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

Vandana Kannan vandana.kannan at intel.com
Fri Apr 11 11:18:53 CEST 2014


On Apr-10-2014 2:28 PM, Daniel Vetter wrote:
> 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
> 
Hi Daniel,

Could you please elaborate on your input above - on the missing code and
cross-checking for support part?

-Vandana

>>> ---
>>>  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
> 




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