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From:   Saravana Kannan <saravanak@google.com>
Date:   Fri, 27 Mar 2020 11:30:59 -0700
Message-ID: <CAGETcx-J+TP+0NsOe75Uu3Q8K6=qYja6eDbjNH2764QV53=nMA@mail.gmail.com>
Subject: Re: [RFC PATCH v1] driver core: Set fw_devlink to "permissive"
 behavior by default
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Marek Szyprowski <m.szyprowski@samsung.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        Android Kernel Team <kernel-team@android.com>,
        LKML <linux-kernel@vger.kernel.org>
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On Fri, Mar 27, 2020 at 8:21 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Fri, Mar 27, 2020 at 11:25:48AM +0100, Marek Szyprowski wrote:
> > Hi,
> >
> > On 2020-03-21 22:03, Saravana Kannan wrote:
> > > Set fw_devlink to "permissive" behavior by default so that device links
> > > are automatically created (with DL_FLAG_SYNC_STATE_ONLY) by scanning the
> > > firmware.
> > >
> > > This ensures suppliers get their sync_state() calls only after all their
> > > consumers have probed successfully. Without this, suppliers will get
> > > their sync_state() calls at late_initcall_sync() even if their consuer
> > >
> > > Ideally, we'd want to set fw_devlink to "on" or "rpm" by default. But
> > > that needs more testing as it's known to break some corner case
> > > drivers/platforms.
> > >
> > > Cc: Rob Herring <robh+dt@kernel.org>
> > > Cc: Frank Rowand <frowand.list@gmail.com>
> > > Cc: devicetree@vger.kernel.org
> > > Signed-off-by: Saravana Kannan <saravanak@google.com>
> >
> > This patch has just landed in linux-next 20200326. Sadly it breaks
> > booting of the Raspberry Pi3b and Pi4 boards, either in 32bit or 64bit
> > mode. There is no warning nor panic message, just a silent freeze. The
> > last message shown on the earlycon is:
> >
> > [    0.893217] Serial: 8250/16550 driver, 1 ports, IRQ sharing enabled

Marek,

Any chance you could get me a stack trace for when it's stuck? That'd
be super helpful and I'd really appreciate it. Is it working fine on
other variants of Raspberry?

>
> I've just reverted this for now.
>

Greg,

I have no problem with reverting this. If there's any other
tree/branch you can put this on where it could get more testing and
reporting of issues, that'd be great.

-Saravana