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From:   Saravana Kannan <saravanak@google.com>
Date:   Fri, 19 Jun 2020 19:32:51 -0700
Message-ID: <CAGETcx87JNfKEu4brQ3S-9wObv=OwXkAoDBSREQH5dAD68TPsA@mail.gmail.com>
Subject: Re: [PATCH v1 4/4] of: platform: Batch fwnode parsing when adding all
 top level devices
To:     Geert Uytterhoeven <geert@linux-m68k.org>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        Len Brown <lenb@kernel.org>,
        Android Kernel Team <kernel-team@android.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
        Ji Luo <ji.luo@nxp.com>,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>
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On Fri, Jun 19, 2020 at 1:07 PM Saravana Kannan <saravanak@google.com> wrote:
>
> I think instead of deferred_probe_work_func() moving the device to the
> end of the dpm_list, I think the device probing successfully is what
> should move it to the end of the dpm_list. That way, the dpm_list is
> actually ordered by when the devices become functional and not the
> random order in DT or random probe order which can get pretty
> convoluted with multiple deferred probes. This feels right and will
> make suspend/resume more robust against DT ordering -- but I'm not
> sure what other wide ranging impact this has for other platforms.

Geert,

If you want to play around with a potential fix to test my hypothesis,
I think it's just adding this one line to driver_bound():
============
klist_add_tail(&dev->p->knode_driver, &dev->driver->p->klist_devices);
device_links_driver_bound(dev);
+device_pm_move_to_tail(dev);

device_pm_check_callbacks(dev);
============

-Saravana