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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Thu, 9 Jun 2022 17:56:25 +0200
Message-ID: <CAJZ5v0iDkvg0bK6ywfZCoBfam3hw1Qs3UarJ4MaKLK0rg++cag@mail.gmail.com>
Subject: Re: [PATCH v1 12/16] platform/x86/thinkpad_acpi: Use acpi_dev_for_each_child()
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Linux ACPI <linux-acpi@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Henrique de Moraes Holschuh <hmh@hmh.eng.br>,
        Mark Gross <markgross@kernel.org>,
        ibm-acpi-devel@lists.sourceforge.net,
        Platform Driver <platform-driver-x86@vger.kernel.org>
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On Thu, Jun 9, 2022 at 5:49 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> On Thu, Jun 09, 2022 at 04:09:45PM +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,
> > use acpi_dev_for_each_child() to carry out an action for all of
> > the given ACPI device's children.
>
> ...
>
> > +     rc = acpi_dev_for_each_child(device, tpacpi_evaluate_bcl, NULL);
> > +     if (rc > 0)
> > +             return rc;
> >
> > +     return 0;
>
> It can be simply 'return acpi_dev_for_each_child();', no?

It can.

> AFAICS the caller is prepared for negative returns.

It will not return negative though unless the ACPI tables are horribly broken.