Claude review: Add support for DisplayPort link training information report

Claude Code Review Bot
2026-04-12T00:51:23Z

Overall Series Review

Subject: Add support for DisplayPort link training information report
Author: Kory Maincent <kory.maincent@bootlin.com>
Patches: 18
Reviewed: 2026-04-12T10:51:23.842996

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This is a 12-patch RFC series introducing a generic DRM framework for exposing DisplayPort link training state to userspace via connector properties. The approach is structurally sound and addresses a real gap -- DP link parameters are currently only accessible through driver-specific debugfs, with no standard interface.

The series is organized into three phases: bugfixes (1-3), i915 drmm conversion (4-8), and the new DP connector framework + driver adoption (9-12). The structural decomposition is sensible.

**Key concerns:**

1. **No userspace notification mechanism.** Properties are updated via `drm_object_property_set_value()` which does not generate a uevent. Userspace has no way to know when link training completes or values change -- it must poll. This fundamentally limits the usefulness of the feature and should be addressed in the design.

2. **Bitmask semantics are confusing.** The same bitmask property type is used both for capabilities (supported values) and runtime state (current value). Setting `nlanes` to `BIT(1)` to mean "2 lanes active" is unintuitive. An enum property for current state and a bitmask for capabilities would be clearer.

3. **Several bugs in the driver adoption patches** (10, 12), including uninitialized stack variables, unchecked return values, and an ops overwrite bug.

4. **The i915 drmm conversion (patches 4-8) is large and largely AI-generated** ("Assisted-by: Claude Code"). While the approach is correct, this is safety-critical code (resource lifetime management) that needs careful per-platform testing before merging.

5. **Missing UAPI documentation.** New connector properties visible to userspace should be documented and ideally have IGT test coverage.

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Generated by Claude Code Patch Reviewer