|SUCCESS| [v2] dmadev: clarify last_idx documentation for completion APIs

[dpdklab at iol.unh.edu]

Test-Label: ai-code-review
Test-Status: SUCCESS
https://dpdk.org/patch/166735

_AI Code Review_

=== Patch Review: series.patch (via Claude) ===
Review date: 2026-07-15

# DPDK Patch Review

## Summary
This patch clarifies the documentation for the `last_idx` parameter in dmadev completion APIs. The changes are documentation-only and correctly describe the semantic differences between `rte_dma_completed()` and `rte_dma_completed_status()`.

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## Detailed Review

### Correctness
No correctness issues found. This is a documentation-only change with no code modifications.

### API and Documentation

**Info:** The clarifications are accurate and helpful:

1. `rte_dma_completed()`: Correctly clarifies that `last_idx` refers to the last *successfully* completed operation, and that it stops at the first error.

2. `rte_dma_completed_status()`: Correctly clarifies that `last_idx` refers to the last operation reported regardless of success/failure status.

3. Both descriptions appropriately note that only up to `nb_cpls` operations are reported, so `last_idx` may not represent the device's true completion point.

The documentation now properly distinguishes between the two functions' behavior regarding error handling.

### C Coding Style
Not applicable - this patch contains only documentation changes.

### Process Compliance
-  Fixes tag present and correctly formatted
-  Signed-off-by present
-  Changes are atomic (single logical change)
-  Version history included in commit message (v2 notes)
-  No release notes required (documentation clarification only)

### Forbidden Tokens
Not applicable - no code changes.

### Structure
-  Single file modified appropriately
-  Changes are minimal and focused
-  Documentation matches the actual API behavior (based on the description provided)

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## Conclusion

**No issues found.**

This is a clean documentation improvement patch that removes ambiguity in the API documentation and correctly describes the semantic differences between the two completion APIs. The clarifications are valuable for API users and the patch follows DPDK guidelines.