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From:   "Rafael J. Wysocki" <rjw@rjwysocki.net>
To:     Linux ACPI <linux-acpi@vger.kernel.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>
Subject: [PATCH v2 00/16] ACPI: Get rid of the list of children in struct acpi_device
Date:   Mon, 13 Jun 2022 20:03:25 +0200
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References: <1843211.tdWV9SEqCh@kreacher>
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On Thursday, June 9, 2022 3:44:27 PM CEST Rafael J. Wysocki wrote:
> Hi All,
> 
> Confusingly enough, the ACPI subsystem stores the information on the given ACPI
> device's children in two places: as the list of children in struct acpi_device
> and (as a result of device registration) in the list of children in the embedded
> struct device.
> 
> These two lists agree with each other most of the time, but not always (like in
> error paths in some cases), and the list of children in struct acpi_device is
> not generally safe to use without locking.  In principle, it should always be
> walked under acpi_device_lock, but in practice holding acpi_scan_lock is
> sufficient for that too.  However, its users may not know whether or not
> they operate under acpi_scan_lock and at least in some cases it is not accessed
> in a safe way (note that ACPI devices may go away as a result of hot-remove,
> unlike OF nodes).
> 
> For this reason, it is better to consolidate the code that needs to walk the
> children of an ACPI device which is the purpose of this patch series.
> 
> Overall, it switches over all of the users of the list of children in struct
> acpi_device to using helpers based on the driver core's mechanics and finally
> drops that list, but some extra cleanups are done on the way.
> 
> Please refer to the patch changelogs for details.

Here's a v2 of this series, mostly addressing review comments, but the subjects
of the Thunderbolt and USB patches have been changed too.

Thanks!