Re: [PATCH] drm/vkms: Add YUV410, YUV411, YVU410, and YVU411 support

[Louis Chauvet <louis.chauvet@bootlin.com>]

On 2/2/26 13:14, Louis Chauvet wrote:
> 
> 
> On 2/1/26 15:02, Renjun Wang wrote:
>> Add support for the following planar YUV formats:
>> - DRM_FORMAT_YUV410
>> - DRM_FORMAT_YUV411
>> - DRM_FORMAT_YVU410
>> - DRM_FORMAT_YVU411
>>
>> These formats are handled by the existing planar_yuv_read_line()
>> function, which correctly handles the subsampling defined in each
>> format's drm_format_info.
>>
>> The YVU variants (YVU410, YVU411) are also added to
>> get_conversion_matrix_to_argb_u16() to ensure the U and V columns
>> are swapped correctly in the conversion matrix.
>>
>> Signed-off-by: Renjun Wang <renjunw0@foxmail.com>
> 
> This patch seems correct, so you can add my:
> 
> Acked-by: Louis Chauvet <louis.chauvet@bootlin.com>
 >
> But how did you test it? I don't see the support in IGT. You have an 
> other application / use-case?

I revert my Acked-by for this patch. It looks like the list in 
vkms_config.c wasn’t updated, which means the format won’t be usable by 
userspace.

Could you also add support in IGT so that kms_plane can test it? From 
what I recall, this shouldn’t be much more complex than the VKMS 
implementation—just a few switches to handle the proper conversions.

Thanks,
Louis Chauvet

> Thanks,
> Louis Chauvet
> 
>> ---
>>   drivers/gpu/drm/vkms/vkms_formats.c | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/ 
>> vkms/vkms_formats.c
>> index dfb8e13cba87..5ef5d49a44ef 100644
>> --- a/drivers/gpu/drm/vkms/vkms_formats.c
>> +++ b/drivers/gpu/drm/vkms/vkms_formats.c
>> @@ -730,9 +730,13 @@ pixel_read_line_t 
>> get_pixel_read_line_function(u32 format)
>>       case DRM_FORMAT_P012:
>>       case DRM_FORMAT_P016:
>>           return &YUV161616_semiplanar_read_line;
>> +    case DRM_FORMAT_YUV410:
>> +    case DRM_FORMAT_YUV411:
>>       case DRM_FORMAT_YUV420:
>>       case DRM_FORMAT_YUV422:
>>       case DRM_FORMAT_YUV444:
>> +    case DRM_FORMAT_YVU410:
>> +    case DRM_FORMAT_YVU411:
>>       case DRM_FORMAT_YVU420:
>>       case DRM_FORMAT_YVU422:
>>       case DRM_FORMAT_YVU444:
>> @@ -921,6 +925,8 @@ void get_conversion_matrix_to_argb_u16(u32 format,
>>       memcpy(matrix, matrix_to_copy, sizeof(*matrix_to_copy));
>>       switch (format) {
>> +    case DRM_FORMAT_YVU410:
>> +    case DRM_FORMAT_YVU411:
>>       case DRM_FORMAT_YVU420:
>>       case DRM_FORMAT_YVU422:
>>       case DRM_FORMAT_YVU444:
>