Re: [Intel-gfx] [PATCH v7] drm/i915/display/vrr: Reset VRR capable property on a long hpd

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

On Thu, Mar 03, 2022 at 03:32:22PM -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)
> v7: Move VRR set/reset to set/unset_edid (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>

Looks reasoanble enough to me.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

But be careful when pushing this since I don't think
the drm_connector_set_vrr_capable_property() change has
percolated into drm-intel-next yet.

> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index d6ef33096bb6..1d0f8fc39005 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4385,13 +4385,20 @@ intel_dp_update_420(struct intel_dp *intel_dp)
>  static void
>  intel_dp_set_edid(struct intel_dp *intel_dp)
>  {
> +	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
>  	struct intel_connector *connector = intel_dp->attached_connector;
>  	struct edid *edid;
> +	bool vrr_capable;
>  
>  	intel_dp_unset_edid(intel_dp);
>  	edid = intel_dp_get_edid(intel_dp);
>  	connector->detect_edid = edid;
>  
> +	vrr_capable = intel_vrr_is_capable(&connector->base);
> +	drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] VRR capable: %s\n",
> +		    connector->base.base.id, connector->base.name, str_yes_no(vrr_capable));
> +	drm_connector_set_vrr_capable_property(&connector->base, vrr_capable);
> +
>  	intel_dp_update_dfp(intel_dp, edid);
>  	intel_dp_update_420(intel_dp);
>  
> @@ -4424,6 +4431,9 @@ intel_dp_unset_edid(struct intel_dp *intel_dp)
>  
>  	intel_dp->dfp.ycbcr_444_to_420 = false;
>  	connector->base.ycbcr_420_allowed = false;
> +
> +	drm_connector_set_vrr_capable_property(&connector->base,
> +					       false);
>  }
>  
>  static int
> @@ -4574,14 +4584,9 @@ static int intel_dp_get_modes(struct drm_connector *connector)
>  	int num_modes = 0;
>  
>  	edid = intel_connector->detect_edid;
> -	if (edid) {
> +	if (edid)
>  		num_modes = intel_connector_update_modes(connector, edid);
>  
> -		if (intel_vrr_is_capable(connector))
> -			drm_connector_set_vrr_capable_property(connector,
> -							       true);
> -	}
> -
>  	/* Also add fixed mode, which may or may not be present in EDID */
>  	if (intel_dp_is_edp(intel_attached_dp(intel_connector)) &&
>  	    intel_connector->panel.fixed_mode) {
> -- 
> 2.19.1

-- 
Ville Syrjälä
Intel