[Intel-gfx] [PATCH v9 3/6] drm/i915: Add support for DRRS to switch RR

Daniel Vetter daniel at ffwll.ch
Thu Apr 10 10:58:54 CEST 2014


On Thu, Apr 10, 2014 at 11:43:15AM +0300, Jani Nikula wrote:
> 
> Reviewed-by: Jani Nikula <jani.nikula at intel.com>
> 
> 
> On Sat, 05 Apr 2014, Vandana Kannan <vandana.kannan at intel.com> wrote:
> > From: Pradeep Bhat <pradeep.bhat at intel.com>
> >
> > This patch computes and stored 2nd M/N/TU for switching to different
> > refresh rate dynamically. PIPECONF_EDP_RR_MODE_SWITCH bit helps toggle
> > between alternate refresh rates programmed in 2nd M/N/TU registers.
> >
> > v2: Daniel's review comments
> > Computing M2/N2 in compute_config and storing it in crtc_config
> >
> > v3: Modified reference to edp_downclock and edp_downclock_avail based on the
> > changes made to move them from dev_private to intel_panel.
> >
> > v4: Modified references to is_drrs_supported based on the changes made to
> > rename it to drrs_support.
> >
> > v5: Jani's review comments
> > Removed superfluous return statements. Changed support for Gen 7 and above.
> > Corrected indentation. Re-structured the code which finds crtc and connector
> > from encoder. Changed some logs to be less verbose.
> >
> > v6: Modifying i915_drrs to include only intel connector as intel_dp can be
> > derived from intel connector when required.
> >
> > v7: As per internal review comments, acquiring mutex just before accessing
> > drrs RR. As per Chris's review comments, added documentation about the use
> > of locking in the function.
> >
> > v8: Incorporated Jani's review comments.
> > Removed reference to edp_downclock.
> >
> > v9: Jani's review comments. Modified comment in set_drrs. Changed index to
> > type edp_drrs_refresh_rate_type. Check if PSR is enabled before setting
> > registers fo DRRS.
> >
> > Signed-off-by: Pradeep Bhat <pradeep.bhat at intel.com>
> > Signed-off-by: Vandana Kannan <vandana.kannan at intel.com>
> > Cc: Jani Nikula <jani.nikula at linux.intel.com>

Queued for -next, thanks for the patch. One thing that's missing though is
the state readout and cross-check support for this new bit of crtc->config
data. We need to add that before putting this to real use.
-Daniel

