Re: [PATCH 1/2] drm/i915/ddi: Get AUX power domain for DP main link too

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Jun 21, 2018 at 06:58:29PM +0300, Imre Deak wrote:
> So far we got an AUX power domain reference only for the duration of DP
> AUX transfers. However, the followings suggest 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).
> - 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
>   test pattern trying to toggle the AUX power well will time out.
> - 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.
> 
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
> Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
> Signed-off-by: Imre Deak <imre.deak@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_ddi.c     | 33 +++++++++++++++++++++++++++++----
>  drivers/gpu/drm/i915/intel_display.c | 12 +++++++++++-
>  drivers/gpu/drm/i915/intel_drv.h     |  3 ++-
>  3 files changed, 42 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index 044fe1fb9872..b09cb6969bbb 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1983,15 +1983,36 @@ bool intel_ddi_get_hw_state(struct intel_encoder *encoder,
>  	return ret;
>  }
>  
> -static u64 intel_ddi_get_power_domains(struct intel_encoder *encoder)
> +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_type(crtc_state, INTEL_OUTPUT_HDMI)) {

I would use intel_crtc_has_dp_encoder() here so that one doesn't
have to think "what is not HDMI?".

> +		struct intel_dp *intel_dp = &dig_port->dp;
> +
> +		domains |= BIT_ULL(intel_dp->aux_power_domain);
> +	}
> +
> +	return domains;
>  }
>  
>  void intel_ddi_enable_pipe_clock(const struct intel_crtc_state *crtc_state)
> @@ -2631,6 +2652,8 @@ 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_dp->aux_power_domain);
> +
>  	intel_dp_set_link_params(intel_dp, crtc_state->port_clock,
>  				 crtc_state->lane_count, is_mst);
>  
> @@ -2775,6 +2798,8 @@ 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_dp->aux_power_domain);
>  }
>  
>  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..d9fefcec4b1a 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);
> +		/*
> +		 * In case of a dangling encoder without a crtc we still need
> +		 * to get power domain refs. Such encoders will be disabled
> +		 * dropping these references.
> +		 */
> +		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
> -- 
> 2.13.2

-- 
Ville Syrjälä
Intel
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