
> > INTEL_OUTPUT_DP_MST)))
> > +		return domains;
> > +
> > +	/* AUX power is only needed for (e)DP mode, not for HDMI. */
> > +	if (intel_crtc_has_dp_encoder(crtc_state)) {
> > +		struct intel_dp *intel_dp = &dig_port->dp;
> > +
> > +		domains |=
> > BIT_ULL(intel_ddi_main_link_aux_domain(intel_dp));
> > +	}
> > +
> > +	return domains;
> >  }
> >  
> >  void intel_ddi_enable_pipe_clock(const struct intel_crtc_state
> > *crtc_state)
> > @@ -2631,6 +2671,9 @@ static void intel_ddi_pre_enable_dp(struct
> > intel_encoder *encoder,
> >  
> >  	WARN_ON(is_mst && (port == PORT_A || port == PORT_E));
> >  
> > +	intel_display_power_get(dev_priv,
> > +				intel_ddi_main_link_aux_domain(intel
> > _dp));
> > +
> >  	intel_dp_set_link_params(intel_dp, crtc_state->port_clock,
> >  				 crtc_state->lane_count, is_mst);
> >  
> > @@ -2775,6 +2818,9 @@ static void intel_ddi_post_disable_dp(struct
> > intel_encoder *encoder,
> >  	intel_display_power_put(dev_priv, dig_port-
> > >ddi_io_power_domain);
> >  
> >  	intel_ddi_clk_disable(encoder);
> > +
> > +	intel_display_power_put(dev_priv,
> > +				intel_ddi_main_link_aux_domain(intel
> > _dp));
> >  }
> >  
> >  static void intel_ddi_post_disable_hdmi(struct intel_encoder
> > *encoder,
> > diff --git a/drivers/gpu/drm/i915/intel_display.c
> > b/drivers/gpu/drm/i915/intel_display.c
> > index 2c8fef3ede54..ce615f89b43a 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -15676,11 +15676,21 @@ get_encoder_power_domains(struct
> > drm_i915_private *dev_priv)
> >  	for_each_intel_encoder(&dev_priv->drm, encoder) {
> >  		u64 get_domains;
> >  		enum intel_display_power_domain domain;
> > +		struct intel_crtc_state *crtc_state;
> >  
> >  		if (!encoder->get_power_domains)
> >  			continue;
> >  
> > -		get_domains = encoder->get_power_domains(encoder);
> > +		/*
> > +		 * For MST and inactive encoders we don't have a
> > crtc state.
> > +		 * FIXME: no need to call get_power_domains in such
> > cases, it
> > +		 * will always return 0.
> > +		 */
> > +		crtc_state = encoder->base.crtc ?
> > +			     to_intel_crtc_state(encoder->base.crtc-
> > >state) :
> > +			     NULL;
> > +
> > +		get_domains = encoder->get_power_domains(encoder,
> > crtc_state);
> >  		for_each_power_domain(domain, get_domains)
> >  			intel_display_power_get(dev_priv, domain);
> >  	}
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h
> > b/drivers/gpu/drm/i915/intel_drv.h
> > index 0c3ac0eafde0..7174429d930a 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -254,7 +254,8 @@ struct intel_encoder {
> >  			   struct intel_crtc_state *pipe_config);
> >  	/* Returns a mask of power domains that need to be
> > referenced as part
> >  	 * of the hardware state readout code. */
> > -	u64 (*get_power_domains)(struct intel_encoder *encoder);
> > +	u64 (*get_power_domains)(struct intel_encoder *encoder,
> > +				 struct intel_crtc_state
> > *crtc_state);
> >  	/*
> >  	 * Called during system suspend after all pending requests
> > for the
> >  	 * encoder are flushed (for example for DP AUX transactions)
> > and
> > diff --git a/drivers/gpu/drm/i915/intel_psr.c
> > b/drivers/gpu/drm/i915/intel_psr.c
> > index d4cd19fea148..eecdd8b5b5e0 100644
> > --- a/drivers/gpu/drm/i915/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/intel_psr.c
> > @@ -56,43 +56,6 @@
> >  #include "intel_drv.h"
> >  #include "i915_drv.h"
> >  
> > -static inline enum intel_display_power_domain
> > -psr_aux_domain(struct intel_dp *intel_dp)
> > -{
> > -	/* CNL HW requires corresponding AUX IOs to be powered up
> > for PSR.
