Claude review: drm/i915/display: Fix intel_lpe_audio_irq_handler for PREEMPT-RT

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

Patch Review

**Change:**
```c
-	ret = generic_handle_irq(display->audio.lpe.irq);
+	ret = generic_handle_irq_safe(display->audio.lpe.irq);
```

**Analysis:**

- **Correctness:** The fix is correct. `generic_handle_irq()` requires hard IRQ context (per its documentation: "must be called from an IRQ context with irq regs initialized"). On PREEMPT_RT, the i915 interrupt handler is force-threaded, so it runs in process context. `generic_handle_irq_safe()` explicitly handles this by doing `local_irq_save()`/`local_irq_restore()` around the actual handler dispatch (confirmed at `kernel/irq/irqdesc.c:710-712`), making it callable from any context.

- **No functional regression on non-RT:** On non-RT kernels where the handler already runs in hard IRQ context, interrupts are already disabled, so the `local_irq_save()`/`local_irq_restore()` in `generic_handle_irq_safe()` is a no-op — no performance or behavioral difference.

- **Scope:** The change is appropriately minimal. Only this one call site in `intel_lpe_audio_irq_handler()` needs the fix — the caller is the i915 IRQ handler chain, and this is the point where IRQs get forwarded to the LPE audio chained IRQ chip.

- **Commit message:** Accurate and clear. Correctly identifies the PREEMPT_RT threading issue and the Braswell audio platform affected.

**No issues found.** 

Reviewed-by worthy as-is.

---
Generated by Claude Code Patch Reviewer