Re: [PATCH v4 6/8] drm/vkms: Change YUV helpers to support u16 inputs for conversion

["Maíra Canal" <mcanal@igalia.com>]

Hi Louis,

On 5/30/25 11:06, Louis Chauvet wrote:
> Some YUV format uses 16 bit values, so change the helper function for
> conversion to support those new formats.
> 
> Add support for the YUV format P010

Hum, I don't think this patch added support for P010.

> 
> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> ---
>   drivers/gpu/drm/vkms/tests/vkms_format_test.c | 103 +++++++++++++-------------
>   drivers/gpu/drm/vkms/vkms_formats.c           |  26 ++++---
>   drivers/gpu/drm/vkms/vkms_formats.h           |   4 +-
>   3 files changed, 68 insertions(+), 65 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vkms/tests/vkms_format_test.c b/drivers/gpu/drm/vkms/tests/vkms_format_test.c
> index 2e1daef94831..272e18a82f9c 100644
> --- a/drivers/gpu/drm/vkms/tests/vkms_format_test.c
> +++ b/drivers/gpu/drm/vkms/tests/vkms_format_test.c
> @@ -23,7 +23,7 @@ MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
>    *     machine endianness
>    */
>   struct pixel_yuv_u8 {
> -	u8 y, u, v;
> +	u16 y, u, v;
>   };
>   
>   /*
> @@ -64,7 +64,7 @@ static struct yuv_u8_to_argb_u16_case yuv_u8_to_argb_u16_cases[] = {
>   	 *                     in_bits = 16,
>   	 *                     in_legal = False,
>   	 *                     in_int = True,
> -	 *                     out_bits = 8,
> +	 *                     out_bits = 16,
>   	 *                     out_legal = False,
>   	 *                     out_int = True)
>   	 *
> @@ -76,13 +76,13 @@ static struct yuv_u8_to_argb_u16_case yuv_u8_to_argb_u16_cases[] = {
>   		.range = DRM_COLOR_YCBCR_FULL_RANGE,
>   		.n_colors = 6,
>   		.colors = {
> -			{ "white", { 0xff, 0x80, 0x80 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
> -			{ "gray",  { 0x80, 0x80, 0x80 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
> -			{ "black", { 0x00, 0x80, 0x80 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
> -			{ "red",   { 0x4c, 0x55, 0xff }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
> -			{ "green", { 0x96, 0x2c, 0x15 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
> -			{ "blue",  { 0x1d, 0xff, 0x6b }, { 0xffff, 0x0000, 0x0000, 0xffff }},
> -		},
> +			{ "white",	{ 0xffff, 0x8000, 0x8000 }, { 0xffff, 0xffff, 0xffff, 0xffff }},
> +			{ "gray",	{ 0x8080, 0x8000, 0x8000 }, { 0xffff, 0x8080, 0x8080, 0x8080 }},
> +			{ "black",	{ 0x0000, 0x8000, 0x8000 }, { 0xffff, 0x0000, 0x0000, 0x0000 }},
> +			{ "red",	{ 0x4c8b, 0x54ce, 0xffff }, { 0xffff, 0xffff, 0x0000, 0x0000 }},
> +			{ "green",	{ 0x9645, 0x2b33, 0x14d1 }, { 0xffff, 0x0000, 0xffff, 0x0000 }},
> +			{ "blue",	{ 0x1d2f, 0xffff, 0x6b2f }, { 0xffff, 0x0000, 0x0000, 0xffff }},

Is there an explicit need of those tabs? They make the line length
exceed 100 columns.

[...]

> diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
> index 5106441f916b..261e822e9618 100644
> --- a/drivers/gpu/drm/vkms/vkms_formats.c
> +++ b/drivers/gpu/drm/vkms/vkms_formats.c
> @@ -279,16 +279,17 @@ static struct pixel_argb_u16 argb_u16_from_BGR565(const __le16 *pixel)
>   	return out_pixel;
>   }
>   
> -VISIBLE_IF_KUNIT struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1, u8 channel_2,
> -							    const struct conversion_matrix *matrix)
> +VISIBLE_IF_KUNIT
> +struct pixel_argb_u16 argb_u16_from_yuv161616(const struct conversion_matrix *matrix,
> +					      u16 y, u16 channel_1, u16 channel_2)
>   {
>   	u16 r, g, b;
>   	s64 fp_y, fp_channel_1, fp_channel_2;
>   	s64 fp_r, fp_g, fp_b;
>   
> -	fp_y = drm_int2fixp(((int)y - matrix->y_offset) * 257);
> -	fp_channel_1 = drm_int2fixp(((int)channel_1 - 128) * 257);
> -	fp_channel_2 = drm_int2fixp(((int)channel_2 - 128) * 257);
> +	fp_y = drm_int2fixp((int)y - matrix->y_offset * 257);
> +	fp_channel_1 = drm_int2fixp((int)channel_1 - 128 * 257);
> +	fp_channel_2 = drm_int2fixp((int)channel_2 - 128 * 257);
 >   >   	fp_r = drm_fixp_mul(matrix->matrix[0][0], fp_y) +
>   	       drm_fixp_mul(matrix->matrix[0][1], fp_channel_1) +
> @@ -310,7 +311,7 @@ VISIBLE_IF_KUNIT struct pixel_argb_u16 argb_u16_from_yuv888(u8 y, u8 channel_1,
>   
>   	return argb_u16_from_u16161616(0xffff, r, g, b);
>   }
> -EXPORT_SYMBOL_IF_KUNIT(argb_u16_from_yuv888);
> +EXPORT_SYMBOL_IF_KUNIT(argb_u16_from_yuv161616);
>   
>   /**
>    * READ_LINE() - Generic generator for a read_line function which can be used for format with one
> @@ -504,8 +505,8 @@ static void semi_planar_yuv_read_line(const struct vkms_plane_state *plane, int
>   	const struct conversion_matrix *conversion_matrix = &plane->conversion_matrix;
>   
>   	for (int i = 0; i < count; i++) {
> -		*out_pixel = argb_u16_from_yuv888(y_plane[0], uv_plane[0], uv_plane[1],
> -						  conversion_matrix);
> +		*out_pixel = argb_u16_from_yuv161616(conversion_matrix, y_plane[0] * 257,
> +						     uv_plane[0] * 257, uv_plane[1] * 257);
>   		out_pixel += 1;
>   		y_plane += step_y;
>   		if ((i + subsampling_offset + 1) % subsampling == 0)
> @@ -549,8 +550,9 @@ static void planar_yuv_read_line(const struct vkms_plane_state *plane, int x_sta
>   	const struct conversion_matrix *conversion_matrix = &plane->conversion_matrix;
>   
>   	for (int i = 0; i < count; i++) {
> -		*out_pixel = argb_u16_from_yuv888(*y_plane, *channel_1_plane, *channel_2_plane,
> -						  conversion_matrix);
> +		*out_pixel = argb_u16_from_yuv161616(conversion_matrix,
> +						     *y_plane * 257, *channel_1_plane * 257,
> +						     *channel_2_plane * 257);
>   		out_pixel += 1;
>   		y_plane += step_y;
>   		if ((i + subsampling_offset + 1) % subsampling == 0) {
> @@ -690,9 +692,9 @@ pixel_read_line_t get_pixel_read_line_function(u32 format)
>   	case DRM_FORMAT_BGRX8888:
>   		return &BGRX8888_read_line;
>   	case DRM_FORMAT_RGB888:
> -		return RGB888_read_line;
> +		return &RGB888_read_line;
>   	case DRM_FORMAT_BGR888:
> -		return BGR888_read_line;
> +		return &BGR888_read_line;

This should be in the previous patch.

Best Regards,
- Maíra