[Bug 222265] amdgpu: RX 7600 defaults to limited RGB range (washed-out blacks) over HDMI since kernel 7.3.4

[bugzilla-daemon@kernel.org]

https://bugzilla.kernel.org/show_bug.cgi?id=222265

--- Comment #2 from Barto (mister.freeman@laposte.net) ---
### Additional technical findings for bisecting / root cause:
- Simply clearing the `YCbCr 4:4:4` and `YCbCr 4:2:2` capability bits inside
the CTA-861 extension block (while keeping the CTA-861 block intact) does
**not** fix the issue at boot; `amdgpu` still defaults to limited RGB range
(16-235).
- Completely stripping the CTA-861 extension block (reducing the EDID to a
128-byte Base EDID 1.3 block so the driver treats the HDMI output as a DVI-D PC
monitor) immediately restores Full RGB range (0-255) from early KMS boot.
- This points directly to a regression in `amdgpu`'s default HDMI / CTA-861
color format or RGB quantization range selection logic introduced in kernel
7.3.x.

-- 
You may reply to this email to add a comment.

You are receiving this mail because:
You are watching the assignee of the bug.