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

[Gupta, Anshuman]

> -----Original Message-----
> From: Imre Deak <imre.deak at intel.com>
> Sent: Wednesday, January 6, 2021 9:33 PM
> To: Gupta, Anshuman <anshuman.gupta at intel.com>
> Cc: intel-gfx at lists.freedesktop.org; Mason, Michael W
> <michael.w.mason at intel.com>; Nikula, Jani <jani.nikula at intel.com>; Ville
> Syrjälä <ville.syrjala at linux.intel.com>
> Subject: Re: [RFC v2] drm/i915/pps: Add PPS power domain
> 
> 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.
Thanks Imre for review, I will send a new patch with the fix.
Thanks,
Anshuman Gupta.
> 
> >
> >  	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
> >