Re: [PATCH v1 05/16] USB: ACPI: Use acpi_find_child_by_adr()

Rafael J. Wysocki
2022-06-10T13:14:57Z

On Fri, Jun 10, 2022 at 8:47 AM Heikki Krogerus
<heikki.krogerus@linux.intel.com> wrote:
>
> On Thu, Jun 09, 2022 at 03:56:42PM +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > Instead of walking the list of children of an ACPI device directly
> > in order to find the child matching a given bus address, use
> > acpi_find_child_by_adr() for this purpose.
> >
> > Apart from simplifying the code, this will help to eliminate the
> > children list head from struct acpi_device as it is redundant and it
> > is used in questionable ways in some places (in particular, locking is
> > needed for walking the list pointed to it safely, but it is often
> > missing).
> >
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > ---
> > drivers/usb/core/usb-acpi.c | 9 +--------
> > 1 file changed, 1 insertion(+), 8 deletions(-)
> >
> > Index: linux-pm/drivers/usb/core/usb-acpi.c
> > ===================================================================
> > --- linux-pm.orig/drivers/usb/core/usb-acpi.c
> > +++ linux-pm/drivers/usb/core/usb-acpi.c
> > @@ -127,17 +127,10 @@ out:
> > static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
> > int raw)
> > {
> > - struct acpi_device *adev;
> > -
> > if (!parent)
> > return NULL;
> >
> > - list_for_each_entry(adev, &parent->children, node) {
> > - if (acpi_device_adr(adev) == raw)
> > - return adev;
> > - }
> > -
> > - return acpi_find_child_device(parent, raw, false);
> > + return acpi_find_child_by_adr(parent, raw);
> > }
> >
> > static struct acpi_device *
>
> I think usb_acpi_find_port() can also be dropped now.

Yes, it can.

I'm dropping it in the new version of the patch to be posted.