Re: [PATCH i-g-t 4/6] tests/kms_color_pipeline: Add FIXED_MATRIX colorop tests

On 8/6/2026 5:33 PM, Swati Sharma wrote:
> Add plane color pipeline tests for the DRM_COLOROP_FIXED_MATRIX colorop,
> validating color space conversion through the color pipeline framework.
> 
> With this, the SDR plane color pipeline looks like:
> 
> [YUV Full/Limited -> RGB] -> [1D LUT]
> 
> A single FIXED_MATRIX colorop now handles both full and limited range
> YCbCr to RGB conversion.
> 

I would remove the 'now' from here.

> New subtests:
>   - plane-fixed-matrix-yuv-rgb-bt601
>   - plane-fixed-matrix-yuv-rgb-bt709
>   - plane-fixed-matrix-yuv-rgb-bt2020
>   - plane-fixed-matrix-yuv-rgb-bt601-lim
>   - plane-fixed-matrix-yuv-rgb-bt709-lim
>   - plane-fixed-matrix-yuv-rgb-bt2020-lim
>   - plane-fixed-matrix-yuv-rgb-bt601-lut1d
>   - plane-fixed-matrix-yuv-rgb-bt709-lut1d
>   - plane-fixed-matrix-yuv-rgb-bt2020-lut1d
>   - plane-fixed-matrix-yuv-rgb-bt601-lim-lut1d
>   - plane-fixed-matrix-yuv-rgb-bt709-lim-lut1d
>   - plane-fixed-matrix-yuv-rgb-bt2020-lim-lut1d
> 
> The test works as follows:
> 1. Creates a YUYV framebuffer with the appropriate color encoding
> 2. Converts it to XRGB8888 in software using igt_fb_convert() which
>     internally uses igt_ycbcr_to_rgb_matrix() with the matching
>     coefficients
> 3. Displays the SW-converted RGB fb and captures its CRC as reference
> 4. Programs the HW color pipeline with the FIXED_MATRIX colorop set to
>     the corresponding matrix type
> 5. Displays the original YUYV fb through the HW pipeline and compares
>     the resulting CRC against the SW reference
> 
> This ensures the HW fixed matrix implementation matches the expected
> YCbCr-to-RGB conversion behavior.
> 
> Also refactors ctm_colorop_only() into a generic colorop_type_only()
> helper that accepts the colorop type as a parameter.
> 

Is this change needed anymore?

