Re: [PATCH v11 2/6] drm/i915: Parse EDID probed modes for DRRS support

[Jani Nikula <jani.nikula@linux.intel.com>]

Reviewed-by: Jani Nikula <jani.nikula@intel.com>


On Sat, 05 Apr 2014, Vandana Kannan <vandana.kannan@intel.com> wrote:
> From: Pradeep Bhat <pradeep.bhat@intel.com>
>
> This patch and finds out the lowest refresh rate supported for the resolution
> same as the fixed_mode.
> It also checks the VBT fields to see if panel supports seamless DRRS or not.
> Based on above data it marks whether eDP panel supports seamless DRRS or not.
> This information is needed for supporting seamless DRRS switch for certain
> power saving usecases. This patch is tested by enabling the DRM logs and
> user should see whether Seamless DRRS is supported or not.
>
> v2: Daniel's review comments
> Modified downclock deduction based on intel_find_panel_downclock
>
> v3: Chris's review comments
> Moved edp_downclock_avail and edp_downclock to intel_panel
>
> v4: Jani's review comments.
> Changed name of the enum edp_panel_type to drrs_support type.
> Change is_drrs_supported to drrs_support of type enum drrs_support_type.
>
> v5: Incorporated Jani's review comments
> Modify intel_dp_drrs_initialize to return downclock mode. Support for Gen7
> and above.
>
> v6: Incorporated Chris's review comments.
> Changed initialize to init in intel_drrs_initialize
>
> v7: Incorporated Jani's review comments.
> Removed edp_downclock and edp_downclock_avail. Return NULL explicitly.
> Make drrs_state and unnamed struct. Move Gen based check inside drrs_init.
>
> v8: Made changes to track PSR enable/disable throughout system use (instead
> of just in the init sequence) for disabling/enabling DRRS. Jani's review
> comments.
>
> v9: PSR tracking will be done as part of idleness detection patch. Removed
> PSR state tracker in i915_drrs. Jani's review comments.
>
> v10: Added log for DRRS not supported in drrs_init
>
> v11: Modification in drrs_init. suggested by Jani
>
> Signed-off-by: Pradeep Bhat <pradeep.bhat@intel.com>
> Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c  | 44 +++++++++++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/i915/intel_drv.h | 16 +++++++++++++++
>  2 files changed, 59 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index e48d47c..517a8cc 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -3632,6 +3632,42 @@ intel_dp_init_panel_power_sequencer_registers(struct drm_device *dev,
>  		      I915_READ(pp_div_reg));
>  }
>  
> +static struct drm_display_mode *
> +intel_dp_drrs_init(struct intel_digital_port *intel_dig_port,
> +			struct intel_connector *intel_connector,
> +			struct drm_display_mode *fixed_mode)
> +{
> +	struct drm_connector *connector = &intel_connector->base;
> +	struct intel_dp *intel_dp = &intel_dig_port->dp;
> +	struct drm_device *dev = intel_dig_port->base.base.dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct drm_display_mode *downclock_mode = NULL;
> +
> +	if (INTEL_INFO(dev)->gen <= 6) {
> +		DRM_DEBUG_KMS("DRRS supported for Gen7 and above\n");
> +		return NULL;
> +	}
> +
> +	if (dev_priv->vbt.drrs_type != SEAMLESS_DRRS_SUPPORT) {
> +		DRM_INFO("VBT doesn't support DRRS\n");
> +		return NULL;
> +	}
> +
> +	downclock_mode = intel_find_panel_downclock
> +					(dev, fixed_mode, connector);
> +
> +	if (!downclock_mode) {
> +		DRM_INFO("DRRS not supported\n");
> +		return NULL;
> +	}
> +
> +	intel_dp->drrs_state.type = dev_priv->vbt.drrs_type;
> +
> +	intel_dp->drrs_state.refresh_rate_type = DRRS_HIGH_RR;
> +	DRM_INFO("seamless DRRS supported for eDP panel.\n");
> +	return downclock_mode;
> +}
> +
>  static bool intel_edp_init_connector(struct intel_dp *intel_dp,
>  				     struct intel_connector *intel_connector,
>  				     struct edp_power_seq *power_seq)
> @@ -3641,10 +3677,13 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
>  	struct drm_device *dev = intel_dig_port->base.base.dev;
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  	struct drm_display_mode *fixed_mode = NULL;
> +	struct drm_display_mode *downclock_mode = NULL;
>  	bool has_dpcd;
>  	struct drm_display_mode *scan;
>  	struct edid *edid;
>  
> +	intel_dp->drrs_state.type = DRRS_NOT_SUPPORTED;
> +
>  	if (!is_edp(intel_dp))
>  		return true;
>  
> @@ -3687,6 +3726,9 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
>  	list_for_each_entry(scan, &connector->probed_modes, head) {
>  		if ((scan->type & DRM_MODE_TYPE_PREFERRED)) {
>  			fixed_mode = drm_mode_duplicate(dev, scan);
> +			downclock_mode = intel_dp_drrs_init(
> +						intel_dig_port,
> +						intel_connector, fixed_mode);
>  			break;
>  		}
>  	}
> @@ -3700,7 +3742,7 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
>  	}
>  	mutex_unlock(&dev->mode_config.mutex);
>  
> -	intel_panel_init(&intel_connector->panel, fixed_mode, NULL);
> +	intel_panel_init(&intel_connector->panel, fixed_mode, downclock_mode);
>  	intel_panel_setup_backlight(connector);
>  
>  	return true;
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 42762b7..286d4fb 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -482,6 +482,17 @@ struct intel_hdmi {
>  
>  #define DP_MAX_DOWNSTREAM_PORTS		0x10
>  
> +/**
> + * HIGH_RR is the highest eDP panel refresh rate read from EDID
> + * LOW_RR is the lowest eDP panel refresh rate found from EDID
> + * parsing for same resolution.
> + */
> +enum edp_drrs_refresh_rate_type {
> +	DRRS_HIGH_RR,
> +	DRRS_LOW_RR,
> +	DRRS_MAX_RR, /* RR count */
> +};
> +
>  struct intel_dp {
>  	uint32_t output_reg;
>  	uint32_t aux_ch_ctl_reg;
> @@ -520,6 +531,11 @@ struct intel_dp {
>  				     bool has_aux_irq,
>  				     int send_bytes,
>  				     uint32_t aux_clock_divider);
> +	struct {
> +		enum drrs_support_type type;
> +		enum edp_drrs_refresh_rate_type refresh_rate_type;
> +	} drrs_state;
> +
>  };
>  
>  struct intel_digital_port {
> -- 
> 1.9.1
>

-- 
Jani Nikula, Intel Open Source Technology Center