Re: [PATCH v1 1/2] usb: core: acpi: Use the sysdev pointer instead of controller device

From: Andy Shevchenko
Date: Tue Apr 26 2022 - 06:33:51 EST

On Mon, Apr 25, 2022 at 3:41 PM Heikki Krogerus
<heikki.krogerus@xxxxxxxxxxxxxxx> wrote:
> The controller device (hcd) does not always have the ACPI
> companion assigned to it at all. We can not rely on it when
> finding the ACPI companion for the root hub. Instead we need
> to use the sysdev pointer here.


> if (!udev->parent) {
> /* root hub is only child (_ADR=0) under its parent, the HC */

I believe the comment can be amended now to point out that we use the
physical device representing the parent of this child, and not
(always) a direct parent of the device in terms of Linux device model.

> - adev = ACPI_COMPANION(udev->dev.parent);
> + adev = ACPI_COMPANION(udev->bus->sysdev);
> return acpi_find_child_device(adev, 0, false);
> }

With Best Regards,
Andy Shevchenko