> > ---
> >  drivers/gpu/drm/i915/i915_drv.h  |   5 ++
> >  drivers/gpu/drm/i915/i915_reg.h  |   1 +
> >  drivers/gpu/drm/i915/intel_dp.c  | 110 +++++++++++++++++++++++++++++++++++++++
> >  drivers/gpu/drm/i915/intel_drv.h |   6 ++-
> >  4 files changed, 121 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> > index 55addaa..9da8d83 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.h
> > +++ b/drivers/gpu/drm/i915/i915_drv.h
> > @@ -633,6 +633,10 @@ struct i915_fbc {
> >  	} no_fbc_reason;
> >  };
> >  
> > +struct i915_drrs {
> > +	struct intel_connector *connector;
> > +};
> > +
> >  struct i915_psr {
> >  	bool sink_support;
> >  	bool source_ok;
> > @@ -1320,6 +1324,7 @@ struct drm_i915_private {
> >  	struct timer_list hotplug_reenable_timer;
> >  
> >  	struct i915_fbc fbc;
> > +	struct i915_drrs drrs;
> >  	struct intel_opregion opregion;
> >  	struct intel_vbt_data vbt;
> >  
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index 2315366..d6dddc2 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -3346,6 +3346,7 @@ enum punit_power_well {
> >  #define   PIPECONF_INTERLACED_DBL_ILK		(4 << 21) /* ilk/snb only */
> >  #define   PIPECONF_PFIT_PF_INTERLACED_DBL_ILK	(5 << 21) /* ilk/snb only */
> >  #define   PIPECONF_INTERLACE_MODE_MASK		(7 << 21)
> > +#define   PIPECONF_EDP_RR_MODE_SWITCH		(1 << 20)
> >  #define   PIPECONF_CXSR_DOWNCLOCK	(1<<16)
> >  #define   PIPECONF_COLOR_RANGE_SELECT	(1 << 13)
> >  #define   PIPECONF_BPC_MASK	(0x7 << 5)
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index 517a8cc..b50b170 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -737,6 +737,20 @@ intel_dp_set_clock(struct intel_encoder *encoder,
> >  	}
> >  }
> >  
> > +static void
> > +intel_dp_set_m2_n2(struct intel_crtc *crtc, struct intel_link_m_n *m_n)
> > +{
> > +	struct drm_device *dev = crtc->base.dev;
> > +	struct drm_i915_private *dev_priv = dev->dev_private;
> > +	enum transcoder transcoder = crtc->config.cpu_transcoder;
> > +
> > +	I915_WRITE(PIPE_DATA_M2(transcoder),
> > +		TU_SIZE(m_n->tu) | m_n->gmch_m);
> > +	I915_WRITE(PIPE_DATA_N2(transcoder), m_n->gmch_n);
> > +	I915_WRITE(PIPE_LINK_M2(transcoder), m_n->link_m);
> > +	I915_WRITE(PIPE_LINK_N2(transcoder), m_n->link_n);
> > +}
> > +
> >  bool
> >  intel_dp_compute_config(struct intel_encoder *encoder,
> >  			struct intel_crtc_config *pipe_config)
> > @@ -841,6 +855,14 @@ found:
> >  			       pipe_config->port_clock,
> >  			       &pipe_config->dp_m_n);
> >  
> > +	if (intel_connector->panel.downclock_mode != NULL &&
> > +		intel_dp->drrs_state.type == SEAMLESS_DRRS_SUPPORT) {
> > +			intel_link_compute_m_n(bpp, lane_count,
> > +				intel_connector->panel.downclock_mode->clock,
> > +				pipe_config->port_clock,
> > +				&pipe_config->dp_m2_n2);
> > +	}
> > +
> >  	intel_dp_set_clock(encoder, pipe_config, intel_dp->link_bw);
> >  
> >  	return true;
> > @@ -3632,6 +3654,90 @@ intel_dp_init_panel_power_sequencer_registers(struct drm_device *dev,
> >  		      I915_READ(pp_div_reg));
> >  }
> >  
> > +void intel_dp_set_drrs_state(struct drm_device *dev, int refresh_rate)
> > +{
> > +	struct drm_i915_private *dev_priv = dev->dev_private;
> > +	struct intel_encoder *encoder;
> > +	struct intel_dp *intel_dp = NULL;
> > +	struct intel_crtc_config *config = NULL;
> > +	struct intel_crtc *intel_crtc = NULL;
> > +	struct intel_connector *intel_connector = dev_priv->drrs.connector;
> > +	u32 reg, val;
> > +	enum edp_drrs_refresh_rate_type index = DRRS_HIGH_RR;
> > +
> > +	if (refresh_rate <= 0) {
> > +		DRM_DEBUG_KMS("Refresh rate should be positive non-zero.\n");
> > +		return;
> > +	}
> > +
> > +	if (intel_connector == NULL) {
> > +		DRM_DEBUG_KMS("DRRS supported for eDP only.\n");
> > +		return;
> > +	}
