On Tue, Apr 26, 2022 at 12:18:24PM +0200, Andy Shevchenko wrote:
> 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.
Okay, I'll try to improve the comment.
> > - adev = ACPI_COMPANION(udev->dev.parent);
> > + adev = ACPI_COMPANION(udev->bus->sysdev);
> > return acpi_find_child_device(adev, 0, false);
> > }
thanks,
--
heikki
