Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Fri, 11 Aug 2023 14:38:21 +0200
From:   Miquel Raynal <miquel.raynal@bootlin.com>
To:     Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        Robert Marko <robert.marko@sartura.hr>,
        Luka Perkov <luka.perkov@sartura.hr>,
        Michael Walle <michael@walle.cc>, linux-kernel@vger.kernel.org,
        Randy Dunlap <rdunlap@infradead.org>,
        Chen-Yu Tsai <wenst@chromium.org>,
        Daniel Golle <daniel@makrotopia.org>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <rafal@milecki.pl>
Subject: Re: [PATCH v9 1/7] nvmem: core: Create all cells before adding the
 nvmem device
Message-ID: <20230811143821.29cf335a@xps-13>
In-Reply-To: <154883fc-a6bc-01a9-b044-dac8848e9963@linaro.org>
References: <20230808062932.150588-1-miquel.raynal@bootlin.com>
        <20230808062932.150588-2-miquel.raynal@bootlin.com>
        <b49f8d07-9de9-48b5-27bd-fce02a82c515@linaro.org>
        <20230808092433.039e2f48@xps-13>
        <05aea50f-6692-962e-abe7-765197815f03@linaro.org>
        <20230811141122.7921df1d@xps-13>
        <154883fc-a6bc-01a9-b044-dac8848e9963@linaro.org>
Organization: Bootlin
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Hi Srinivas,

srinivas.kandagatla@linaro.org wrote on Fri, 11 Aug 2023 13:26:24 +0100:

> On 11/08/2023 13:11, Miquel Raynal wrote:
>=20
> >>
> >> =20
> >=20
> > nvmem_register() calls device_initialize() and later device_add(),
> > which is exactly the content of device_register(). Upon error
> > after device_add(), we currently call device_put(), whereas
> > device_unregister would call both device_del() and device_put().
> >=20
> > I would expect device_del() to be first called upon error before
> > device_put() *after* device_add() has succeded, no? =20
>=20
> That is correct afaiu, if device_add is succeed we need to call device_de=
l(). As the patch now moved the device_add to end of function we really do =
not need device_del() in err path.

Right, I'm looking at the end of the series where I need to add
device_del() in the error path because something gets added after
device_add(). So we are aligned, thanks for the feedback.

> >>> I also see the layout_np below should be freed before jumping in the
> >>> error section. =20
> >>
> >> you mean missing of_node_put()? =20
> >=20
> > Yes, I need to call of_node_put() before jumping into the error path. =
=20
>=20
> Are we not already doing it in nvmem_layout_get() and nvmem_add_cells_fro=
m_fixed_layout() ?

We perform the layout_get for two reasons:
- knowing if there is a layout
- using the layout
Here we are in the first case, and we don't want to retain a reference
from here. Only in the second case.

Thanks,
Miqu=C3=A8l