Re: [PATCH] device probe: add self triggered delayed work request

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From	Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] device probe: add self triggered delayed work request
Date	Mon, 08 Aug 2016 12:50:01 +0200
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Hi Qing,

I suspect there is potential dead-lock with this patch:

cpu0                                                    cpu1

driver_deferred_probe_add                               deferred_probe_work_func
 ...                                                     mutex_unlock(&deferred_probe_mutex)
 mutex_lock(&deferred_probe_mutex)                        bus_probe_device(dev)
  ...                                                      device return -EPROBE_DEFER
  ...                                                       driver_deferred_probe_add
  ...                                                        mutex_lock(&deferred_probe_mutex)
  ...                                                         <deadlock!>
  cancel_delayed_work(&deferred_probe_trigger_work)
   <work will never end - deadlock!>

Please confirm if this scenario is possible.

BR, Shamir Rabinovitch

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Re: [PATCH] device probe: add self triggered delayed work request Shamir Rabinovitch <shamir.rabinovitch@oracle.com> - 2016-08-08 12:50 +0200
  Re: [PATCH] device probe: add self triggered delayed work request Qing Huang <qing.huang@oracle.com> - 2016-08-09 02:10 +0200
    Re: [PATCH] device probe: add self triggered delayed work request Shamir Rabinovitch <shamir.rabinovitch@oracle.com> - 2016-08-09 12:20 +0200
      Re: [PATCH] device probe: add self triggered delayed work request Qing Huang <qing.huang@oracle.com> - 2016-08-09 23:00 +0200

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