[Intel-gfx] [PATCH] drm/i915: Fix psr sink status report.

[Dhinakaran Pandiyan]

On Fri, 2018-07-20 at 10:38 -0700, Rodrigo Vivi wrote:
> On Thu, Jul 19, 2018 at 06:52:00PM -0700, Dhinakaran Pandiyan wrote:
> > 
> > On Thu, 2018-07-19 at 17:31 -0700, Rodrigo Vivi wrote:
> > > 
> > > First of all don't try to read dpcd if PSR is not even supported.
> > > 
> > > But also, if read failed return -EIO instead of reporting via a
> > > backchannel.
> > > 
> > > v2: fix dev_priv: At this level m->private is the connector.
> > > (CI/DK)
> > >     don't convert dpcd read errors to EIO. (DK)
> > > 
> > > Fixes: 5b7b30864d1d ("drm/i915/psr: Split sink status into a
> > > separate
> > > debugfs node")
> > > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> > > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > > Cc: José Roberto de Souza <jose.souza at intel.com>
> > > Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/i915_debugfs.c | 13 +++++++++++--
> > >  1 file changed, 11 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> > > b/drivers/gpu/drm/i915/i915_debugfs.c
> > > index b3aefd623557..59dc0610ea44 100644
> > > --- a/drivers/gpu/drm/i915/i915_debugfs.c
> > > +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> > > @@ -2606,13 +2606,22 @@ static int
> > > i915_psr_sink_status_show(struct
> > > seq_file *m, void *data)
> > >  		"sink internal error",
> > >  	};
> > >  	struct drm_connector *connector = m->private;
> > > +	struct drm_i915_private *dev_priv = to_i915(connector-
> > > >dev);
> > >  	struct intel_dp *intel_dp =
> > >  		enc_to_intel_dp(&intel_attached_encoder(connecto
> > > r)-
> > > > 
> > > > base);
> > > +	int ret;
> > > +
> > > +	if (!CAN_PSR(dev_priv)) {
> > > +		seq_puts(m, "PSR Unsupported\n");
> > > +		return -ENODEV;
> > > +	}
> > >  
> > >  	if (connector->status != connector_status_connected)
> > >  		return -ENODEV;
> > >  
> > > -	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PSR_STATUS,
> > > &val)
> > > == 1) {
> > > +	ret = drm_dp_dpcd_readb(&intel_dp->aux, DP_PSR_STATUS,
> > > &val);
> > > +
> > > +	if (ret == 1) {
> > >  		const char *str = "unknown";
> > >  
> > >  		val &= DP_PSR_SINK_STATE_MASK;
> > > @@ -2620,7 +2629,7 @@ static int i915_psr_sink_status_show(struct
> > > seq_file *m, void *data)
> > >  			str = sink_status[val];
> > >  		seq_printf(m, "Sink PSR status: 0x%x [%s]\n",
> > > val,
> > > str);
> > >  	} else {
> > dpcd_readb() is not expected to return anything other than 1 or a
> > negative error code, so this looks good.
> > Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> thanks, pushed.
> 
> > 
> > 
> > 
> > Are you also sending a similar fix for i915_dpcd_show()? That
> > function
> > also prints a DRM_ERROR() for failed aux transactions.
> well... it is a bit different there because we cannot return in the
> middle
> of the loop because we might want to get other regs read. but
> probably it
> is a good idea to print the error message along with the reads so you
> don't
> have to look to 2 places.
> 
> I will put a simple patch and we can wait until Jani is back from
> vacation since he was the author there.

Okay.

> 
> > 
> > 
> > > 
> > > -		DRM_ERROR("dpcd read (at %u) failed\n",
> > > DP_PSR_STATUS);
> > > +		return ret;
> > >  	}
> > >  
> > >  	return 0;