Re: [Intel-gfx] [PATCH v6 2/2] drm/i915/display/vrr: Reset VRR capable property on a long hpd

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Tue, Mar 01, 2022 at 11:30:52AM -0800, Navare, Manasi wrote:
> Hi Ville,
> 
> Does it make sense to add the set prop in intel_dp_Set_edid but keep the reset to false
> in intel_dp_detect where we clear other parameters?

We don't clear stuff in .detect(), or at least shouldn't. .detect() doesn't
even get run when forcing the connector status.

> 
> Manasi
> 
> 
> On Fri, Feb 25, 2022 at 05:11:02PM -0800, Navare, Manasi wrote:
> > On Fri, Feb 25, 2022 at 11:13:35AM +0200, Ville Syrjälä wrote:
> > > On Thu, Feb 24, 2022 at 05:30:55PM -0800, Manasi Navare wrote:
> > > > With some VRR panels, user can turn VRR ON/OFF on the fly from the panel settings.
> > > > When VRR is turned OFF ,sends a long HPD to the driver clearing the Ignore MSA bit
> > > > in the DPCD. Currently the driver parses that onevery HPD but fails to reset
> > > > the corresponding VRR Capable Connector property.
> > > > Hence the userspace still sees this as VRR Capable panel which is incorrect.
> > > > 
> > > > Fix this by explicitly resetting the connector property.
> > > > 
> > > > v2: Reset vrr capable if status == connector_disconnected
> > > > v3: Use i915 and use bool vrr_capable (Jani Nikula)
> > > > v4: Move vrr_capable to after update modes call (Jani N)
> > > > Remove the redundant comment (Jan N)
> > > > v5: Fixes the regression on older platforms by reseting the VRR
> > > > only if HAS_VRR
> > > > v6: Remove the checks from driver, add in drm core before
> > > > setting VRR prop (Ville)
> > > > 
> > > > Cc: Jani Nikula <jani.nikula@intel.com>
> > > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > > Fixes: 390a1f8beb87 ("Revert "drm/i915/display/vrr: Reset VRR capable property on a long hpd")
> > > > Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/display/intel_dp.c | 15 +++++++++++----
> > > >  1 file changed, 11 insertions(+), 4 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > > index 1046e7fe310a..f96123b56935 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > > @@ -4455,6 +4455,10 @@ intel_dp_detect(struct drm_connector *connector,
> > > >  		memset(&intel_dp->compliance, 0, sizeof(intel_dp->compliance));
> > > >  		memset(intel_dp->dsc_dpcd, 0, sizeof(intel_dp->dsc_dpcd));
> > > >  
> > > > +		/* Reset VRR Capable property on disconnect */
> > > > +		drm_connector_set_vrr_capable_property(connector,
> > > > +						       false);
> > > > +
> > > >  		if (intel_dp->is_mst) {
> > > >  			drm_dbg_kms(&dev_priv->drm,
> > > >  				    "MST device may have disappeared %d vs %d\n",
> > > > @@ -4569,15 +4573,18 @@ static int intel_dp_get_modes(struct drm_connector *connector)
> > > >  {
> > > >  	struct intel_connector *intel_connector = to_intel_connector(connector);
> > > >  	struct edid *edid;
> > > > +	struct drm_i915_private *i915 = to_i915(connector->dev);
> > > >  	int num_modes = 0;
> > > >  
> > > >  	edid = intel_connector->detect_edid;
> > > >  	if (edid) {
> > > > -		num_modes = intel_connector_update_modes(connector, edid);
> > > > +		bool vrr_capable;
> > > >  
> > > > -		if (intel_vrr_is_capable(connector))
> > > > -			drm_connector_set_vrr_capable_property(connector,
> > > > -							       true);
> > > > +		num_modes = intel_connector_update_modes(connector, edid);
> > > > +		vrr_capable = intel_vrr_is_capable(connector);
> > > > +		drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] VRR capable: %s\n",
> > > > +			    connector->base.id, connector->name, yesno(vrr_capable));
> > > > +		drm_connector_set_vrr_capable_property(connector, vrr_capable);
> > > 
> > > As mentioned on irc I think intel_dp_(un)set_edid() would be a better
> > > place for these.
> > 
> > Yes I guess I can add the above to check for vrr_capable and set it to true/false in intel_dp_set_edid()
> > 
> > But the resetting part needs to happen outside of intel_dp_unset_edid so that we dont always set it to false
> > before set_edid. It can just stay in intel_dp_detect where we clear other othing on connect status == disconnected.
> > Is that fine?
> > 
> > Manasi
> > 
> > > 
> > > >  	}
> > > >  
> > > >  	/* Also add fixed mode, which may or may not be present in EDID */
> > > > -- 
> > > > 2.19.1
> > > 
> > > -- 
> > > Ville Syrjälä
> > > Intel

-- 
Ville Syrjälä
Intel