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Date:   Fri, 17 Aug 2018 19:02:39 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     David Hildenbrand <david@redhat.com>
Cc:     Heiko Carstens <heiko.carstens@de.ibm.com>,
        Michal Hocko <mhocko@suse.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
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        David Rientjes <rientjes@google.com>,
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        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Vlastimil Babka <vbabka@suse.cz>, osalvador@suse.de,
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Subject: Re: [PATCH RFC 1/2] drivers/base: export
 lock_device_hotplug/unlock_device_hotplug
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On Fri, Aug 17, 2018 at 01:56:35PM +0200, David Hildenbrand wrote:
> E.g. When adding the memory block devices, we know that there won't be a
> driver to attach to (as there are no drivers for the "memory" subsystem)
> - the bus_probe_device() function that takes the device_lock() could
> pretty much be avoided for that case. But burying such special cases
> down in core driver code definitely won't make locking related to memory
> hotplug easier.

You don't have to have a driver for a device if you don't want to, or
you can just have a default one for all memory devices if you somehow
need it.  No reason to not do this if it makes things easier for you.

thanks,

greg k-h