> v2: -Naming changes (CSC_FF -> FIXED_MATRIX)
>      -Use SW-generated reference CRC (igt_fb_convert) for YUV tests
>      -Remove redundant tests
> v3: -Drop YCbCr limited to full and RGB709 to RGB2020 matrices
>       until we have non-IGT userspace that shows their use
>      -Add limited range YCbCr to RGB tests
>      -Consolidate all tests under single plane-fixed-matrix prefix
> 
> Assisted-by: Claude Opus 4.6
> Signed-off-by: Swati Sharma <[email protected]>
> ---
>   tests/kms_color_pipeline.c | 342 ++++++++++++++++++++++++++++++++++++-
>   1 file changed, 339 insertions(+), 3 deletions(-)
> 
> diff --git a/tests/kms_color_pipeline.c b/tests/kms_color_pipeline.c
> index 78860a845..3e821f8de 100644
> --- a/tests/kms_color_pipeline.c
> +++ b/tests/kms_color_pipeline.c
> @@ -13,6 +13,7 @@
>   
>   #include "kms_color_helper.h"
>   #include "kms_colorop_helper.h"
> +#include "igt_color_encoding.h"
>   
>   #define MAX_COLOROPS	5
>   
> @@ -69,7 +70,8 @@ static void test_setup(data_t *data, igt_crtc_t *crtc)
>   	igt_display_commit_atomic(&data->display, DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
>   }
>   
> -static bool ctm_colorop_only(kms_colorop_t *colorops[])
> +static bool colorop_type_only(kms_colorop_t *colorops[],
> +			      kms_colorop_type_t type)
>   {
>   	int i;
>   
> @@ -77,7 +79,7 @@ static bool ctm_colorop_only(kms_colorop_t *colorops[])
>   		return false;
>   
>   	for (i = 0; colorops[i]; i++) {
> -		if (colorops[i]->type != KMS_COLOROP_CTM_3X4)
> +		if (colorops[i]->type != type)
>   			return false;
>   	}
>   
> @@ -155,7 +157,7 @@ static void _test_plane_colorops(data_t *data,
>   	 * Use flat colors only when the pipeline
>   	 * contains CTM colorops exclusively.
>   	 */
> -	if (ctm_colorop_only(colorops))
> +	if (colorop_type_only(colorops, KMS_COLOROP_CTM_3X4))
>   		paint_rectangles(data, mode, fb_colors, &fb);
>   	else
>   		paint_gradient_rectangles(data, mode, fb_colors, &fb);
> @@ -347,6 +349,337 @@ run_tests_for_plane(data_t *data)
>   	}
>   }
>   
> +
> +/**
> + * Capture reference CRC by converting a YUV framebuffer to RGB in software
> + * using igt_fb_convert(), then displaying the resulting XRGB8888 framebuffer.
> + */
> +static void
> +capture_sw_converted_ref_crc(data_t *data, igt_output_t *output,
> +			     struct igt_fb *yuv_fb, igt_crc_t *crc /* out */)
> +{
> +	struct igt_fb rgb_ref_fb;
> +	igt_plane_t *primary;
> +	char *crc_str;
> +	int ret;
> +
> +	primary = igt_output_get_plane(output, DRM_PLANE_TYPE_PRIMARY);
> +
> +	/* Convert YUV fb to XRGB8888 in software (uses igt_ycbcr_to_rgb_matrix) */
> +	igt_fb_convert(&rgb_ref_fb, yuv_fb, DRM_FORMAT_XRGB8888,
> +		       DRM_FORMAT_MOD_LINEAR);
> +
> +	igt_plane_set_fb(primary, &rgb_ref_fb);
> +	ret = igt_display_try_commit_atomic(&data->display, 0, NULL);
> +	igt_assert(!ret);
> +
> +	igt_wait_for_vblank(primary->crtc);
> +	igt_pipe_crc_collect_crc(data->pipe_crc, crc);
> +
> +	igt_plane_set_fb(primary, NULL);
> +	igt_display_commit_atomic(&data->display, 0, NULL);
> +
> +	igt_remove_fb(data->drm_fd, &rgb_ref_fb);
> +
> +	crc_str = igt_crc_to_string(crc);
> +	igt_debug("CRC for SW-converted reference fb: %s\n", crc_str);
> +	free(crc_str);
> +}
> +
> +static void
> +_test_plane_fixed_matrix_colorops(data_t *data,
> +				  igt_plane_t *plane,
> +				  const color_t *fb_colors,
> +				  igt_crc_t *crc_ref,
> +				  kms_colorop_t *colorops[],
> +				  uint32_t input_format,
> +				  enum igt_color_encoding encoding,
> +				  enum igt_color_range range)

Can we re-use _test_plane_colorops() if go with 
kms_colorop_fixed_matrix_info used in

https://lore.kernel.org/igt-dev/[email protected]/

> +{
> +	igt_display_t *display = &data->display;
> +	drmModeModeInfo *mode = data->mode;
> +	igt_colorop_t *color_pipeline;
> +	igt_crc_t crc_pipe;
> +	struct igt_fb fb;
> +
> +	color_pipeline = get_color_pipeline(display, plane, colorops);
> +	igt_skip_on(!color_pipeline);
> +
> +	igt_assert(igt_create_fb_with_bo_size(data->drm_fd,
> +					      mode->hdisplay,
> +					      mode->vdisplay,
> +					      input_format,
> +					      DRM_FORMAT_MOD_LINEAR,
> +					      encoding, range,
> +					      &fb, 0, 0));
> +
> +	/* Hardware pipeline CRC */
> +	set_color_pipeline(display, plane, colorops, color_pipeline);
> +	paint_rectangles(data, mode, fb_colors, &fb);
> +
> +	igt_plane_set_fb(plane, &fb);
> +	igt_display_commit_atomic(&data->display, 0, NULL);
> +	igt_wait_for_vblank(plane->crtc);
> +	igt_pipe_crc_collect_crc(data->pipe_crc, &crc_pipe);
> +
> +	igt_assert_crc_equal(crc_ref, &crc_pipe);
> +

We have to be careful with the assert here. When lets say plane 0 fails 
and the test moves on to plane 1, the plane 0 remains active when assert 
fails here. Therefore, plane 0 continues to blend with plane 1 while we 
should be only testing plane 1. This is a problem with 
_test_plane_colorops() too. Simple solution could be to move the clean 
up code before the assert.

