Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Ioana Ciornei <ioana.ciornei@nxp.com>
To:     "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
CC:     Laurentiu Tudor <laurentiu.tudor@nxp.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "netdev-owner@vger.kernel.org" <netdev-owner@vger.kernel.org>,
        Ioana Ciocoi Radulescu <ruxandra.radulescu@nxp.com>,
        Horia Geanta <horia.geanta@nxp.com>,
        Leo Li <leoyang.li@nxp.com>
Subject: RE: [PATCH v3 2/4] bus: fsl-mc: add fsl-mc userspace support
Thread-Topic: [PATCH v3 2/4] bus: fsl-mc: add fsl-mc userspace support
Thread-Index: AQHUgOdDaPiLexuoCUeDRyxH1kY+eaVY3r4AgAAASnA=
Date:   Tue, 20 Nov 2018 16:51:07 +0000
Message-ID: <VI1PR0402MB2800CF10719D11DD21F47356E0D90@VI1PR0402MB2800.eurprd04.prod.outlook.com>
References: <1542728371-6972-1-git-send-email-ioana.ciornei@nxp.com>
 <1542728371-6972-3-git-send-email-ioana.ciornei@nxp.com>
 <20181120164416.GB27531@kroah.com>
In-Reply-To: <20181120164416.GB27531@kroah.com>
Accept-Language: en-US
Content-Language: en-US
received-spf: None (protection.outlook.com: nxp.com does not designate
 permitted sender hosts)
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: 90cd518b-364a-4846-5200-08d64f085e52
X-MS-Exchange-CrossTenant-originalarrivaltime: 20 Nov 2018 16:51:07.8488
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635
X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR0402MB3743
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

> On Tue, Nov 20, 2018 at 03:39:45PM +0000, Ioana Ciornei wrote:
> > +
> > +			error =3D fsl_mc_uapi_create_device_file(mc_bus);
> > +			if (error < 0) {
> > +				error =3D -EPROBE_DEFER;
> > +				goto error_cleanup_msi_domain;
> > +			}
>=20
> What error could occur here that would be somehow fixed if you defer and =
try
> this all again?  Shouldn't you just return the error given (as something =
really went
> wrong here, it's not a "something else needs to start up first issue), an=
d abort?
>=20

It's really a "something else needs to start up first" type of issue. The f=
sl_mc_uapi_create_device_file fails only if the misc_register fails and thi=
s could really happen when the misc char driver is not yet initialized.

Initially, I have used the register_chrdev API and you suggested to use a m=
isc device and just defer probe if it's not yet initialized.

Ioana C


> thanks,
>=20
> greg k-h