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Date:   Thu, 30 Jul 2020 08:54:06 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Lukas Wunner <lukas@wunner.de>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Dan Williams <dan.j.williams@intel.com>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Pantelis Antoniou <pantelis.antoniou@konsulko.com>,
        Alexander Duyck <alexander.h.duyck@linux.intel.com>,
        Mark Brown <broonie@kernel.org>, linux-kernel@vger.kernel.org,
        linux-spi@vger.kernel.org
Subject: Re: [PATCH 0/3] Fix races on device removal
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On Wed, Jul 08, 2020 at 03:27:00PM +0200, Lukas Wunner wrote:
> Prevent dynamic SPI device addition below a controller which is
> being removed.  To do so, set the controller's "dead" flag using
> kill_device() (patch [3/3]).

Why is the SPI bus allowing this to happen?  Don't you have a per-bus
lock that can serialize all of this?

thanks,

greg k-h