diff mbox

[2/5] drm/i915/psr: Use more PSR HW tracking.

Message ID 20180216043322.22874-2-dhinakaran.pandiyan@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dhinakaran Pandiyan Feb. 16, 2018, 4:33 a.m. UTC
From: Rodrigo Vivi <rodrigo.vivi@intel.com>

So far we are using frontbuffer tracking for everything
and ignoring that PSR has a HW capable HW tracking for many
modern usages of GPU on Core platforms and newer Atom ones.

One reason for that is that we were trying to keep same
infrastructure in place for VLV/CHV than the rest of platforms.
But also because when this infrastructure was created
the front-buffer-tracking origin wasn't that good and stable
how it is today after Paulo reworked it to attend FBC cases.

However this PSR implementation without HW tracking died
on gen8LP. And newer platforms are starting to demand more HW
tracking specially with PSR2 cases in mind.

By disabling and re-enabling PSR totally every time we believe
someone is going to change the front buffer content we don't
allow PSR HW tracking to do this job and specially compromising
the whole idea of PSR2 case where the HW tracking detect only
the damaged area and do a partial screen update.

So, from now on, on the platforms that has hw_tracking let's
rely more on HW tracking.

This also is the case in used by other drivers and more validated
by SV teams. So I hope that this will lead us to less misterious
bugs.

v2: Only do this for platform that actually has hw tracking.

v3 from DK
Do this only for flips, small gradual changes are better.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Jim Bride <jim.bride@linux.intel.com>
Cc: Vathsala Nagaraju <vathsala.nagaraju@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h          |  1 +
 drivers/gpu/drm/i915/intel_drv.h         |  3 ++-
 drivers/gpu/drm/i915/intel_frontbuffer.c |  2 +-
 drivers/gpu/drm/i915/intel_psr.c         | 10 +++++++++-
 4 files changed, 13 insertions(+), 3 deletions(-)

Comments

Chris Wilson Feb. 16, 2018, 8:54 a.m. UTC | #1
Quoting Dhinakaran Pandiyan (2018-02-16 04:33:19)
> From: Rodrigo Vivi <rodrigo.vivi@intel.com>
> 
> So far we are using frontbuffer tracking for everything
> and ignoring that PSR has a HW capable HW tracking for many
> modern usages of GPU on Core platforms and newer Atom ones.
> 
> One reason for that is that we were trying to keep same
> infrastructure in place for VLV/CHV than the rest of platforms.
> But also because when this infrastructure was created
> the front-buffer-tracking origin wasn't that good and stable
> how it is today after Paulo reworked it to attend FBC cases.
> 
> However this PSR implementation without HW tracking died
> on gen8LP. And newer platforms are starting to demand more HW
> tracking specially with PSR2 cases in mind.
> 
> By disabling and re-enabling PSR totally every time we believe
> someone is going to change the front buffer content we don't
> allow PSR HW tracking to do this job and specially compromising
> the whole idea of PSR2 case where the HW tracking detect only
> the damaged area and do a partial screen update.
> 
> So, from now on, on the platforms that has hw_tracking let's
> rely more on HW tracking.
> 
> This also is the case in used by other drivers and more validated
> by SV teams. So I hope that this will lead us to less misterious
> bugs.
> 
> v2: Only do this for platform that actually has hw tracking.
> 
> v3 from DK
> Do this only for flips, small gradual changes are better.
> 
> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
> Cc: Jim Bride <jim.bride@linux.intel.com>
> Cc: Vathsala Nagaraju <vathsala.nagaraju@intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h          |  1 +
>  drivers/gpu/drm/i915/intel_drv.h         |  3 ++-
>  drivers/gpu/drm/i915/intel_frontbuffer.c |  2 +-
>  drivers/gpu/drm/i915/intel_psr.c         | 10 +++++++++-
>  4 files changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 90eca42ab2b8..31aae988d515 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -770,6 +770,7 @@ struct i915_psr {
>         bool y_cord_support;
>         bool colorimetry_support;
>         bool alpm;
> +       bool has_hw_tracking;

Time for some bool:1 compaction?

