Re: [PATCH 4/8] drm/i915: DRRS calls based on frontbuffer

["Kannan, Vandana" <vandana.kannan@intel.com>]

On 15-Dec-14 3:27 PM, Daniel Vetter wrote:
> On Thu, Dec 11, 2014 at 02:22:53AM +0530, Vandana Kannan wrote:
>> Calls have been added to invalidate/flush DRRS whenever invalidate/flush is
>> called as part of frontbuffer tracking.
>> Apart from calls as a result of GEM tracking to fb invalidate/flush, a
>> call has been added to invalidate fb obj from crtc_page_flip as well. This
>> is to track busyness through flip calls.
>
> That shouldn't be required really. Or maybe I misunderstand what you mean
> here ...
>
Last month when I was implementing this, DRRS worked as expected only 
when this call was made from crtc_page_flip. I checked the recent code 
today and as you mentioned above, this call isn't required.
I can remove this call from this patch..
Having said that, sometime back I observed that Android used 
crtc_page_flip and its possible that DRRS would break in that scenario 
without this call to invalidate..
- Vandana

>> The call to fb_obj_invalidate (in flip) is placed before queuing flip for this
>> obj.
>>
>> drrs_invalidate() and drrs_flush() check for drrs.dp which would be NULL if
>> it was setup in drrs_enable(). This covers for the condition when DRRS is
>> not supported.
>>
>> Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
>> ---
>>   drivers/gpu/drm/i915/intel_display.c     |  8 +++--
>>   drivers/gpu/drm/i915/intel_dp.c          | 51 ++++++++++++++++++++++++++++++++
>>   drivers/gpu/drm/i915/intel_drv.h         |  3 ++
>>   drivers/gpu/drm/i915/intel_frontbuffer.c |  2 ++
>>   4 files changed, 61 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index a9bdc12..a4a565c 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -9717,6 +9717,11 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>>   	if (ret)
>>   		goto cleanup_pending;
>>
>> +	i915_gem_track_fb(work->old_fb_obj, obj,
>> +			  INTEL_FRONTBUFFER_PRIMARY(pipe));
>> +
>> +	intel_fb_obj_invalidate(obj, ring);
>> +
>>   	work->gtt_offset =
>>   		i915_gem_obj_ggtt_offset(obj) + intel_crtc->dspaddr_offset;
>>
>> @@ -9741,9 +9746,6 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
>>   	work->flip_queued_vblank = drm_vblank_count(dev, intel_crtc->pipe);
>>   	work->enable_stall_check = true;
>>
>> -	i915_gem_track_fb(work->old_fb_obj, obj,
>> -			  INTEL_FRONTBUFFER_PRIMARY(pipe));
>> -
>>   	intel_disable_fbc(dev);
>>   	intel_frontbuffer_flip_prepare(dev, INTEL_FRONTBUFFER_PRIMARY(pipe));
>>   	mutex_unlock(&dev->struct_mutex);
>
> This hunk here looks spurious. Or is it relate to what you mention in the
> commit message? Please explain more in-depth.
>
>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>> index 7098470..bc17900 100644
>> --- a/drivers/gpu/drm/i915/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>> @@ -4902,6 +4902,57 @@ unlock:
>>   	mutex_unlock(&dev_priv->drrs.mutex);
>>   }
>>
>> +void intel_edp_drrs_invalidate(struct drm_device *dev,
>> +		unsigned frontbuffer_bits)
>> +{
>> +	struct drm_i915_private *dev_priv = dev->dev_private;
>> +	struct drm_crtc *crtc;
>> +	enum pipe pipe;
>> +
>> +	if (!dev_priv->drrs.dp)
