Re: [PATCH] drm/amd/display: Fix BT2020 YCbCr limited range output CSC

Hi Nathan,

Thanks for catching the normalization issue.

I initially used 8-bit normalization because the mode I was debugging was 3840x2160@60 YCbCr 4:4:4 at 8 bpc, and I incorrectly tied the CSC normalization to the output link bit depth. Your 10-bit normalization is correct.

I built and tested your first patch, "[PATCH 1/2] drm/amd/display: fix BT.2020 YCbCr limited output CSC matrix", on Navi33 / DCN 3.2.1 over HDMI to an LG CX with BT.2020/PQ HDR. The limited-range path works correctly with the corrected matrix and fixes the incorrect HDR levels and color I was seeing with the original matrix.

I also confirmed that the resulting amdgpu module contains the corrected limited-range coefficients from that patch. My hardware testing was limited to the DCN limited-range path.

Tested-by: Satyajit Roy [email protected]

Thanks,
Satyajit