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Date:   Wed, 25 Mar 2020 10:17:34 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Davide Caratti <dcaratti@redhat.com>
Cc:     Saravana Kannan <saravanak@google.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Vladimir Benes <vbenes@redhat.com>, kernel-team@android.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 3/3] driver core: Skip unnecessary work when device
 doesn't have sync_state()
Message-ID: <20200325091734.GA3073501@kroah.com>
References: <20200221080510.197337-1-saravanak@google.com>
 <20200221080510.197337-4-saravanak@google.com>
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On Wed, Mar 25, 2020 at 10:11:19AM +0100, Davide Caratti wrote:
> On Wed, 2020-03-25 at 08:44 +0100, Greg Kroah-Hartman wrote:
> > On Tue, Mar 24, 2020 at 09:03:28PM +0100, Davide Caratti wrote:
> > > On Fri, 2020-02-21 at 00:05 -0800, Saravana Kannan wrote:
> > > > A bunch of busy work is done for devices that don't have sync_state()
> > > > support. Stop doing the busy work.
> > > > 
> > > > Signed-off-by: Saravana Kannan <saravanak@google.com>
> > > > ---
> > > >  drivers/base/core.c | 4 +++-
> > > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > > > 
> > > 
> > > hello Greg,
> > > 
> > > this patch and patch 2/3 of the same series proved to fix systematic
> > > crashes (NULL pointer dereference in device_links_flush_sync_list() while
> > > loading mac80211_hwsim.ko, see [1]) on Fedora 31, that are triggered by
> > > NetworkManager-ci [2]. May I ask to queue these two patches for the next
> > > 5.5 stable?
> > 
> > What are the git commit ids of these patches in Linus's tree that you
> > want backported?
> 
> right, I should have mentioned them also here: 
> 
> ac338acf514e "(driver core: Add dev_has_sync_state())" <-- patch 2/3 
> 77036165d8bc "(driver core: Skip unnecessary work when device doesn't have sync_state())" <-- patch 3/3
> 
> like Saravana mentioned, the problem is probably introduced by patch
> 1/3 of the series, 
> 
> 77036165d8bc "(driver core: Skip unnecessary work when device doesn't have sync_state())"
> 
> that's already in stable 5.5.

Now queued up, thanks!

greg k-h