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Date:   Thu, 13 Dec 2018 19:53:04 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc:     Martin Liu <liumartin@google.com>,
        Alan Stern <stern@rowland.harvard.edu>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Daniel Vetter <daniel.vetter@ffwll.ch>
Subject: Re: [PATCH] driver core: Add missing dev->bus->need_parent_lock
 checks
Message-ID: <20181213185304.GB18107@kroah.com>
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On Thu, Dec 13, 2018 at 07:27:47PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> __device_release_driver() has to check dev->bus->need_parent_lock
> before dropping the parent lock and acquiring it again as it may
> attempt to drop a lock that hasn't been acquired or lock a device
> that shouldn't be locked and create a lock imbalance.
> 
> Fixes: 8c97a46af04b (driver core: hold dev's parent lock when needed)
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> 
> This should go into -stable for everything over 4.18 methinks.

Does this fix Daniel's lockdep splat?

thanks,

greg k-h