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From:   Dmitry Rokosov <DDRokosov@sberdevices.ru>
To:     Jonathan Cameron <jic23@kernel.org>
CC:     "robh+dt@kernel.org" <robh+dt@kernel.org>,
        "lars@metafoo.de" <lars@metafoo.de>,
        "andy.shevchenko@gmail.com" <andy.shevchenko@gmail.com>,
        "noname.nuno@gmail.com" <noname.nuno@gmail.com>,
        "linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>,
        kernel <kernel@sberdevices.ru>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH v1] iio: trigger: move trig->owner init to trigger
 allocate() stage
Thread-Topic: [RFC PATCH v1] iio: trigger: move trig->owner init to trigger
 allocate() stage
Thread-Index: AQHYdd/Pt2zXEFx7c0Or/RCut5+rEK0/GLKAgCpM/oA=
Date:   Fri, 1 Jul 2022 11:59:59 +0000
Message-ID: <20220701115823.vywhifktaxcr72cc@CAB-WSD-L081021.sigma.sbrf.ru>
References: <20220601174837.20292-1-ddrokosov@sberdevices.ru>
 <20220604145955.2a1108ca@jic23-huawei>
In-Reply-To: <20220604145955.2a1108ca@jic23-huawei>
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Hello Jonathan,

This patch has been on the mailing list for one month already, but no
comments from other IIO reviewers. What do you think we should do with it?
Is it a helpful change or not?

On Sat, Jun 04, 2022 at 02:59:55PM +0100, Jonathan Cameron wrote:
> On Wed, 1 Jun 2022 17:48:32 +0000
> Dmitry Rokosov <DDRokosov@sberdevices.ru> wrote:
>=20
> > To provide a new IIO trigger to the IIO core, usually driver executes t=
he
> > following pipeline: allocate()/register()/get(). Before, IIO core assig=
ned
> > trig->owner as a pointer to the module which registered this trigger at
> > the register() stage. But actually the trigger object is owned by the
> > module earlier, on the allocate() stage, when trigger object is
> > successfully allocated for the driver.
> >=20
> > This patch moves trig->owner initialization from register()
> > stage of trigger initialization pipeline to allocate() stage to
> > eliminate all misunderstandings and time gaps between trigger object
> > creation and owner acquiring.
> >=20
> > Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
>=20
> Hi Dmitry,
>=20
> I 'think' this is fine, but its in the high risk category that I'd like
> to keep it on list for a few weeks before applying.
>=20
> Note I'm still keen that in general we keep the flow such that
> we do allocate()/register()/get() as there is no guarantee that the get()
> will never do anything that requires the trigger to be registered, even
> though that is true today.  Which is another way of saying I'm still
> keen we fix up any cases that sneak in after your fix up set dealt with
> the current ones.
>=20
> Thanks for following up on this!
>=20
> Jonathan
>=20

--=20
Thank you,
Dmitry=