We recently exposed a "PLANE_CTM" KMS property that allows us to set the R2R color matrix conversion part in the YUV2YUV_WIN pipeline.

We are planning to use this property to emulate a CRTC color conversion matrix, that we want to use for night light: crrev.com/c/1037403

When we enable the RGB2RGB conversion step, the color transformation is applied after a nonlinear to linear gamma conversion, and before a linear to nonlinear conversion.

While this makes sense, it doesn't match what we currently do in the compositor, where we apply the conversion matrix in a nonlinear color space just before outputting the pixel in the fragment shader.

I noticed it is possible to change the gamma mode in YUV2YUV using winX_yuv2yuv_gamma_mode bit, but we'd like to disable it completely.

Is it possible to disable those two steps completely? Can this be achieved specifying an identity gamma LUT via VOP_GAMMA_LUT_ADDR?