[Intel-gfx] [PATCH] drm/i915/psr: Enable PSR1 by default on gen9+ platforms

[Dhinakaran Pandiyan]

On Wed, 2018-07-25 at 09:12 -0700, Rodrigo Vivi wrote:
> On Wed, Jul 25, 2018 at 12:22:28AM -0700, Dhinakaran Pandiyan wrote:
> > 
> > We have merged several fixes, re-written some tests and improved
> > debug
> > capability in the past several months, so this is a good time to
> > give PSR1
> > another try. PSR1 has not been tested on HSW and BDW recently, so
> > let's
> > enable only on gen9+ now.
> > 
> > Cc: Rodigo Vivi <rodrigo.vivi at intel.com>
> > Cc: José Roberto de Souza <jose.souza at intel.com>
> > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_psr.c | 20 ++++++++++----------
> >  1 file changed, 10 insertions(+), 10 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_psr.c
> > b/drivers/gpu/drm/i915/intel_psr.c
> > index 4bd5768731ee..942db85da6a1 100644
> > --- a/drivers/gpu/drm/i915/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/intel_psr.c
> > @@ -471,10 +471,8 @@ void intel_psr_compute_config(struct intel_dp
> > *intel_dp,
> >  	if (!CAN_PSR(dev_priv))
> >  		return;
> >  
> > -	if (!i915_modparams.enable_psr) {
> > -		DRM_DEBUG_KMS("PSR disable by flag\n");
> Why are you removing the message?
> I think it is still useful... and enable_psr == -1 doesn't trigger
> that.
> 
The text was a bit vague to start with, and is confusing when combined
with this patch. Agreed, it is useful to have a debug message, I'll
replace it.

> > 
> > +	if (!i915_modparams.enable_psr)
> >  		return;
> > -	}
> >  
> >  	/*
> >  	 * HSW spec explicitly says PSR is tied to port A.
> > @@ -516,7 +514,11 @@ void intel_psr_compute_config(struct intel_dp
> > *intel_dp,
> >  	}
> >  
> >  	crtc_state->has_psr = true;
> > -	crtc_state->has_psr2 = intel_psr2_config_valid(intel_dp,
> > crtc_state);
> > +
> > +	/* Enable only PSR 1 by default for now */
> > +	crtc_state->has_psr2 = i915_modparams.enable_psr == 1 &&
> > +			       intel_psr2_config_valid(intel_dp,
> > crtc_state);
> > +
> this might get confusing...
> -1 - enable psr1
> 0 - disable
> 1 - enable psr2
> 
> and far from the variable... Well... I want to kill the parameter
> anyways
> so no hard feelings on having this here, but what about some debug
> messages
> at least?
> 
> /* Enable only PSR1 by default for now */
> if (i915_modparams.enable_psr == -1) {
> 	DRM_DEBUG_KMS("Avoiding PSR2 by platform default")
> 	crtc_state->has_psr2 = 0;
> } else {
> 	crtc_state->has_psr2 = intel_psr2_config_valid(intel_dp,
> crtc_state);
> }
> 

The reason I added a check for i915.enable_psr==1 was to enable PSR2
only when the user passes the exact value. Otherwise, we should fall
back to default.

> > 
> >  	DRM_DEBUG_KMS("Enabling PSR%s\n", crtc_state->has_psr2 ?
> > "2" : "");
> >  }
> >  
> > @@ -956,12 +958,10 @@ void intel_psr_init(struct drm_i915_private
> > *dev_priv)
> >  	if (!dev_priv->psr.sink_support)
> >  		return;
> >  
> > -	if (i915_modparams.enable_psr == -1) {
> > -		i915_modparams.enable_psr = dev_priv-
> > >vbt.psr.enable;
> > -
> > -		/* Per platform default: all disabled. */
> > -		i915_modparams.enable_psr = 0;
> > -	}
> > +	/* Enable PSR 1 default only on gen9+ */
> > +	if (i915_modparams.enable_psr == -1)
> > +		if (INTEL_GEN(dev_priv) < 9 || !dev_priv-
> > >vbt.psr.enable)
> > +			i915_modparams.enable_psr = 0;
> we talked about this in person, but just for the record:
> we need to check cnl and icl on CI for psr cases before make this >
> 9.

The failures on ICL are due to an unrelated debug warning. The CNL ones
are interesting, most likely due to us enabling PSR2 by setting the
module parameter=1 from the IGTs. But, it still should not be failing,
I'll check.



> 
> > 
> > 
> >  	/* Set link_standby x link_off defaults */
> >  	if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))