>> +		return;
>> +
>> +	mutex_lock(&dev_priv->drrs.mutex);
>> +	crtc = dp_to_dig_port(dev_priv->drrs.dp)->base.base.crtc;
>> +	pipe = to_intel_crtc(crtc)->pipe;
>> +
>> +	if (dev_priv->drrs.refresh_rate_type == DRRS_LOW_RR) {
>> +		cancel_delayed_work_sync(&dev_priv->drrs.work);
>> +		intel_dp_set_drrs_state(dev_priv->dev,
>> +				dev_priv->drrs.dp->attached_connector->panel.
>> +				fixed_mode->vrefresh);
>> +	}
>> +
>> +	frontbuffer_bits &= INTEL_FRONTBUFFER_ALL_MASK(pipe);
>> +
>> +	dev_priv->drrs.busy_frontbuffer_bits |= frontbuffer_bits;
>> +	mutex_unlock(&dev_priv->drrs.mutex);
>> +}
>> +
>> +void intel_edp_drrs_flush(struct drm_device *dev,
>> +		unsigned frontbuffer_bits)
>> +{
>> +	struct drm_i915_private *dev_priv = dev->dev_private;
>> +	struct drm_crtc *crtc;
>> +	enum pipe pipe;
>> +
>> +	if (!dev_priv->drrs.dp)
>> +		return;
>> +
>> +	mutex_lock(&dev_priv->drrs.mutex);
>> +	crtc = dp_to_dig_port(dev_priv->drrs.dp)->base.base.crtc;
>> +	pipe = to_intel_crtc(crtc)->pipe;
>> +	dev_priv->drrs.busy_frontbuffer_bits &= ~frontbuffer_bits;
>> +
>> +	cancel_delayed_work_sync(&dev_priv->drrs.work);
>> +
>> +	if (dev_priv->drrs.refresh_rate_type != DRRS_LOW_RR &&
>> +			!dev_priv->drrs.busy_frontbuffer_bits)
>> +		schedule_delayed_work(&dev_priv->drrs.work,
>> +				msecs_to_jiffies(1000));
>
> With mod_delayed_work you can avoid the cancel_work. Also sync will
> probably deadlock.
> -Daniel
>
>> +	mutex_unlock(&dev_priv->drrs.mutex);
>> +}
>> +
>>   static struct drm_display_mode *
>>   intel_dp_drrs_init(struct intel_connector *intel_connector,
>>   		struct drm_display_mode *fixed_mode)
>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>> index 1c3c25a..763c097 100644
>> --- a/drivers/gpu/drm/i915/intel_drv.h
>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> @@ -1004,6 +1004,9 @@ int intel_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
>>   int intel_disable_plane(struct drm_plane *plane);
>>   void intel_edp_drrs_enable(struct intel_dp *intel_dp);
>>   void intel_edp_drrs_disable(struct intel_dp *intel_dp);
>> +void intel_edp_drrs_invalidate(struct drm_device *dev,
>> +		unsigned frontbuffer_bits);
>> +void intel_edp_drrs_flush(struct drm_device *dev, unsigned frontbuffer_bits);
>>
>>   /* intel_dp_mst.c */
>>   int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id);
>> diff --git a/drivers/gpu/drm/i915/intel_frontbuffer.c b/drivers/gpu/drm/i915/intel_frontbuffer.c
>> index 79f6d72..73cb6e0 100644
>> --- a/drivers/gpu/drm/i915/intel_frontbuffer.c
>> +++ b/drivers/gpu/drm/i915/intel_frontbuffer.c
>> @@ -157,6 +157,7 @@ void intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
>>   	intel_mark_fb_busy(dev, obj->frontbuffer_bits, ring);
>>
>>   	intel_psr_invalidate(dev, obj->frontbuffer_bits);
>> +	intel_edp_drrs_invalidate(dev, obj->frontbuffer_bits);
>>   }
>>
>>   /**
>> @@ -182,6 +183,7 @@ void intel_frontbuffer_flush(struct drm_device *dev,
>>
>>   	intel_mark_fb_busy(dev, frontbuffer_bits, NULL);
>>
>> +	intel_edp_drrs_flush(dev, frontbuffer_bits);
>>   	intel_psr_flush(dev, frontbuffer_bits);
>>
>>   	/*
>> --
>> 2.0.1
>>
>
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