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

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 12 Jan 2022, Manasi Navare <manasi.d.navare@intel.com> 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.
>
> Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index df2a7d86aef0..4f1418f02b76 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -4539,15 +4539,24 @@ 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 *dev_priv = to_i915(connector->dev);

Please call it "i915" for new stuff.

>  	int num_modes = 0;
>  
>  	edid = intel_connector->detect_edid;
>  	if (edid) {
>  		num_modes = intel_connector_update_modes(connector, edid);
>  
> -		if (intel_vrr_is_capable(connector))
> +		if (intel_vrr_is_capable(connector)) {
> +			drm_dbg_kms(&dev_priv->drm, "VRR capable  = TRUE for [CONNECTOR:%d:%s]\n",
> +				    connector->base.id, connector->name);
>  			drm_connector_set_vrr_capable_property(connector,
>  							       true);
> +		} else {
> +			drm_dbg_kms(&dev_priv->drm, "VRR capable = false for [CONNECTOR:%d:%s]\n",
> +				    connector->base.id, connector->name);
> +			drm_connector_set_vrr_capable_property(connector,
> +							       false);
> +		}

Please don't repeat yourself! Also, prefer having [CONNECTOR:%d:%s] at
the beginning.

		bool capable = intel_vrr_is_capable(connector);

		drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] VRR capable: %s\n",
			    connector->base.id, connector->name, yesno(capable));
                drm_connector_set_vrr_capable_property(connector, capable);

BR,
Jani.


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

-- 
Jani Nikula, Intel Open Source Graphics Center