[Intel-gfx] [PATCH v4 5/5] drm/i915/psr/bdw+: Enable CRC check in the static frame on the sink side

[Souza, Jose]

On Thu, 2018-06-14 at 14:19 -0700, Rodrigo Vivi wrote:
> On Thu, Jun 14, 2018 at 01:34:33PM -0700, José Roberto de Souza
> wrote:
> > Sink can be configured to calculate the CRC over the static frame
> > and
> > compare with the CRC calculated and transmited in the VSC SDP by
> > source, if there is a mismatch sink will do a short pulse in HPD
> > and set DP_PSR_LINK_CRC_ERROR in DP_PSR_ERROR_STATUS.
> > 
> > Spec: 7723
> > 
> > v4:
> > patch moved to after 'drm/i915/psr: Avoid PSR exit max time
> > timeout'
> > to avoid touch in 2 patches EDP_PSR_DEBUG.
> > 
> > v3:
> > disabling PSR instead of exiting on error
> > 
> > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_reg.h  |  1 +
> >  drivers/gpu/drm/i915/intel_psr.c | 16 ++++++++++++----
> >  2 files changed, 13 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > b/drivers/gpu/drm/i915/i915_reg.h
> > index 140f6a27d696..ed34ccd81c7c 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -4038,6 +4038,7 @@ enum {
> >  #define   EDP_PSR_SKIP_AUX_EXIT			(1<<12)
> >  #define   EDP_PSR_TP1_TP2_SEL			(0<<11)
> >  #define   EDP_PSR_TP1_TP3_SEL			(1<<11)
> > +#define   EDP_PSR_CRC_ENABLE			(1<<10) /*
> > BDW+ */
> >  #define   EDP_PSR_TP2_TP3_TIME_500us		(0<<8)
> >  #define   EDP_PSR_TP2_TP3_TIME_100us		(1<<8)
> >  #define   EDP_PSR_TP2_TP3_TIME_2500us		(2<<8)
> > diff --git a/drivers/gpu/drm/i915/intel_psr.c
> > b/drivers/gpu/drm/i915/intel_psr.c
> > index 177cd57b1029..cf72b79caf3f 100644
> > --- a/drivers/gpu/drm/i915/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/intel_psr.c
> > @@ -360,6 +360,8 @@ static void hsw_psr_enable_sink(struct intel_dp
> > *intel_dp)
> >  
> >  	if (dev_priv->psr.link_standby)
> >  		dpcd_val |= DP_PSR_MAIN_LINK_ACTIVE;
> > +	if (!dev_priv->psr.psr2_enabled && INTEL_GEN(dev_priv) >=
> > 8)
> > +		dpcd_val |= DP_PSR_CRC_VERIFICATION;
> >  	drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_EN_CFG,
> > dpcd_val);
> >  
> >  	drm_dp_dpcd_writeb(&intel_dp->aux, DP_SET_POWER,
> > DP_SET_POWER_D0);
> > @@ -415,6 +417,9 @@ static void hsw_activate_psr1(struct intel_dp
> > *intel_dp)
> >  	else
> >  		val |= EDP_PSR_TP1_TP2_SEL;
> >  
> > +	if (INTEL_GEN(dev_priv) >= 8)
> > +		val |= EDP_PSR_CRC_ENABLE;
> > +
> >  	val |= I915_READ(EDP_PSR_CTL) &
> > EDP_PSR_RESTORE_PSR_ACTIVE_CTX_MASK;
> >  	I915_WRITE(EDP_PSR_CTL, val);
> >  }
> > @@ -1032,16 +1037,19 @@ void intel_psr_short_pulse(struct intel_dp
> > *intel_dp)
> >  		goto exit;
> >  	}
> >  
> > -	if (val & DP_PSR_RFB_STORAGE_ERROR) {
> > -		DRM_DEBUG_KMS("PSR RFB storage error, exiting
> > PSR\n");
> > +	if (val & (DP_PSR_RFB_STORAGE_ERROR |
> > DP_PSR_LINK_CRC_ERROR)) {
> > +		if (val & DP_PSR_RFB_STORAGE_ERROR)
> 
> I believe we can avoid the duplication of the conditions here...
> maybe with:
> if (val & DP_PSR_RFB_STORAGE_ERROR)
> //msg
> else if (val & DP_PSR_LINK_CRC_ERROR)
> //msg
> else
> goto clear

Well val can have all 3 errors set, so it would only print the first
debug message but I got your point, I will change to:

if (val & DP_PSR_RFB_STORAGE_ERROR)
//msg
if (val & DP_PSR_LINK_CRC_ERROR)
//msg
...

if (val)
	intel_psr_disable_locked()

as right all errors are unrecovered. This sounds good?


> 
> intel_psr_disable_locked()
> 
> > +			DRM_DEBUG_KMS("PSR RFB storage error,
> > disabling PSR\n");
> > +		if (val & DP_PSR_LINK_CRC_ERROR)
> > +			DRM_DEBUG_KMS("PSR Link CRC error,
> > disabling PSR\n");
> >  		psr_disable(intel_dp);
> >  	}
> > -	if (val & (DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR |
> > DP_PSR_LINK_CRC_ERROR))
> > +	if (val & DP_PSR_VSC_SDP_UNCORRECTABLE_ERROR)
> >  		DRM_ERROR("PSR_ERROR_STATUS not handled %x\n",
> > val);
> 
> clear:
> >  	/* clear status register */
> >  	drm_dp_dpcd_writeb(&intel_dp->aux, DP_PSR_ERROR_STATUS,
> > val);
> >  
> > -	/* TODO: handle other PSR/PSR2 errors */
> > +	/* TODO: handle PSR2 errors */
> >  exit:
> >  	mutex_unlock(&psr->lock);
> >  }
> > -- 
> > 2.17.1
> >