> +	/* Cleanup per-test state */
> +	set_color_pipeline_bypass(plane);
> +	reset_colorops(colorops);
> +	igt_plane_set_fb(plane, NULL);
> +	igt_display_commit_atomic(&data->display, 0, NULL);
> +
> +	igt_remove_fb(data->drm_fd, &fb);
> +}
> +
> +static void test_plane_fixed_matrix_colorops(data_t *data, igt_crtc_t *crtc,
> +					     const color_t *fb_colors,
> +					     kms_colorop_t *colorops[],
> +					     uint32_t input_format,
> +					     enum igt_color_encoding encoding,
> +					     enum igt_color_range range)
> +{
> +	int n_planes = crtc->n_planes;
> +	igt_output_t *output = data->output;
> +	drmModeModeInfo *mode = data->mode;
> +	igt_plane_t *plane;
> +	igt_crc_t ref_crc;
> +	struct igt_fb yuv_fb;
> +
> +	igt_require(mode);
> +
> +	igt_assert(igt_create_fb_with_bo_size(data->drm_fd,
> +					      mode->hdisplay,
> +					      mode->vdisplay,
> +					      input_format,
> +					      DRM_FORMAT_MOD_LINEAR,
> +					      encoding, range,
> +					      &yuv_fb, 0, 0));
> +	paint_rectangles(data, mode, fb_colors, &yuv_fb);
> +
> +	capture_sw_converted_ref_crc(data, output, &yuv_fb, &ref_crc);
> +	igt_remove_fb(data->drm_fd, &yuv_fb);
> +
> +	for (int plane_id = 0; plane_id < n_planes; plane_id++) {
> +		plane = igt_output_get_plane(output, plane_id);
> +
> +		if (!igt_plane_has_prop(plane, IGT_PLANE_COLOR_PIPELINE))
> +			continue;
> +
> +		igt_dynamic_f("pipe-%s-plane-%u", igt_crtc_name(crtc), plane_id)
> +			_test_plane_fixed_matrix_colorops(data, plane, fb_colors,
> +							  &ref_crc, colorops,
> +							  input_format,
> +							  encoding, range);
> +	}
> +}
> +
> +/**
> + * SUBTEST: plane-fixed-matrix-%s
> + * Description: Test FIXED_MATRIX colorop for color space conversion: %arg[1].
> + *
> + * arg[1]:
> + *
> + * @yuv-rgb-bt601:		YUV BT.601 full range to RGB BT.601
> + * @yuv-rgb-bt709:		YUV BT.709 full range to RGB BT.709
> + * @yuv-rgb-bt2020:		YUV BT.2020 full range to RGB BT.2020
> + * @yuv-rgb-bt601-lim:		YUV BT.601 limited range to RGB BT.601
> + * @yuv-rgb-bt709-lim:		YUV BT.709 limited range to RGB BT.709
> + * @yuv-rgb-bt2020-lim:	YUV BT.2020 limited range to RGB BT.2020
> + * @yuv-rgb-bt601-lut1d:	YUV BT.601 full range to RGB BT.601, then 1D LUT
> + * @yuv-rgb-bt709-lut1d:	YUV BT.709 full range to RGB BT.709, then 1D LUT
> + * @yuv-rgb-bt2020-lut1d:	YUV BT.2020 full range to RGB BT.2020, then 1D LUT
> + * @yuv-rgb-bt601-lim-lut1d:	YUV BT.601 limited range to RGB BT.601, then 1D LUT
