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 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.

>  	}
>  
>  	/* Also add fixed mode, which may or may not be present in EDID */
> -- 
> 2.19.1

-- 
Ville Syrjälä
Intel