Claude review: drm/colorop: Add DRM_COLOROP_FIXED_MATRIX

Claude Code Review Bot
2026-04-12T03:07:22Z

Patch Review

**Overall**: Clean UAPI addition. The new colorop type and its initialization follow existing patterns well.

**Issue (minor)**: Kernel-doc tag mismatch. The kdoc comment says `@DRM_COLOROP_FM_YCBCR2020_NC_FULL_RGB` but the actual enum value is `DRM_COLOROP_FM_YCBCR2020_FULL_RGB_NC`:
```c
/**
* @DRM_COLOROP_FM_YCBCR2020_NC_FULL_RGB: // <-- wrong
...
*/
DRM_COLOROP_FM_YCBCR2020_FULL_RGB_NC, // <-- actual name
```
This will generate a kernel-doc warning. The `@` tag must exactly match the symbol name.

**Observation**: The `supported_fm` parameter is `u64` which supports up to 64 fixed matrix types, but `DRM_COLOROP_FM_COUNT` is currently 6. The overflow check `(supported_fm & -BIT(DRM_COLOROP_FM_COUNT)) != 0` is correct.

**Question for discussion**: `DRM_COLOROP_FM_YCBCR_LIMITED_FULL` represents range correction, not a color space conversion matrix. Mixing these two concepts in one enum is workable but may be confusing to userspace. Consider whether this warrants a separate colorop type (though the current approach is pragmatic for hardware that implements both as fixed-function blocks).