Re: [PATCH 11/12] drm/i915/panel: Add helper to get highest fixed mode

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

On Thu, 07 Aug 2025, Ankit Nautiyal <ankit.k.nautiyal@intel.com> wrote:
> Add intel_panel_highest_fixed_mode() to return the fixed mode with the
> highest pixel clock. Unlike intel_panel_highest_mode(), this function
> does not fall back to the adjusted mode and returns NULL if no fixed
> modes are available.
>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_panel.c | 13 +++++++++++++
>  drivers/gpu/drm/i915/display/intel_panel.h |  2 ++
>  2 files changed, 15 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c
> index 2a20aaaaac39..ea4351d11e63 100644
> --- a/drivers/gpu/drm/i915/display/intel_panel.c
> +++ b/drivers/gpu/drm/i915/display/intel_panel.c
> @@ -158,6 +158,19 @@ intel_panel_highest_mode(struct intel_connector *connector,
>  	return best_mode;
>  }
>  
> +const struct drm_display_mode *
> +intel_panel_highest_fixed_mode(struct intel_connector *connector)
> +{
> +	const struct drm_display_mode *fixed_mode, *highest_mode = NULL;
> +
> +	list_for_each_entry(fixed_mode, &connector->panel.fixed_modes, head) {
> +		if (!highest_mode || fixed_mode->clock > highest_mode->clock)
> +			highest_mode = fixed_mode;
> +	}
> +
> +	return highest_mode;
> +}

The difference in naming here does not adequately describe the
difference in the functions.

Or you could just make the single user of intel_panel_highest_mode()
fall back to adjusted mode when the return value is NULL, and avoid that
problem altogether.

BR,
Jani.

> +
>  int intel_panel_get_modes(struct intel_connector *connector)
>  {
>  	const struct drm_display_mode *fixed_mode;
> diff --git a/drivers/gpu/drm/i915/display/intel_panel.h b/drivers/gpu/drm/i915/display/intel_panel.h
> index 56a6412cf0fb..60f6873cdbaa 100644
> --- a/drivers/gpu/drm/i915/display/intel_panel.h
> +++ b/drivers/gpu/drm/i915/display/intel_panel.h
> @@ -39,6 +39,8 @@ intel_panel_downclock_mode(struct intel_connector *connector,
>  const struct drm_display_mode *
>  intel_panel_highest_mode(struct intel_connector *connector,
>  			 const struct drm_display_mode *adjusted_mode);
> +const struct drm_display_mode *
> +intel_panel_highest_fixed_mode(struct intel_connector *connector);
>  int intel_panel_get_modes(struct intel_connector *connector);
>  enum drrs_type intel_panel_drrs_type(struct intel_connector *connector);
>  enum drm_mode_status

-- 
Jani Nikula, Intel