Hi Lu Yao, I hit the same bug on a Polaris10 (RX 580) with a TV at 3840x2160@60 in YCbCr 4:2:0, and your patch was the only fix I could find, thank you for posting it.
I have sent a patch that fixes the DTO0 module for HDMI 4:2:0 on DCE 11.2, 11.22 and 12.x, which should cover POLARIS12 too, and leaves ACR (N/CTS) as it is: https://lore.kernel.org/r/[email protected] I could only test Polaris10. If you still have the RX550, a test of that patch on a tree without yours would help a lot. An LLM helped me draft this mail. Thanks, Igor
