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From:   Saravana Kannan <saravanak@google.com>
Date:   Mon, 15 Aug 2022 17:43:19 -0700
Message-ID: <CAGETcx_1dDrfrctWMb1rLhZS1Q_hiuQyKBh_1uujE+6S0Fhj2Q@mail.gmail.com>
Subject: Re: boot stuck at starting kernel, due to __genpd_dev_pm_attach?
To:     Colin Foster <colin.foster@in-advantage.com>
Cc:     Pavel Machek <pavel@ucw.cz>, linux-kernel@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Len Brown <len.brown@intel.com>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Kevin Hilman <khilman@kernel.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Geert Uytterhoeven <geert+renesas@glider.be>
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On Mon, Aug 15, 2022 at 5:28 PM Colin Foster
<colin.foster@in-advantage.com> wrote:
>
> On Mon, Aug 15, 2022 at 08:23:07PM +0200, Pavel Machek wrote:
> > Hi!
> >
> > > You might have already gotten this report, but I tried running v6.0-rc1
> > > on my BeagleBone Black and it gets stuck right after "Starting kernel
> > > ..." from U-Boot.
> > >
> > > A bisect pointed me to commit 5a46079a9645 ("PM: domains: Delete usage
> > > of driver_deferred_probe_check_state()").
> > >
> > > I don't have much more detail than that, other than I'm using the
> > > in-tree am335x-boneblack.dts device tree and I believe I had tested with
> > > the multi-v7-defconfig for this verification. I'm happy to test anything
> > > that might offer more information.
> >
> > Well, standart next step is reverting 5a46079a9645 on top of v6.0-rc1,
> > and if it starts working, either you get fix in your inbox, or you ask
> > Linus to revert :-).
>
> I was able to revert 5a46079a9645 and 9cbffc7a5956 and successfully boot
> v6.0-rc1 on the Beaglebone Black.
>
> I still don't know whether the root cause is the patch, or perhaps an
> invalid boneblack DTS. I'll try and dig to get more info about what
> might be failing. But I do think anyone using a Beaglebone will have
> this issue, and I also think I'm not the only using the BBB.
>

Hi Colin,

Thanks for the report. There have been other reports like this. This
commit in question is probably the cause. I have two series going.

One [1] is to revert these patches. Probably more suited for 5.19.xxx releases.

The other [2] is to actually fix the issues you are seeing without
reverting these patches (long term we do want to keep the patch that's
causing the issue for you -- not going into the details here). Can you
give this series[2] a shot and tell me if it fixes the issue? You
might need to pull in this additional diff on top of [2] (I'll roll it
into v2 of the series once I get some tests on this)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 2f012e826986..866755d8ad95 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -2068,7 +2068,11 @@ static int fw_devlink_create_devlink(struct device *con,
                device_links_write_unlock();
        }

-       sup_dev = get_dev_from_fwnode(sup_handle);
+       if (sup_handle->flags & FWNODE_FLAG_NOT_DEVICE)
+               sup_dev = fwnode_get_next_parent_dev(sup_handle);
+       else
+               sup_dev = get_dev_from_fwnode(sup_handle);
+
        if (sup_dev) {
                /*
                 * If it's one of those drivers that don't actually bind to

Thanks,
Saravana

[1] - https://lore.kernel.org/lkml/20220727185012.3255200-1-saravanak@google.com/
[2] - https://lore.kernel.org/lkml/20220810060040.321697-1-saravanak@google.com/