> + * @yuv-rgb-bt709-lim-lut1d:	YUV BT.709 limited range to RGB BT.709, then 1D LUT
> + * @yuv-rgb-bt2020-lim-lut1d:	YUV BT.2020 limited range to RGB BT.2020, then 1D LUT
> + */
> +
> +static void
> +run_tests_for_fixed_matrix(data_t *data)
> +{
> +	igt_crtc_t *crtc;
> +	igt_output_t *output = NULL;
> +
> +	static const color_t colors_rgb[] = {
> +		{ 1.0, 0.0, 0.0 },
> +		{ 0.0, 1.0, 0.0 },
> +		{ 0.0, 0.0, 1.0 },
> +	};
> +
> +	kms_colorop_t lut1d_linear = {
> +		.type = KMS_COLOROP_CUSTOM_LUT1D,
> +		.name = "1D LUT (linear)",
> +		.lut1d = &igt_1dlut_linear,
> +		.transform = &igt_color_linear,
> +	};
> +
> +	kms_colorop_t fixed_matrix_yuv601_rgb601 = {
> +		.type = KMS_COLOROP_FIXED_MATRIX,
> +		.name = "FIXED_MATRIX YUV601 to RGB601",
> +		.fixed_matrix_info = { .fixed_matrix = KMS_COLOROP_FIXED_MATRIX_YCBCR601_FULL_RGB },
> +	};
> +	kms_colorop_t fixed_matrix_yuv709_rgb709 = {
> +		.type = KMS_COLOROP_FIXED_MATRIX,
> +		.name = "FIXED_MATRIX YUV709 to RGB709",
> +		.fixed_matrix_info = { .fixed_matrix = KMS_COLOROP_FIXED_MATRIX_YCBCR709_FULL_RGB },
> +	};
> +	kms_colorop_t fixed_matrix_yuv2020_rgb2020 = {
> +		.type = KMS_COLOROP_FIXED_MATRIX,
> +		.name = "FIXED_MATRIX YUV2020 to RGB2020",
> +		.fixed_matrix_info = { .fixed_matrix = KMS_COLOROP_FIXED_MATRIX_YCBCR2020_NC_FULL_RGB },
> +	};
> +	kms_colorop_t fixed_matrix_yuv601_rgb601_lim = {
> +		.type = KMS_COLOROP_FIXED_MATRIX,
> +		.name = "FIXED_MATRIX YUV601 limited to RGB601",
> +		.fixed_matrix_info = { .fixed_matrix = KMS_COLOROP_FIXED_MATRIX_YCBCR601_LIMITED_RGB },
> +	};
> +	kms_colorop_t fixed_matrix_yuv709_rgb709_lim = {
> +		.type = KMS_COLOROP_FIXED_MATRIX,
> +		.name = "FIXED_MATRIX YUV709 limited to RGB709",
> +		.fixed_matrix_info = { .fixed_matrix = KMS_COLOROP_FIXED_MATRIX_YCBCR709_LIMITED_RGB },
> +	};
> +	kms_colorop_t fixed_matrix_yuv2020_rgb2020_lim = {
> +		.type = KMS_COLOROP_FIXED_MATRIX,
> +		.name = "FIXED_MATRIX YUV2020 limited to RGB2020",
> +		.fixed_matrix_info = { .fixed_matrix = KMS_COLOROP_FIXED_MATRIX_YCBCR2020_NC_LIMITED_RGB },
> +	};
> +
> +	struct {
> +		const char *name;
> +		const char *subtest_prefix;
> +		const color_t *fb_colors;
> +		kms_colorop_t *colorops[MAX_COLOROPS];
> +		uint32_t input_format;
> +		enum igt_color_encoding encoding;
> +		enum igt_color_range range;
> +	} fixed_matrix_tests[] = {
> +		{ .name = "yuv-rgb-bt601",
> +		  .subtest_prefix = "plane-fixed-matrix",