> > +
> > +	if (INTEL_INFO(dev)->gen < 8 && intel_edp_is_psr_enabled(dev)) {
> > +		DRM_DEBUG_KMS("DRRS is disabled as PSR is enabled\n");
> > +		return;
> > +	}
> > +
> > +	encoder = intel_attached_encoder(&intel_connector->base);
> > +	intel_dp = enc_to_intel_dp(&encoder->base);
> > +	intel_crtc = encoder->new_crtc;
> > +
> > +	if (!intel_crtc) {
> > +		DRM_DEBUG_KMS("DRRS: intel_crtc not initialized\n");
> > +		return;
> > +	}
> > +
> > +	config = &intel_crtc->config;
> > +
> > +	if (intel_dp->drrs_state.type < SEAMLESS_DRRS_SUPPORT) {
> > +		DRM_DEBUG_KMS("Only Seamless DRRS supported.\n");
> > +		return;
> > +	}
> > +
> > +	if (intel_connector->panel.downclock_mode->vrefresh == refresh_rate)
> > +		index = DRRS_LOW_RR;
> > +
> > +	if (index == intel_dp->drrs_state.refresh_rate_type) {
> > +		DRM_DEBUG_KMS(
> > +			"DRRS requested for previously set RR...ignoring\n");
> > +		return;
> > +	}
> > +
> > +	if (!intel_crtc->active) {
> > +		DRM_DEBUG_KMS("eDP encoder disabled. CRTC not Active\n");
> > +		return;
> > +	}
> > +
> > +	if (INTEL_INFO(dev)->gen > 6 && INTEL_INFO(dev)->gen < 8) {
> > +		reg = PIPECONF(intel_crtc->config.cpu_transcoder);
> > +		val = I915_READ(reg);
> > +		if (index > DRRS_HIGH_RR) {
> > +			val |= PIPECONF_EDP_RR_MODE_SWITCH;
> > +			intel_dp_set_m2_n2(intel_crtc, &config->dp_m2_n2);
> > +		} else {
> > +			val &= ~PIPECONF_EDP_RR_MODE_SWITCH;
> > +		}
> > +		I915_WRITE(reg, val);
> > +	}
> > +
> > +	/*
> > +	 * mutex taken to ensure that there is no race between differnt
> > +	 * drrs calls trying to update refresh rate. This scenario may occur
> > +	 * in future when idleness detection based DRRS in kernel and
> > +	 * possible calls from user space to set differnt RR are made.
> > +	 */
> > +
> > +	mutex_lock(&intel_dp->drrs_state.mutex);
> > +
> > +	intel_dp->drrs_state.refresh_rate_type = index;
> > +
> > +	mutex_unlock(&intel_dp->drrs_state.mutex);
> > +
> > +	DRM_DEBUG_KMS("eDP Refresh Rate set to : %dHz\n", refresh_rate);
> > +}
> > +
> >  static struct drm_display_mode *
> >  intel_dp_drrs_init(struct intel_digital_port *intel_dig_port,
> >  			struct intel_connector *intel_connector,
> > @@ -3661,6 +3767,10 @@ intel_dp_drrs_init(struct intel_digital_port *intel_dig_port,
> >  		return NULL;
> >  	}
> >  
> > +	dev_priv->drrs.connector = intel_connector;
> > +
> > +	mutex_init(&intel_dp->drrs_state.mutex);
> > +
> >  	intel_dp->drrs_state.type = dev_priv->vbt.drrs_type;
> >  
> >  	intel_dp->drrs_state.refresh_rate_type = DRRS_HIGH_RR;
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index 286d4fb..37d56e5 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -305,6 +305,9 @@ struct intel_crtc_config {
> >  	int pipe_bpp;
> >  	struct intel_link_m_n dp_m_n;
> >  
> > +	/* m2_n2 for eDP downclock */
> > +	struct intel_link_m_n dp_m2_n2;
> > +
> >  	/*
> >  	 * Frequence the dpll for the port should run at. Differs from the
> >  	 * adjusted dotclock e.g. for DP or 12bpc hdmi mode. This is also
> > @@ -534,6 +537,7 @@ struct intel_dp {
> >  	struct {
> >  		enum drrs_support_type type;
> >  		enum edp_drrs_refresh_rate_type refresh_rate_type;
> > +		struct mutex mutex;
> >  	} drrs_state;
> >  
> >  };
> > @@ -789,7 +793,7 @@ void intel_edp_panel_off(struct intel_dp *intel_dp);
> >  void intel_edp_psr_enable(struct intel_dp *intel_dp);
> >  void intel_edp_psr_disable(struct intel_dp *intel_dp);
> >  void intel_edp_psr_update(struct drm_device *dev);
> > -
> > +void intel_dp_set_drrs_state(struct drm_device *dev, int refresh_rate);
> >  
> >  /* intel_dsi.c */
> >  bool intel_dsi_init(struct drm_device *dev);
> > -- 
> > 1.9.1
> >
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch



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