[PATCH v5 3/3] drm/i915/dp: Expose connector VRR info via debugfs

[Manasi Navare]

On Wed, May 13, 2020 at 04:08:38AM -0700, Modem, Bhanuprakash wrote:
> -----Original Message-----
> From: Navare, Manasi D <manasi.d.navare at intel.com>
> Sent: Wednesday, May 13, 2020 11:05 AM
> To: intel-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org
> Cc: Modem, Bhanuprakash <bhanuprakash.modem at intel.com>; Navare, Manasi D <manasi.d.navare at intel.com>; Jani Nikula <jani.nikula at linux.intel.com>; Ville Syrjälä <ville.syrjala at linux.intel.com>
> Subject: [PATCH v5 3/3] drm/i915/dp: Expose connector VRR info via debugfs
> 
> 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, "i915_vrr_info".
> 
> Example usage: cat /sys/kernel/debug/dri/0/DP-1/i915_vrr_info
> 
> [Bhanu]: Can you please fix the commit message? 's/i915_vrr_info/vrr_range/'
> 
> 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)
> 
> 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 70525623bcdf..a0d680c13e0d 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)));
> [Bhanu]: As we can read "vrr_capable" property from DRM_IOCTL_MODE_OBJ_GETPROPERTIES ioctl, I think we don't need to expose "vrr_capable" through debugfs.

Yes we can get it with the Get prop IOCTL, but having it in debugfs will still be a good debug info without
needing to call the ioctl

Manasi

> +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 @@ -2219,10 +2234,15 @@ int intel_connector_debugfs_add(struct drm_connector *connector)
> 
>  if (INTEL_GEN(dev_priv) >= 10 &&
>      (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
> -     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);
> +}
> +
>  /* Legacy panels doesn't lpsp on any platform */
>  if ((INTEL_GEN(dev_priv) >= 9 || IS_HASWELL(dev_priv) ||
>       IS_BROADWELL(dev_priv)) &&
> --
> 2.19.1
>