Claude review: drm/v3d: Clean caches before runtime suspend

[Claude Code Review Bot <claude-review@example.com>]

Patch Review

**Purpose:** Ensure all dirty cache lines are written back to memory before the power domain is shut down, preventing "MMU error from client L2T... pte invalid" on resume.

**Code added in `v3d_power.c:55`:**
```c
v3d_clean_caches(v3d);
```

This is placed after `v3d_irq_disable(v3d)` and before `v3d_suspend_sms(v3d)`.

**Analysis:**
- The placement is correct: IRQs are disabled (no new work can arrive), so the clean is serialized. The clean happens before SMS suspend/clock disable, so the hardware is still accessible.
- `v3d_clean_caches()` takes `v3d->cache_clean_lock`, which serializes against any in-flight flush from `v3d_flush_l2t()`. Since IRQs are disabled and the scheduler should have drained, there shouldn't be contention, but the lock provides safety.
- The Fixes tag correctly points to the runtime PM introduction commit.

**One observation:** The commit message says this directly addresses the "pte invalid" MMU errors. The `Closes:` tags on all three GitHub issues are applied to this patch specifically. But the cover letter says patch 2 "directly addresses the system hangs" and patch 3 "directly addresses the error." Having all three `Closes:` on patch 3 alone seems slightly off — arguably patch 2 is equally important for the fix. However, since patches 2 and 3 work together and will be applied as a series, this is a nit about attribution rather than correctness.

**Verdict: Correct and straightforward.**

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Generated by Claude Code Patch Reviewer