Re: [RFC PATCH 1/5] drm/xe/pm: add xe_pm_pme_supported() helper

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 17 Aug 2026, Vinod Govindapillai <vinod.govindapillai@intel.com> wrote:
> Introduce the helper to check if the device can signal a wakeup event
> while runtime suspended. This can avoid scheduling the HPD polling.
>
> Assisted-by: GitHub_Copilot:claude-opus-5
> Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_pm.c | 21 +++++++++++++++++++++
>  drivers/gpu/drm/xe/xe_pm.h |  1 +
>  2 files changed, 22 insertions(+)
>
> diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
> index a5289a9df8d2..635bfb1c7f78 100644
> --- a/drivers/gpu/drm/xe/xe_pm.c
> +++ b/drivers/gpu/drm/xe/xe_pm.c
> @@ -937,6 +937,27 @@ bool xe_pm_runtime_resume_and_get(struct xe_device *xe)
>  	return pm_runtime_resume_and_get(xe->drm.dev) >= 0;
>  }
>  
> +/**
> + * xe_pm_pme_supported - Can the device signal PME from its suspend target state?
> + * @xe: xe device instance
> + *
> + * Determine whether the device can generate a Power Management Event while
> + * runtime suspended.
> + *
> + * Return: true if PME is supported from the target state, false otherwise.
> + */
> +bool xe_pm_pme_supported(struct xe_device *xe)
> +{
> +	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
> +
> +	/*
> +	 * pci_dev_run_wake() checks dev->pme_support, verifies
> +	 * pci_pme_capable() against the state pci_target_state() picks, and
> +	 * walks upstream to confirm the wake can actually be routed.

Is this comment helpful? pci_dev_run_wake() has a kernel-doc comment
that explains what it does?

> +	 */
> +	return pci_dev_run_wake(pdev);
> +}
> +
>  /**
>   * xe_pm_assert_unbounded_bridge - Disable PM on unbounded pcie parent bridge
>   * @xe: xe device instance
> diff --git a/drivers/gpu/drm/xe/xe_pm.h b/drivers/gpu/drm/xe/xe_pm.h
> index 6d5ab09cb769..16b8699e59ec 100644
> --- a/drivers/gpu/drm/xe/xe_pm.h
> +++ b/drivers/gpu/drm/xe/xe_pm.h
> @@ -30,6 +30,7 @@ bool xe_pm_runtime_get_if_active(struct xe_device *xe);
>  bool xe_pm_runtime_get_if_in_use(struct xe_device *xe);
>  void xe_pm_runtime_get_noresume(struct xe_device *xe);
>  bool xe_pm_runtime_resume_and_get(struct xe_device *xe);
> +bool xe_pm_pme_supported(struct xe_device *xe);
>  void xe_pm_assert_unbounded_bridge(struct xe_device *xe);
>  int xe_pm_set_vram_threshold(struct xe_device *xe, u32 threshold);
>  void xe_pm_d3cold_allowed_toggle(struct xe_device *xe);

-- 
Jani Nikula, Intel