Claude review: drm/tegra: gr2d/gr3d: Contain PM in the gr*d_probe/gr*d_remove

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

Patch Review

**Assessment: Good, one typo and one observation.**

This patch does three things in both gr2d.c and gr3d.c:

1. Adds `pm_runtime_enable()`, `pm_runtime_use_autosuspend()`, `pm_runtime_set_autosuspend_delay()` to `gr*d_probe()`.
2. Removes the same three calls from `gr*d_runtime_resume()`.
3. Removes `pm_runtime_dont_use_autosuspend()` and `pm_runtime_force_suspend()` from `gr*d_exit()`.

This is the correct standard pattern. The current code has `pm_runtime_enable()` inside the runtime resume callback, which is architecturally circular — the PM core can only call the runtime resume callback if runtime PM is already enabled. On a second system suspend/resume cycle, `pm_runtime_enable()` gets called again with `disable_depth == 0`, triggering a kernel warning and PM state corruption.

**Typo in commit message:**

> The current power management configuration causes GR2G/GR3D to malfunction after resume.

`GR2G` should be `GR2D`.

**Observation — removal of `pm_runtime_force_suspend()` from `exit()`:**

The patch removes these lines from `gr2d_exit()` / `gr3d_exit()`:
```c
pm_runtime_dont_use_autosuspend(client->dev);
pm_runtime_force_suspend(client->dev);
```

This means during driver teardown, the hardware won't be explicitly suspended by `exit()`. The sequence becomes:
1. `remove()`: `pm_runtime_disable()` — disables PM tracking
2. `remove()`: `host1x_client_unregister()` → triggers `exit()` → frees channels/syncpts/IOMMU
3. devm cleanup releases clocks and resets

Since `pm_runtime_disable()` is called before `exit()`, and `gr*d_runtime_suspend()` won't be invoked (PM is disabled), the channel won't be explicitly stopped via `host1x_channel_stop()` that normally runs in `gr*d_runtime_suspend()`. The clocks and resets are devm-managed so they'll be cleaned up automatically, but skipping `host1x_channel_stop()` during teardown is a behavioral change worth being aware of. In practice this is likely fine since all users have been torn down by this point, but it's worth confirming with the Tegra maintainers.

**Error path:** `pm_runtime_enable()` is placed as the last operation before `return 0` in both probe functions, so there's no failure path that needs a corresponding `pm_runtime_disable()` — this is correct.

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