[Intel-gfx] [RFC v2] drm/i915/pps: Add PPS power domain

[Imre Deak]

On Wed, Jan 06, 2021 at 10:04:38AM +0530, Anshuman Gupta wrote:
> It abstracts getting the AUX power domain in pps_lock under
> PPS power domain. This makes sure that the platforms which really
> requires AUX power in order to access PPS registers will get the
> reference to necessary power wells.
> 
> PPS power domain requires only to track the AUX_A associated
> power wells as the platforms need AUX power in order to access PPS
> registers supports eDP only on PORT_A.
> 
> v2:
> - Fixed missed POWER_DOMAIN_PPS in pps_unlock().
> 
> Cc: Imre Deak <imre.deak at intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display_power.c | 7 +++++++
>  drivers/gpu/drm/i915/display/intel_display_power.h | 1 +
>  drivers/gpu/drm/i915/display/intel_dp.c            | 7 ++-----
>  3 files changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
> index d52374f01316..1dc4ca9e5d1a 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -107,6 +107,8 @@ intel_display_power_domain_str(enum intel_display_power_domain domain)
>  		return "VGA";
>  	case POWER_DOMAIN_AUDIO:
>  		return "AUDIO";
> +	case POWER_DOMAIN_PPS:
> +		return "PPS";
>  	case POWER_DOMAIN_AUX_A:
>  		return "AUX_A";
>  	case POWER_DOMAIN_AUX_B:
> @@ -2651,11 +2653,13 @@ intel_display_power_put_mask_in_set(struct drm_i915_private *i915,
>  	BIT_ULL(POWER_DOMAIN_GT_IRQ) |			\
>  	BIT_ULL(POWER_DOMAIN_MODESET) |			\
>  	BIT_ULL(POWER_DOMAIN_AUX_A) |			\
> +	BIT_ULL(POWER_DOMAIN_PPS) |			\
>  	BIT_ULL(POWER_DOMAIN_GMBUS) |			\
>  	BIT_ULL(POWER_DOMAIN_INIT))
>  #define BXT_DPIO_CMN_A_POWER_DOMAINS (			\
>  	BIT_ULL(POWER_DOMAIN_PORT_DDI_A_LANES) |		\
>  	BIT_ULL(POWER_DOMAIN_AUX_A) |			\
> +	BIT_ULL(POWER_DOMAIN_PPS) |			\
>  	BIT_ULL(POWER_DOMAIN_INIT))
>  #define BXT_DPIO_CMN_BC_POWER_DOMAINS (			\
>  	BIT_ULL(POWER_DOMAIN_PORT_DDI_B_LANES) |		\
> @@ -2688,6 +2692,7 @@ intel_display_power_put_mask_in_set(struct drm_i915_private *i915,
>  #define GLK_DPIO_CMN_A_POWER_DOMAINS (			\
>  	BIT_ULL(POWER_DOMAIN_PORT_DDI_A_LANES) |		\
>  	BIT_ULL(POWER_DOMAIN_AUX_A) |			\
> +	BIT_ULL(POWER_DOMAIN_PPS) |			\
>  	BIT_ULL(POWER_DOMAIN_INIT))
>  #define GLK_DPIO_CMN_B_POWER_DOMAINS (			\
>  	BIT_ULL(POWER_DOMAIN_PORT_DDI_B_LANES) |		\
> @@ -2700,6 +2705,7 @@ intel_display_power_put_mask_in_set(struct drm_i915_private *i915,
>  #define GLK_DISPLAY_AUX_A_POWER_DOMAINS (		\
>  	BIT_ULL(POWER_DOMAIN_AUX_A) |		\
>  	BIT_ULL(POWER_DOMAIN_AUX_IO_A) |		\
> +	BIT_ULL(POWER_DOMAIN_PPS) |			\
>  	BIT_ULL(POWER_DOMAIN_INIT))
>  #define GLK_DISPLAY_AUX_B_POWER_DOMAINS (		\
>  	BIT_ULL(POWER_DOMAIN_AUX_B) |		\
> @@ -2712,6 +2718,7 @@ intel_display_power_put_mask_in_set(struct drm_i915_private *i915,
>  	BIT_ULL(POWER_DOMAIN_GT_IRQ) |			\
>  	BIT_ULL(POWER_DOMAIN_MODESET) |			\
>  	BIT_ULL(POWER_DOMAIN_AUX_A) |			\
> +	BIT_ULL(POWER_DOMAIN_PPS) |			\
>  	BIT_ULL(POWER_DOMAIN_GMBUS) |			\
>  	BIT_ULL(POWER_DOMAIN_INIT))
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.h b/drivers/gpu/drm/i915/display/intel_display_power.h
> index bc30c479be53..7642be3c8e2e 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.h
> @@ -55,6 +55,7 @@ enum intel_display_power_domain {
>  	POWER_DOMAIN_PORT_OTHER,
>  	POWER_DOMAIN_VGA,
>  	POWER_DOMAIN_AUDIO,
> +	POWER_DOMAIN_PPS,
>  	POWER_DOMAIN_AUX_A,
>  	POWER_DOMAIN_AUX_B,
>  	POWER_DOMAIN_AUX_C,
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 8a00e609085f..99b4bec3c926 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -895,8 +895,7 @@ pps_lock(struct intel_dp *intel_dp)
>  	 * See intel_power_sequencer_reset() why we need
>  	 * a power domain reference here.
>  	 */
> -	wakeref = intel_display_power_get(dev_priv,
> -					  intel_aux_power_domain(dp_to_dig_port(intel_dp)));
> +	wakeref = intel_display_power_get(dev_priv, POWER_DOMAIN_PPS);

The purpose of this reference is to prevent a race when resetting the
PPS state (see the comment), so I think we could reuse
POWER_DOMAIN_DISPLAY_CORE instead of adding a new domain.

>  
>  	mutex_lock(&dev_priv->pps_mutex);
>  
> @@ -909,9 +908,7 @@ pps_unlock(struct intel_dp *intel_dp, intel_wakeref_t wakeref)
>  	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
>  
>  	mutex_unlock(&dev_priv->pps_mutex);
> -	intel_display_power_put(dev_priv,
> -				intel_aux_power_domain(dp_to_dig_port(intel_dp)),
> -				wakeref);
> +	intel_display_power_put(dev_priv, POWER_DOMAIN_PPS, wakeref);
>  	return 0;
>  }
>  
> -- 
> 2.26.2
>