> @@ -841,6 +842,9 @@ void intel_psr_invalidate(struct drm_i915_private *dev_priv,
>         if (!CAN_PSR(dev_priv))
>                 return;
>  
> +       if (dev_priv->psr.has_hw_tracking && origin == ORIGIN_FLIP)
> +               return;
> +
>         mutex_lock(&dev_priv->psr.lock);
>         if (!dev_priv->psr.enabled) {
>                 mutex_unlock(&dev_priv->psr.lock);
> @@ -881,6 +885,9 @@ void intel_psr_flush(struct drm_i915_private *dev_priv,
>         if (!CAN_PSR(dev_priv))
>                 return;
>  
> +       if (dev_priv->psr.has_hw_tracking && origin == ORIGIN_FLIP)
> +               return;
> +

Much easier for the causal reader to understand :)
-Chris
Dhinakaran Pandiyan March 7, 2018, 3:54 a.m. UTC | #2
On Fri, 2018-02-16 at 08:54 +0000, Chris Wilson wrote:
> Quoting Dhinakaran Pandiyan (2018-02-16 04:33:19)

> > From: Rodrigo Vivi <rodrigo.vivi@intel.com>

> > 

> > So far we are using frontbuffer tracking for everything

> > and ignoring that PSR has a HW capable HW tracking for many

> > modern usages of GPU on Core platforms and newer Atom ones.

> > 

> > One reason for that is that we were trying to keep same

> > infrastructure in place for VLV/CHV than the rest of platforms.

> > But also because when this infrastructure was created

> > the front-buffer-tracking origin wasn't that good and stable

> > how it is today after Paulo reworked it to attend FBC cases.

> > 

> > However this PSR implementation without HW tracking died

> > on gen8LP. And newer platforms are starting to demand more HW

> > tracking specially with PSR2 cases in mind.

> > 

> > By disabling and re-enabling PSR totally every time we believe

> > someone is going to change the front buffer content we don't

> > allow PSR HW tracking to do this job and specially compromising

> > the whole idea of PSR2 case where the HW tracking detect only

> > the damaged area and do a partial screen update.

> > 

> > So, from now on, on the platforms that has hw_tracking let's

> > rely more on HW tracking.

> > 

> > This also is the case in used by other drivers and more validated

> > by SV teams. So I hope that this will lead us to less misterious

> > bugs.

> > 

> > v2: Only do this for platform that actually has hw tracking.

> > 

> > v3 from DK

> > Do this only for flips, small gradual changes are better.

> > 

> > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

> > Cc: Jim Bride <jim.bride@linux.intel.com>

> > Cc: Vathsala Nagaraju <vathsala.nagaraju@intel.com>

> > Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

> > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

> > ---

> >  drivers/gpu/drm/i915/i915_drv.h          |  1 +

> >  drivers/gpu/drm/i915/intel_drv.h         |  3 ++-

> >  drivers/gpu/drm/i915/intel_frontbuffer.c |  2 +-

> >  drivers/gpu/drm/i915/intel_psr.c         | 10 +++++++++-

> >  4 files changed, 13 insertions(+), 3 deletions(-)

> > 

> > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h

> > index 90eca42ab2b8..31aae988d515 100644

> > --- a/drivers/gpu/drm/i915/i915_drv.h

> > +++ b/drivers/gpu/drm/i915/i915_drv.h

> > @@ -770,6 +770,7 @@ struct i915_psr {

> >         bool y_cord_support;

> >         bool colorimetry_support;

> >         bool alpm;

> > +       bool has_hw_tracking;

> 

> Time for some bool:1 compaction?


Oddly it increases the binary size, so I didn't make this change in the
new version I sent out -
https://patchwork.freedesktop.org/series/39502/

I also left out
Patch 5/5: The mod_timer patch that Andy sent avoids the problem this
patch works around.
Patch 4/5: frontbuffer flush during prepare_fb() might be necessary to
exit PSR early (before we start updating pipe registers) 


> 

> > @@ -841,6 +842,9 @@ void intel_psr_invalidate(struct drm_i915_private *dev_priv,

> >         if (!CAN_PSR(dev_priv))

> >                 return;

> >  

> > +       if (dev_priv->psr.has_hw_tracking && origin == ORIGIN_FLIP)

> > +               return;

> > +

> >         mutex_lock(&dev_priv->psr.lock);

> >         if (!dev_priv->psr.enabled) {

> >                 mutex_unlock(&dev_priv->psr.lock);

> > @@ -881,6 +885,9 @@ void intel_psr_flush(struct drm_i915_private *dev_priv,

> >         if (!CAN_PSR(dev_priv))

> >                 return;

> >  

> > +       if (dev_priv->psr.has_hw_tracking && origin == ORIGIN_FLIP)

> > +               return;

