Re: [PATCH v4 2/5] drm/i915/3dlut: disable 3D LUT for pre-GLK

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] drm/i915: 3D LUT remains disabled for GLK/ICL due to unmodified version check
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commit 31c6b1070ace7be34ebe695316e80a7d65a5d1a7
Author: Michał Grzelak <michal.grzelak@linux.intel.com>
Subject: drm/i915/3dlut: disable 3D LUT for pre-GLK

This commit adds a has_3dlut field to the display runtime info to indicate
whether 3D LUT is enabled. It initializes the field to 1 for GLK and newer
platforms, and adds a HAS_3DLUT macro to check for support.

> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
> index f1df0f9ba7624..95de75e1de984 100644
> --- a/drivers/gpu/drm/i915/display/intel_color.c
> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> @@ -4304,6 +4304,9 @@ intel_color_load_plane_luts(struct intel_dsb *dsb,
>  bool
>  intel_color_crtc_has_3dlut(struct intel_display *display, enum pipe pipe)
>  {
> +	if (!HAS_3DLUT(display))
> +		return false;
> +
>  	if (DISPLAY_VER(display) >= 12)
>  		return pipe == PIPE_A || pipe == PIPE_B;
>  	else
>  		return false;
>  }

[Severity: Medium]
Will this still return false for GLK and ICL platforms even though they have
the HAS_3DLUT flag set?

The commit message indicates 3D LUT is supported on GLK+ hardware, and the
patch sets has_3dlut = 1 for GLK (DISPLAY_VER = 10) and ICL (DISPLAY_VER = 11).
However, in intel_color_crtc_has_3dlut(), after the new HAS_3DLUT() check
passes for these platforms, the function still evaluates:

    if (DISPLAY_VER(display) >= 12)
        ...
    else
        return false;

Doesn't this existing version check unconditionally return false for GLK and
ICL, defeating the newly added flag and keeping 3D LUT disabled for these
platforms?

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Sashiko AI review · https://sashiko.dev/#/patchset/20261013204705.1574475-1-michal.grzelak@linux.intel.com?part=2