Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Anson Huang <anson.huang@nxp.com>
To:     =?iso-8859-1?Q?Uwe_Kleine-K=F6nig?= 
        <u.kleine-koenig@pengutronix.de>
CC:     "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "jslaby@suse.com" <jslaby@suse.com>,
        "shawnguo@kernel.org" <shawnguo@kernel.org>,
        "s.hauer@pengutronix.de" <s.hauer@pengutronix.de>,
        "kernel@pengutronix.de" <kernel@pengutronix.de>,
        "festevam@gmail.com" <festevam@gmail.com>,
        "linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        dl-linux-imx <linux-imx@nxp.com>
Subject: RE: [PATCH] tty: serial: imx: Add return value check for
 platform_get_irq()
Thread-Topic: [PATCH] tty: serial: imx: Add return value check for
 platform_get_irq()
Thread-Index: AQHWJ2R9HRDfI6PXFU6oSAD1fVH3jKiifI2AgAAAUcA=
Date:   Mon, 11 May 2020 07:34:02 +0000
Message-ID: <AM6PR0402MB39112DC95B39E980E830BE34F5A10@AM6PR0402MB3911.eurprd04.prod.outlook.com>
References: <1589180996-618-1-git-send-email-Anson.Huang@nxp.com>
 <20200511072747.2vyavydpfa47kbuy@pengutronix.de>
In-Reply-To: <20200511072747.2vyavydpfa47kbuy@pengutronix.de>
Accept-Language: en-US
Content-Language: en-US
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: 75986d84-dc84-4676-8571-08d7f57dada2
X-MS-Exchange-CrossTenant-originalarrivaltime: 11 May 2020 07:34:02.7431
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: 8XBZ7qO2eMLWG030d4BuqI1pZT1t4yVw/nDxW0FpPJZYnIeh8HvxQGq8zVxcNH7O7fb/mAWeqasbphvIIMHPgQ==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM6PR0402MB3398
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi, Uwe


> Subject: Re: [PATCH] tty: serial: imx: Add return value check for
> platform_get_irq()
>=20
> Hello Anson,
>=20
> On Mon, May 11, 2020 at 03:09:56PM +0800, Anson Huang wrote:
> > RX irq is required, so add return value check for platform_get_irq().
> >
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > ---
> >  drivers/tty/serial/imx.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index
> > f4d6810..f4023d9 100644
> > --- a/drivers/tty/serial/imx.c
> > +++ b/drivers/tty/serial/imx.c
> > @@ -2252,6 +2252,8 @@ static int imx_uart_probe(struct platform_device
> *pdev)
> >  		return PTR_ERR(base);
> >
> >  	rxirq =3D platform_get_irq(pdev, 0);
> > +	if (rxirq < 0)
> > +		return rxirq;
> >  	txirq =3D platform_get_irq_optional(pdev, 1);
> >  	rtsirq =3D platform_get_irq_optional(pdev, 2);
>=20
> I'm not sure we need such a check as devm_request_irq fails if the return=
 value
> of platform_get_irq() is bogus.
>=20
> But if we decide this construct is good enough, the error reporting needs=
 some
> love as currently it emits two error messages which is confusing.

From the driver, the RX IRQ is always required, if it failed in platform_ge=
t_irq(), then the
rest of the code is NOT necessary to be executed, and also I am NOT sure if=
 platform_get_irq()
failed, the devm_request_irq will always failed?

Not very understand about your last question, the platform_get_irq() alread=
y has error message printed
out, so no additional error message is needed in the check. If looking thro=
ugh all other drivers, most
of the platform_get_irq() are having the return value check, if it failed i=
n platform_get_irq(), driver can
just return error from .probe().

Anson