[Intel-gfx] [PATCH v3 5/5] drm/i915/vbt: Parse power conservation features block

[Souza, Jose]

On Thu, 2019-11-28 at 16:29 +0200, Jani Nikula wrote:
> On Wed, 27 Nov 2019, José Roberto de Souza <jose.souza at intel.com>
> wrote:
> > From VBT 228+ this is block that PSR and other power saving
> > features configuration should be read from.
> > 
> > v3:
> > Using DRRS from this new block
> > 
> > Cc: Matt Roper <matthew.d.roper at intel.com>
> > Cc: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
> > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_bios.c     | 36
> > +++++++++++++++++--
> >  drivers/gpu/drm/i915/display/intel_vbt_defs.h | 29 +++++++++++++++
> >  2 files changed, 62 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_bios.c
> > b/drivers/gpu/drm/i915/display/intel_bios.c
> > index f6a9a5ccb556..2d06f1f5734d 100644
> > --- a/drivers/gpu/drm/i915/display/intel_bios.c
> > +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> > @@ -659,16 +659,45 @@ parse_driver_features(struct drm_i915_private
> > *dev_priv,
> >  			dev_priv->vbt.int_lvds_support = 0;
> >  	}
> >  
> > -	DRM_DEBUG_KMS("DRRS State Enabled:%d\n", driver->drrs_enabled);
> > +	if (bdb->version < 228) {
> > +		DRM_DEBUG_KMS("DRRS State Enabled:%d\n", driver-
> > >drrs_enabled);
> > +		/*
> > +		 * If DRRS is not supported, drrs_type has to be set to
> > 0.
> > +		 * This is because, VBT is configured in such a way
> > that
> > +		 * static DRRS is 0 and DRRS not supported is
> > represented by
> > +		 * driver->drrs_enabled=false
> > +		 */
> > +		if (!driver->drrs_enabled)
> > +			dev_priv->vbt.drrs_type = DRRS_NOT_SUPPORTED;
> > +
> > +		dev_priv->vbt.psr.enable = driver->psr_enabled;
> > +	}
> > +}
> 
> Maybe this review comment gives you an idea what we have to think of
> and
> deal with when working with VBT and VBT parsing.
> 
> Imagine VBT version >= 228 without lvds power block, and
> driver->drrs_enabled == false.

That happened in the past with other obsolete blocks?
If not I guess we should trust VBT and not try to over handled this
cases that might never happen.

VBT versions 228 will be used in TGL+ that supports more than one eDP
panel so this global DRRS/PSR disable would be applied to all eDP
panels? (When we support more than one instance of PSR and DRRS)

> 
> > +
> > +static void
> > +parse_power_conservation_features(struct drm_i915_private
> > *dev_priv,
> > +				  const struct bdb_header *bdb)
> > +{
> > +	const struct bdb_lfp_power *power;
> > +	u8 panel_type = dev_priv->vbt.panel_type;
> > +
> > +	if (bdb->version < 228)
> > +		return;
> > +
> > +	power = find_section(bdb, BDB_LVDS_POWER);
> > +	if (!power)
> > +		return;
> > +
> > +	dev_priv->vbt.psr.enable = power->psr & (1 << panel_type);
> > +
> >  	/*
> >  	 * If DRRS is not supported, drrs_type has to be set to 0.
> >  	 * This is because, VBT is configured in such a way that
> >  	 * static DRRS is 0 and DRRS not supported is represented by
> >  	 * driver->drrs_enabled=false
> >  	 */
> > -	if (!driver->drrs_enabled)
> > +	if (!(power->drrs & (1 << panel_type)))
> >  		dev_priv->vbt.drrs_type = DRRS_NOT_SUPPORTED;
> > -	dev_priv->vbt.psr.enable = driver->psr_enabled;
> >  }
> >  
> >  static void
> > @@ -1973,6 +2002,7 @@ void intel_bios_init(struct drm_i915_private
> > *dev_priv)
> >  	parse_lfp_backlight(dev_priv, bdb);
> >  	parse_sdvo_panel_data(dev_priv, bdb);
> >  	parse_driver_features(dev_priv, bdb);
> > +	parse_power_conservation_features(dev_priv, bdb);
> >  	parse_edp(dev_priv, bdb);
> >  	parse_psr(dev_priv, bdb);
> >  	parse_mipi_config(dev_priv, bdb);
> > diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> > b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> > index f0338da3a82a..98b71dc32d2a 100644
> > --- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> > +++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
> > @@ -793,6 +793,35 @@ struct bdb_lfp_backlight_data {
> >  	struct lfp_backlight_control_method backlight_control[16];
> >  } __packed;
> >  
> > +/*
> > + * Block 44 - LFP Power Conservation Features Block
> > + */
> > +
> > +struct als_data_entry {
> > +	u16 backlight_adjust;
> > +	u16 lux;
> > +} __packed;
> > +
> > +struct agressiveness_profile_entry {
> > +	u8 dpst_agressiveness : 4;
> > +	u8 lace_agressiveness : 4;
> 
> Nitpick, none of the other bitfields have spaces around : here.
> 
> > +} __packed;
> > +
> > +struct bdb_lfp_power {
> 
> The idea is that the bdb struct name is the same as the block id
> enum,
> just lower case. Please fix either.

Will fix the block id to match BSpec.

> 
> BR,
> Jani.
> 
> 
> > +	u8 lfp_feature_bits;
> > +	struct als_data_entry als[5];
> > +	u8 lace_aggressiveness_profile;
> > +	u16 dpst;
> > +	u16 psr;
> > +	u16 drrs;
> > +	u16 lace_support;
> > +	u16 adt;
> > +	u16 dmrrs;
> > +	u16 adb;
> > +	u16 lace_enabled_status;
> > +	struct agressiveness_profile_entry aggressivenes[16];
> > +} __packed;
> > +
> >  /*
> >   * Block 52 - MIPI Configuration Block
> >   */