Do we really need these?

How about

igt_subtest_with_dynamic_f("plane-fixed-matrix-%s", ...)

?

> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv601_rgb601, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT601,
> +		  .range = IGT_COLOR_YCBCR_FULL_RANGE,
> +		},
> +		{ .name = "yuv-rgb-bt709",
> +		  .subtest_prefix = "plane-fixed-matrix",
> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv709_rgb709, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT709,
> +		  .range = IGT_COLOR_YCBCR_FULL_RANGE,
> +		},
> +		{ .name = "yuv-rgb-bt2020",
> +		  .subtest_prefix = "plane-fixed-matrix",
> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv2020_rgb2020, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT2020,
> +		  .range = IGT_COLOR_YCBCR_FULL_RANGE,
> +		},
> +		{ .name = "yuv-rgb-bt601-lim",
> +		  .subtest_prefix = "plane-fixed-matrix",
> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv601_rgb601_lim, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT601,
> +		  .range = IGT_COLOR_YCBCR_LIMITED_RANGE,
> +		},
> +		{ .name = "yuv-rgb-bt709-lim",
> +		  .subtest_prefix = "plane-fixed-matrix",
> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv709_rgb709_lim, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT709,
> +		  .range = IGT_COLOR_YCBCR_LIMITED_RANGE,
> +		},
> +		{ .name = "yuv-rgb-bt2020-lim",
> +		  .subtest_prefix = "plane-fixed-matrix",
> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv2020_rgb2020_lim, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT2020,
> +		  .range = IGT_COLOR_YCBCR_LIMITED_RANGE,
> +		},
> +		{ .name = "yuv-rgb-bt601-lut1d",
> +		  .subtest_prefix = "plane-fixed-matrix",
> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv601_rgb601, &lut1d_linear, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT601,
> +		  .range = IGT_COLOR_YCBCR_FULL_RANGE,
> +		},
> +		{ .name = "yuv-rgb-bt709-lut1d",
> +		  .subtest_prefix = "plane-fixed-matrix",
> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv709_rgb709, &lut1d_linear, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT709,
> +		  .range = IGT_COLOR_YCBCR_FULL_RANGE,
> +		},
> +		{ .name = "yuv-rgb-bt2020-lut1d",
> +		  .subtest_prefix = "plane-fixed-matrix",
> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv2020_rgb2020, &lut1d_linear, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT2020,
> +		  .range = IGT_COLOR_YCBCR_FULL_RANGE,
> +		},
> +		{ .name = "yuv-rgb-bt601-lim-lut1d",
> +		  .subtest_prefix = "plane-fixed-matrix",
> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv601_rgb601_lim, &lut1d_linear, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT601,
> +		  .range = IGT_COLOR_YCBCR_LIMITED_RANGE,
> +		},
> +		{ .name = "yuv-rgb-bt709-lim-lut1d",
> +		  .subtest_prefix = "plane-fixed-matrix",
> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv709_rgb709_lim, &lut1d_linear, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT709,
> +		  .range = IGT_COLOR_YCBCR_LIMITED_RANGE,
> +		},
> +		{ .name = "yuv-rgb-bt2020-lim-lut1d",
> +		  .subtest_prefix = "plane-fixed-matrix",
> +		  .fb_colors = colors_rgb,
> +		  .colorops = { &fixed_matrix_yuv2020_rgb2020_lim, &lut1d_linear, NULL },
> +		  .input_format = DRM_FORMAT_YUYV,
> +		  .encoding = IGT_COLOR_YCBCR_BT2020,
> +		  .range = IGT_COLOR_YCBCR_LIMITED_RANGE,
> +		},
> +	};
> +
> +	for (int i = 0; i < ARRAY_SIZE(fixed_matrix_tests); i++) {
> +		igt_describe_f("Test FIXED_MATRIX pipeline: %s-%s",
> +			       fixed_matrix_tests[i].subtest_prefix,
> +			       fixed_matrix_tests[i].name);
> +		igt_subtest_with_dynamic_f("%s-%s",
> +					   fixed_matrix_tests[i].subtest_prefix,
> +					   fixed_matrix_tests[i].name) {
> +			for_each_crtc_with_single_output(&data->display, crtc,
> +							 output) {
> +				data->output = output;
> +
> +				if (!crtc_output_combo_valid(data, crtc))
> +					continue;
> +
> +				test_setup(data, crtc);
> +
> +				test_plane_fixed_matrix_colorops(data, crtc,
> +								 fixed_matrix_tests[i].fb_colors,
> +								 fixed_matrix_tests[i].colorops,
> +								 fixed_matrix_tests[i].input_format,
> +								 fixed_matrix_tests[i].encoding,
> +								 fixed_matrix_tests[i].range);
> +				test_cleanup(data);
> +			}
> +		}
> +	}
> +}
> +
>   int igt_main()
>   {
>   	int has_plane_color_pipeline = 0;
> @@ -377,6 +710,9 @@ int igt_main()
>   	igt_subtest_group()
>   		run_tests_for_plane(&data);
>   
> +	igt_subtest_group()
> +		run_tests_for_fixed_matrix(&data);
> +
>   	igt_fixture() {
>   		igt_display_fini(&data.display);
>   		drm_close_driver(data.drm_fd);