[Intel-gfx] [PATCH] drm/i915/psr: Split sink status into a separate debugfs node

[Dhinakaran Pandiyan]

On Thursday, July 5, 2018 2:04:18 PM PDT Rodrigo Vivi wrote:
> On Wed, Jul 04, 2018 at 05:31:21PM -0700, Dhinakaran Pandiyan wrote:
> > This allows to read i915_edp_psr_status from tests without triggering
> > any AUX communication. Take this opportunity to move this under the
> > eDP-1 connector directory as the status we print is of the sink.
> > 
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Cc: José Roberto de Souza <jose.souza at intel.com>
> > Suggested-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > ---
> > 
> >  drivers/gpu/drm/i915/i915_debugfs.c | 69
> >  +++++++++++++++++++++---------------- 1 file changed, 39 insertions(+),
> >  30 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> > b/drivers/gpu/drm/i915/i915_debugfs.c index f6142d78ede4..5069d5dedafe
> > 100644
> > --- a/drivers/gpu/drm/i915/i915_debugfs.c
> > +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> > @@ -2592,6 +2592,41 @@ static const struct file_operations
> > i915_guc_log_relay_fops = {> 
> >  	.release = i915_guc_log_relay_release,
> >  
> >  };
> > 
> > +static int i915_psr_sink_status_show(struct seq_file *m, void *data)
> > +{
> > +	u8 val;
> > +	static const char * const sink_status[] = {
> > +		"inactive",
> > +		"transition to active, capture and display",
> > +		"active, display from RFB",
> > +		"active, capture and display on sink device timings",
> > +		"transition to inactive, capture and display, timing re-sync",
> > +		"reserved",
> > +		"reserved",
> > +		"sink internal error",
> > +	};
> > +	struct drm_connector *connector = m->private;
> > +	struct intel_dp *intel_dp =
> > +		enc_to_intel_dp(&intel_attached_encoder(connector)->base);
> > +
> > +	if (connector->status != connector_status_connected)
> > +		return -ENODEV;
> > +
> > +	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PSR_STATUS, &val) == 1) {
> > +		const char *str = "unknown";
> > +
> > +		val &= DP_PSR_SINK_STATE_MASK;
> > +		if (val < ARRAY_SIZE(sink_status))
> > +			str = sink_status[val];
> > +		seq_printf(m, "Sink PSR status: 0x%x [%s]\n", val, str);
> > +	} else {
> > +		DRM_ERROR("dpcd read (at %u) failed\n", DP_PSR_STATUS);
> > +	}
> > +
> > +	return 0;
> > +}
> > +DEFINE_SHOW_ATTRIBUTE(i915_psr_sink_status);
> > +
> > 
> >  static void
> >  psr_source_status(struct drm_i915_private *dev_priv, struct seq_file *m)
> >  {
> > 
> > @@ -2643,26 +2678,6 @@ psr_source_status(struct drm_i915_private
> > *dev_priv, struct seq_file *m)> 
> >  	seq_printf(m, "Source PSR status: 0x%x [%s]\n", psr_status, 
"unknown");
> >  
> >  }
> > 
> > -static const char *psr_sink_status(u8 val)
> > -{
> > -	static const char * const sink_status[] = {
> > -		"inactive",
> > -		"transition to active, capture and display",
> > -		"active, display from RFB",
> > -		"active, capture and display on sink device timings",
> > -		"transition to inactive, capture and display, timing re-sync",
> > -		"reserved",
> > -		"reserved",
> > -		"sink internal error"
> > -	};
> > -
> > -	val &= DP_PSR_SINK_STATE_MASK;
> > -	if (val < ARRAY_SIZE(sink_status))
> > -		return sink_status[val];
> > -
> > -	return "unknown";
> > -}
> > -
> > 
> >  static int i915_edp_psr_status(struct seq_file *m, void *data)
> >  {
> >  
> >  	struct drm_i915_private *dev_priv = node_to_i915(m->private);
> > 
> > @@ -2706,15 +2721,6 @@ static int i915_edp_psr_status(struct seq_file *m,
> > void *data)> 
> >  	}
> >  	
> >  	psr_source_status(dev_priv, m);
> > 
> > -
> > -	if (dev_priv->psr.enabled) {
> > -		struct drm_dp_aux *aux = &dev_priv->psr.enabled->aux;
> > -		u8 val;
> > -
> > -		if (drm_dp_dpcd_readb(aux, DP_PSR_STATUS, &val) == 1)
> > -			seq_printf(m, "Sink PSR status: 0x%x [%s]\n", val,
> > -				   psr_sink_status(val));
> > -	}
> > 
> >  	mutex_unlock(&dev_priv->psr.lock);
> 
> I wonder if we shouldn't get this lock there to make sure taat no
> PSR transition from our driver is getting called.
> 
This lock was useful as we wanted dev_priv->psr.enabled == intel_dp to be 
valid. I don't see why we have to serialize sink DPCD reads w.r.t the driver's 
PSR state transitions.

> >  	if (READ_ONCE(dev_priv->psr.debug)) {
> > 
> > @@ -4971,9 +4977,12 @@ int i915_debugfs_connector_add(struct drm_connector
> > *connector)> 
> >  		debugfs_create_file("i915_dpcd", S_IRUGO, root,
> >  		
> >  				    connector, &i915_dpcd_fops);
> > 
> > -	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP)
> > +	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
> 
> it seems that we should also move the other status file here to this
> block...

Do you mean i915_edp_psr_status? As I see it, that is a feature specific 
debugfs node that includes source information as well. The ones under 
$debugfs/eDP-1/ are all panel related.

> >  		debugfs_create_file("i915_panel_timings", S_IRUGO, root,
> >  		
> >  				    connector, &i915_panel_fops);
> > 
> > +		debugfs_create_file("i915_psr_sink_status", S_IRUGO, root,
> > +				     connector, &i915_psr_sink_status_fops);
> 
> ... and also rename the other 2 entries to be in pair with this new one:
> 
> or all i915_edp_psr or all i915_psr...
> 
I wrote this as i915_psr and realized that it might get confusing since we 
also have i915_edp_psr_status for feature status. And "_edp_" is redundant 
because all the nodes are under the eDP-1 directory.  But, yeah I can change 
it to "i915_psr" if you think that is better.

> > +	}
> > 
> >  	return 0;
> >  
> >  }