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

[Golani, Mitulkumar Ajitkumar]

> -----Original Message-----
> From: Intel-gfx <intel-gfx-boun...@lists.freedesktop.org> On Behalf Of Ankit
> Nautiyal
> Sent: 18 August 2025 13:01
> To: intel-gfx@lists.freedesktop.org; intel...@lists.freedesktop.org
> Cc: ville.syrj...@linux.intel.com; Nautiyal, Ankit K
> <ankit.k.nauti...@intel.com>
> Subject: [PATCH 11/12] drm/i915/panel: Refactor helper to get highest fixed
> mode
> 
> Refactor intel_panel_highest_mode() to return the fixed mode with the
> highest pixel clock, removing the fallback to the adjusted mode. This makes 
> the
> function semantics clearer and better suited for future use cases where
> fallback is not desirable.
> 
> Update the caller in intel_dp_mode_clock() to handle the NULL case explicitly
> by falling back to the adjusted mode's crtc_clock. This also addresses the
> existing FIXME comment about ambiguity between clock and crtc_clock, by
> using mode->clock for fixed modes and mode->crtc_clock for adjusted modes.
> 
> v2: Avoid introducing a new function and refactor existing one instead.
> (Jani).
> 
> Signed-off-by: Ankit Nautiyal <ankit.k.nauti...@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c    | 14 +++++++++-----
>  drivers/gpu/drm/i915/display/intel_panel.c | 11 +++++------
> drivers/gpu/drm/i915/display/intel_panel.h |  3 +--
>  3 files changed, 15 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 0c2bec1fbe42..2fa80b2750f8 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -1759,11 +1759,15 @@ static int intel_dp_mode_clock(const struct
> intel_crtc_state *crtc_state,
>       struct intel_connector *connector = to_intel_connector(conn_state-
> >connector);
>       const struct drm_display_mode *adjusted_mode = &crtc_state-
> >hw.adjusted_mode;
> 
> -     /* FIXME a bit of a mess wrt clock vs. crtc_clock */
> -     if (has_seamless_m_n(connector))
> -             return intel_panel_highest_mode(connector,
> adjusted_mode)->clock;
> -     else
> -             return adjusted_mode->crtc_clock;
> +     if (has_seamless_m_n(connector)) {
> +             const struct drm_display_mode *highest_mode;
> +
> +             highest_mode = intel_panel_highest_mode(connector);
> +             if (highest_mode)
> +                     return highest_mode->clock;
> +     }
> +
> +     return adjusted_mode->crtc_clock;
>  }
> 
>  /* Optimize link config in order: max bpp, min clock, min lanes */ diff --git
> a/drivers/gpu/drm/i915/display/intel_panel.c
> b/drivers/gpu/drm/i915/display/intel_panel.c
> index 2a20aaaaac39..ac0f04073ecb 100644
> --- a/drivers/gpu/drm/i915/display/intel_panel.c
> +++ b/drivers/gpu/drm/i915/display/intel_panel.c
> @@ -144,18 +144,17 @@ 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)
> +intel_panel_highest_mode(struct intel_connector *connector)
>  {
> -     const struct drm_display_mode *fixed_mode, *best_mode =
> adjusted_mode;
> +     const struct drm_display_mode *fixed_mode, *highest_mode = NULL;
> 
>       /* pick the fixed_mode that has the highest clock */
>       list_for_each_entry(fixed_mode, &connector->panel.fixed_modes,
> head) {
> -             if (fixed_mode->clock > best_mode->clock)
> -                     best_mode = fixed_mode;
> +             if (!highest_mode || fixed_mode->clock > highest_mode-
> >clock)
> +                     highest_mode = fixed_mode;
>       }
> 
> -     return best_mode;
> +     return highest_mode;
>  }
> 
>  int intel_panel_get_modes(struct intel_connector *connector) diff --git
> a/drivers/gpu/drm/i915/display/intel_panel.h
> b/drivers/gpu/drm/i915/display/intel_panel.h
> index 56a6412cf0fb..8a17600e46a3 100644
> --- a/drivers/gpu/drm/i915/display/intel_panel.h
> +++ b/drivers/gpu/drm/i915/display/intel_panel.h
> @@ -37,8 +37,7 @@ const struct drm_display_mode *
> intel_panel_downclock_mode(struct intel_connector *connector,
>                          const struct drm_display_mode *adjusted_mode);
> const struct drm_display_mode * -intel_panel_highest_mode(struct
> intel_connector *connector,
> -                      const struct drm_display_mode *adjusted_mode);
> +intel_panel_highest_mode(struct intel_connector *connector);

Reviewed-by: Mitul Golani <mitulkumar.ajitkumar.gol...@intel.com>

>  int intel_panel_get_modes(struct intel_connector *connector);  enum
> drrs_type intel_panel_drrs_type(struct intel_connector *connector);  enum
> drm_mode_status
> --
> 2.45.2