[PATCH V11 35/47] drm/colorop: Add 1D Curve Custom LUT type

[Alex Hung]

On 8/19/25 09:31, Sebastian Wick wrote:
>> +/**
>> + * drm_plane_colorop_curve_1d_lut_init - Initialize a DRM_COLOROP_1D_LUT
>> + *
>> + * @dev: DRM device
>> + * @colorop: The drm_colorop object to initialize
>> + * @plane: The associated drm_plane
>> + * @lut_size: LUT size supported by driver
>> + * @return zero on success, -E value on failure
>> + */
>> +int drm_plane_colorop_curve_1d_lut_init(struct drm_device *dev, struct drm_colorop *colorop,
>> +					struct drm_plane *plane, uint32_t lut_size)
>> +{
>> +	struct drm_property *prop;
>> +	int ret;
>> +
>> +	ret = drm_plane_colorop_init(dev, colorop, plane, DRM_COLOROP_1D_LUT);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* initialize 1D LUT only attribute */
>> +	/* LUT size */
>> +	prop = drm_property_create_range(dev, DRM_MODE_PROP_IMMUTABLE | DRM_MODE_PROP_ATOMIC,
>> +					 "SIZE", 0, UINT_MAX);
>> +	if (!prop)
>> +		return -ENOMEM;
>> +
>> +	colorop->lut_size_property = prop;
> I'm a bit confused here. The property itself is just called "SIZE" which
> looks very similar to the generic "DATA" property. However, it is
> assigned to `lut_size_property`.
> 
> Is this meant to be to be a generic property where the exact usage
> depends on the type of the color op (like "DATA"), or is this meant to
> be specific to LUTs (in which case the generic name is misleading)?
> 
> I also tried to find the user space documentation for all the properties
> but could not find them. The only thing I could find was the kernel
> documentation of
> 
>      struct drm_property *lut_size_property;
> 
> Which says "Size property for custom LUT from userspace."

In earlier version, this lut_size was specific to 1D LUT and 3D LUT has 
a dedicate lut size field in another struct, and lut_size_property is 
now used for both 1D and 3D LUTs.

Do you mean we clarify by making either changes?
1) "SIZE" to "LUT_SIZE"
     -> specific to LUTs
2) "lut_size" and "lut_size_property" "size" and "size_property", 
respectively
    -> Can be reused in the future, if any.