> > -	 * However, for non-A AUX ports the corresponding non-EDP
> > transcoders
> > -	 * would have already enabled power well 2 and DC_OFF. This
> > means we can
> > -	 * acquire a wider POWER_DOMAIN_AUX_{B,C,D,F} reference
> > instead of a
> > -	 * specific AUX_IO reference without powering up any extra
> > wells.
> > -	 * Note that PSR is enabled only on Port A even though this
> > function
> > -	 * returns the correct domain for other ports too.
> > -	 */
> > -	return intel_dp->aux_ch == AUX_CH_A ? POWER_DOMAIN_AUX_IO_A
> > :
> > -					      intel_dp-
> > >aux_power_domain;
> > -}
> > -
> > -static void psr_aux_io_power_get(struct intel_dp *intel_dp)
> > -{
> > -	struct intel_digital_port *intel_dig_port =
> > dp_to_dig_port(intel_dp);
> > -	struct drm_i915_private *dev_priv = to_i915(intel_dig_port-
> > >base.base.dev);
> > -
> > -	if (INTEL_GEN(dev_priv) < 10)
> > -		return;
> > -
> > -	intel_display_power_get(dev_priv, psr_aux_domain(intel_dp));
> > -}
> > -
> > -static void psr_aux_io_power_put(struct intel_dp *intel_dp)
> > -{
> > -	struct intel_digital_port *intel_dig_port =
> > dp_to_dig_port(intel_dp);
> > -	struct drm_i915_private *dev_priv = to_i915(intel_dig_port-
> > >base.base.dev);
> > -
> > -	if (INTEL_GEN(dev_priv) < 10)
> > -		return;
> > -
> > -	intel_display_power_put(dev_priv, psr_aux_domain(intel_dp));
> > -}
> > -
> >  void intel_psr_irq_control(struct drm_i915_private *dev_priv, bool
> > debug)
> >  {
> >  	u32 debug_mask, mask;
> > @@ -595,8 +558,6 @@ static void hsw_psr_enable_source(struct intel_dp
> > *intel_dp,
> >  	struct drm_i915_private *dev_priv = to_i915(dev);
> >  	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> >  
> > -	psr_aux_io_power_get(intel_dp);
> > -
> >  	/* Only HSW and BDW have PSR AUX registers that need to be
> > setup. SKL+
> >  	 * use hardcoded values PSR AUX transactions
> >  	 */
> > @@ -717,8 +678,6 @@ static void hsw_psr_disable(struct intel_dp
> > *intel_dp,
> >  		else
> >  			WARN_ON(I915_READ(EDP_PSR_CTL) &
> > EDP_PSR_ENABLE);
> >  	}
> > -
> > -	psr_aux_io_power_put(intel_dp);
> >  }
> >  
> >  /**
> > diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > index de3a81034f77..2969787201ef 100644
> > --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> > @@ -1824,6 +1824,7 @@ void intel_display_power_put(struct
> > drm_i915_private *dev_priv,
> >  	BIT_ULL(POWER_DOMAIN_INIT))
> >  #define GLK_DISPLAY_AUX_A_POWER_DOMAINS (		\
> >  	BIT_ULL(POWER_DOMAIN_AUX_A) |		\
> > +	BIT_ULL(POWER_DOMAIN_AUX_IO_A) |		\
> >  	BIT_ULL(POWER_DOMAIN_INIT))
> >  #define GLK_DISPLAY_AUX_B_POWER_DOMAINS (		\
> >  	BIT_ULL(POWER_DOMAIN_AUX_B) |		\


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