> > +

> 

> Much easier for the causal reader to understand :)

> -Chris

> _______________________________________________

> Intel-gfx mailing list

> Intel-gfx@lists.freedesktop.org

> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 90eca42ab2b8..31aae988d515 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -770,6 +770,7 @@  struct i915_psr {
 	bool y_cord_support;
 	bool colorimetry_support;
 	bool alpm;
+	bool has_hw_tracking;
 
 	void (*enable_source)(struct intel_dp *,
 			      const struct intel_crtc_state *);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 898064e8bea7..7192045c5149 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1862,7 +1862,8 @@  void intel_psr_enable(struct intel_dp *intel_dp,
 void intel_psr_disable(struct intel_dp *intel_dp,
 		      const struct intel_crtc_state *old_crtc_state);
 void intel_psr_invalidate(struct drm_i915_private *dev_priv,
-			  unsigned frontbuffer_bits);
+			  unsigned frontbuffer_bits,
+			  enum fb_op_origin origin);
 void intel_psr_flush(struct drm_i915_private *dev_priv,
 		     unsigned frontbuffer_bits,
 		     enum fb_op_origin origin);
diff --git a/drivers/gpu/drm/i915/intel_frontbuffer.c b/drivers/gpu/drm/i915/intel_frontbuffer.c
index fcfc217e754e..efda1af9a5b3 100644
--- a/drivers/gpu/drm/i915/intel_frontbuffer.c
+++ b/drivers/gpu/drm/i915/intel_frontbuffer.c
@@ -79,7 +79,7 @@  void __intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
 		spin_unlock(&dev_priv->fb_tracking.lock);
 	}
 
-	intel_psr_invalidate(dev_priv, frontbuffer_bits);
+	intel_psr_invalidate(dev_priv, frontbuffer_bits, origin);
 	intel_edp_drrs_invalidate(dev_priv, frontbuffer_bits);
 	intel_fbc_invalidate(dev_priv, frontbuffer_bits, origin);
 }
diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index 2ef374f936b9..2a31c7cbdb41 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -824,6 +824,7 @@  void intel_psr_single_frame_update(struct drm_i915_private *dev_priv,
  * intel_psr_invalidate - Invalidade PSR
  * @dev_priv: i915 device
  * @frontbuffer_bits: frontbuffer plane tracking bits
+ * @origin: which operation caused the invalidate
  *
  * Since the hardware frontbuffer tracking has gaps we need to integrate
  * with the software frontbuffer tracking. This function gets called every
@@ -833,7 +834,7 @@  void intel_psr_single_frame_update(struct drm_i915_private *dev_priv,
  * Dirty frontbuffers relevant to PSR are tracked in busy_frontbuffer_bits."
  */
 void intel_psr_invalidate(struct drm_i915_private *dev_priv,
-			  unsigned frontbuffer_bits)
+			  unsigned frontbuffer_bits, enum fb_op_origin origin)
 {
 	struct drm_crtc *crtc;
 	enum pipe pipe;
@@ -841,6 +842,9 @@  void intel_psr_invalidate(struct drm_i915_private *dev_priv,
 	if (!CAN_PSR(dev_priv))
 		return;
 
+	if (dev_priv->psr.has_hw_tracking && origin == ORIGIN_FLIP)
+		return;
+
 	mutex_lock(&dev_priv->psr.lock);
 	if (!dev_priv->psr.enabled) {
 		mutex_unlock(&dev_priv->psr.lock);
@@ -881,6 +885,9 @@  void intel_psr_flush(struct drm_i915_private *dev_priv,
 	if (!CAN_PSR(dev_priv))
 		return;
 
+	if (dev_priv->psr.has_hw_tracking && origin == ORIGIN_FLIP)
+		return;
+
 	mutex_lock(&dev_priv->psr.lock);
 	if (!dev_priv->psr.enabled) {
 		mutex_unlock(&dev_priv->psr.lock);
@@ -957,6 +964,7 @@  void intel_psr_init(struct drm_i915_private *dev_priv)
 		dev_priv->psr.activate = vlv_psr_activate;
 		dev_priv->psr.setup_vsc = vlv_psr_setup_vsc;
 	} else {
+		dev_priv->psr.has_hw_tracking = true;
 		dev_priv->psr.enable_source = hsw_psr_enable_source;
 		dev_priv->psr.disable_source = hsw_psr_disable;
 		dev_priv->psr.enable_sink = hsw_psr_enable_sink;