From: Dexuan Cui <decui@microsoft.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Stephen Hemminger <sthemmin@microsoft.com>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        "driverdev-devel@linuxdriverproject.org" 
        <driverdev-devel@linuxdriverproject.org>,
        "Alex Ng (LIS)" <alexng@microsoft.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] Drivers: hv: util: on deinit, don't wait the release
 event, if we shouldn't
Thread-Topic: [PATCH] Drivers: hv: util: on deinit, don't wait the release
 event, if we shouldn't
Thread-Index: AdKQ6tkwTtFdGhZfTFStCsksqVH8PwA07UdhAAAoeIAAAEQ4sAADax9VADKiDSA=
Date: Wed, 1 Mar 2017 14:34:29 +0000
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> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
(c)
> >>> > >     int (*on_msg)(void *, int);         /* callback on new user message */
> >>> >
> >>> > I think we can get away without introducing this new flag, e.g. if we
> >>> > replace release_event with an atomic which will hold the state
> >>> > (open/closed). This will also elimenate possible races above. I can try
> >>> > prototyping a patch if you want me to.
> >>> > --
> >>> >   Vitaly
> >>>
> >>> Thanks for offering the help! Please do. :-)
> >>
> >> BTW, IMO I found another potential issue:
> >> In hvt_op_open -> hvt_reset -> kvp_on_reset(), I think we should call
> >> init_completion() instead of complete()?
> >>
> >
> > To me it looks like we can do better with something different from
> > struct completion, I'll take a look later today.
> 
> Dexuan,
> 
> please take a look at the attached patch. After looking at the code
> again it occured to me that it's going to be easier to move release wait
> to the transport itself. Lightly tested.
> 
>   Vitaly

You made a neat patch, which can fix the bug.

Thank you a lot!

Thanks,
-- Dexuan