Claude review: drm/imagination: Access FW initialised state with READ/WRITE_ONCE

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Patch Review

**Verdict: Reasonable, minor question**

Using `READ_ONCE`/`WRITE_ONCE` for `fw_dev->initialised` is appropriate since this bool is accessed from multiple contexts (IRQ handler, watchdog worker, suspend/resume, init/fini) without a common lock. This prevents compiler optimizations like repeated loads or store tearing.

The changes are straightforward and mechanical.

**Minor note:** `READ_ONCE`/`WRITE_ONCE` alone do not guarantee ordering with respect to the operations that the `initialised` flag guards. For example, in `pvr_fw_init()`:

```c
WRITE_ONCE(fw_dev->initialised, true);
```

There's no barrier ensuring that the FW initialization steps are visible to other CPUs before `initialised` becomes `true`. If ordering matters (i.e., if another CPU could check `initialised` and then access FW structures), a `smp_store_release()`/`smp_load_acquire()` pair would be more appropriate. The commit message says "ensure atomicity of operation" — but `READ_ONCE`/`WRITE_ONCE` don't provide atomicity guarantees in the hardware sense; they just prevent compiler issues. Worth clarifying the intent.

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