[Intel-gfx] [PATCH v7 3/3] drm/i915/dp: Expose connector VRR monitor range via debugfs

[Emil Velikov]

Hi Manasi,

On Sat, 13 Jun 2020 at 00:55, Manasi Navare <manasi.d.navare at intel.com> wrote:
>
> From: Bhanuprakash Modem <bhanuprakash.modem at intel.com>
>
> [Why]
> It's useful to know the min and max vrr range for IGT testing.
>
> [How]
> Expose the min and max vfreq for the connector via a debugfs file
> on the connector, "vrr_range".
>
> Example usage: cat /sys/kernel/debug/dri/0/DP-1/vrr_range
>
> v7:
> * Fix cmpilation due to rebase
> v6:
> * Rebase (manasi)
> v5:
> * Rename to vrr_range to match AMD debugfs
> v4:
> * Rebase
> v3:
> * Remove the unnecessary debug print (Manasi)
> v2:
> * Fix the typo in max_vfreq (Manasi)
> * Change the name of node to i915_vrr_info so we can add
> other vrr info for more debug info (Manasi)
> * Change the VRR capable to display Yes or No (Manasi)
> * Fix indentation checkpatch errors (Manasi)
>
Nit: generally revision log is listed in v2 -> v6 order.

> Signed-off-by: Bhanuprakash Modem <bhanuprakash.modem at intel.com>
> Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Tested-by: Manasi Navare <manasi.d.navare at intel.com>
> ---
>  .../drm/i915/display/intel_display_debugfs.c  | 22 ++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> index 28dd717e943a..2921f7d2a26e 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> @@ -2185,6 +2185,21 @@ static const struct file_operations i915_dsc_fec_support_fops = {
>         .write = i915_dsc_fec_support_write
>  };
>
> +static int vrr_range_show(struct seq_file *m, void *data)
> +{
> +       struct drm_connector *connector = m->private;
> +
> +       if (connector->status != connector_status_connected)
> +               return -ENODEV;
> +
> +       seq_printf(m, "Vrr_capable: %s\n", yesno(intel_dp_is_vrr_capable(connector)));
> +       seq_printf(m, "Min: %u\n", (u8)connector->display_info.monitor_range.min_vfreq);
> +       seq_printf(m, "Max: %u\n", (u8)connector->display_info.monitor_range.max_vfreq);
> +
> +       return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(vrr_range);
> +
>  /**
>   * intel_connector_debugfs_add - add i915 specific connector debugfs files
>   * @connector: pointer to a registered drm_connector
> @@ -2220,10 +2235,15 @@ int intel_connector_debugfs_add(struct drm_connector *connector)
>         if (INTEL_GEN(dev_priv) >= 10 &&
>             ((connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort &&
>               !to_intel_connector(connector)->mst_port) ||
> -            connector->connector_type == DRM_MODE_CONNECTOR_eDP))
> +            connector->connector_type == DRM_MODE_CONNECTOR_eDP)) {
>                 debugfs_create_file("i915_dsc_fec_support", S_IRUGO, root,
>                                     connector, &i915_dsc_fec_support_fops);
>
> +               if (INTEL_GEN(dev_priv) >= 12)
> +                       debugfs_create_file("vrr_range", S_IRUGO,
> +                                           root, connector, &vrr_range_fops);
> +       }
> +

I think this should be added by core drm. Ideally drm will add it
automatically for each connector that the driver has called
drm_connector_attach_vrr_capable_property() upon.

-Emil