Re: [PATCH 2/8] ACPI: PM: Use the new device_to_pm() helper to access struct dev_pm_ops

Rafael J. Wysocki
2020-05-26T08:37:57Z

On Mon, May 25, 2020 at 8:26 PM Krzysztof Wilczyński <kw@linux.com> wrote:
>
> Use the new device_to_pm() helper to access Power Management callbacs
> (struct dev_pm_ops) for a particular device (struct device_driver).
>
> No functional change intended.
>
> Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
> ---
> drivers/acpi/device_pm.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
> index 5832bc10aca8..b98a32c48fbe 100644
> --- a/drivers/acpi/device_pm.c
> +++ b/drivers/acpi/device_pm.c
> @@ -1022,9 +1022,10 @@ static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev)
> int acpi_subsys_prepare(struct device *dev)
> {
> struct acpi_device *adev = ACPI_COMPANION(dev);
> + const struct dev_pm_ops *pm = driver_to_pm(dev->driver);

I don't really see a reason for this change.

What's wrong with the check below?

>
> - if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {
> - int ret = dev->driver->pm->prepare(dev);
> + if (pm && pm->prepare) {
> + int ret = pm->prepare(dev);
>
> if (ret < 0)
> return ret;
> --
> 2.26.2
>