Re: [PATCH 15/24] thunderbolt: Rework control channel to be more reliable

From	Mika Westerberg <mika.westerberg@linux.intel.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 15/24] thunderbolt: Rework control channel to be more reliable
Date	2017-05-25 16:40 +0200
Message-ID	<tL25H-WE-3@gated-at.bofh.it> (permalink)
References	<tIuKR-3YK-5@gated-at.bofh.it> <tIuUy-44c-21@gated-at.bofh.it> <tL0ZZ-iP-23@gated-at.bofh.it>
Organization	Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo

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On Thu, May 25, 2017 at 03:25:46PM +0200, Greg Kroah-Hartman wrote:
> > +/**
> > + * tb_cfg_request_put() - Decrease refcount and possibly release the request
> > + * @req: Request whose refcount is decreased
> > + *
> > + * Call this function when you are done with the request. When refcount
> > + * goes to %0 the object is released.
> > + */
> > +void tb_cfg_request_put(struct tb_cfg_request *req)
> > +{
> > +	kref_put(&req->kref, tb_cfg_request_destroy);
> > +}
> 
> What prevents this call from being called twice on the same object from
> different threads at the same time?  You still need a lock somewhere to
> protect yourself from that, am I just missing where that lock is?

No, you are right - it is missing a lock. I will add it there in the
next version.

Thanks.

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Re: [PATCH 15/24] thunderbolt: Rework control channel to be more  reliable Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-25 15:30 +0200
  Re: [PATCH 15/24] thunderbolt: Rework control channel to be more  reliable Mika Westerberg <mika.westerberg@linux.intel.com> - 2017-05-25 16:40 +0200

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