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;
From:   <Tharunkumar.Pasumarthi@microchip.com>
To:     <andriy.shevchenko@linux.intel.com>
CC:     <Kumaravel.Thiagarajan@microchip.com>,
        <linux-kernel@vger.kernel.org>, <linux-serial@vger.kernel.org>,
        <gregkh@linuxfoundation.org>, <jirislaby@kernel.org>,
        <ilpo.jarvinen@linux.intel.com>, <macro@orcam.me.uk>,
        <cang1@live.co.uk>, <colin.i.king@gmail.com>,
        <phil.edworthy@renesas.com>, <biju.das.jz@bp.renesas.com>,
        <geert+renesas@glider.be>, <lukas@wunner.de>,
        <u.kleine-koenig@pengutronix.de>, <wander@redhat.com>,
        <etremblay@distech-controls.com>, <jk@ozlabs.org>,
        <UNGLinuxDriver@microchip.com>
Subject: RE: [PATCH v9 tty-next 2/4] serial: 8250_pci1xxxx: Add driver for
 quad-uart support
Thread-Topic: [PATCH v9 tty-next 2/4] serial: 8250_pci1xxxx: Add driver for
 quad-uart support
Thread-Index: AQHZEKWxJyYrAeLM7kuV3hibr7zg+q5vN+wAgADGUpCAADCNgIAAEWGg
Date:   Fri, 16 Dec 2022 09:30:42 +0000
Message-ID: <PH7PR11MB5958956CB3DFD8E9B4A122379BE69@PH7PR11MB5958.namprd11.prod.outlook.com>
References: <20221216052656.2098100-1-kumaravel.thiagarajan@microchip.com>
 <20221216052656.2098100-3-kumaravel.thiagarajan@microchip.com>
 <Y5tciHzsEGU67h1Z@smile.fi.intel.com>
 <PH7PR11MB5958DF2284FDC67FA7018E9B9BE69@PH7PR11MB5958.namprd11.prod.outlook.com>
 <Y5wrnzLMv5SCWPkn@smile.fi.intel.com>
In-Reply-To: <Y5wrnzLMv5SCWPkn@smile.fi.intel.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?EI46fkD0tK1ASz0VbBQf0AwQbmIgiuEUez7u2hTQ3h0Kp+ehNgC2jdgWfpbv?=
 =?us-ascii?Q?3yGEBSacjlMquNYBLqxQp0OTGBFtyk3ZCOXGdpm/yiLPBu5/gi8XaI+1bwev?=
 =?us-ascii?Q?EHt4p5ZvID+yTs7DLK3I5uvpRoADTv0HFrGil6Ktb6gDn0AQxpuXQyvYXQN0?=
 =?us-ascii?Q?SE0c405qVFlSFOgEcJfcyk3ORC1O7/5bpUiK+7hXbqviZ5mtBlr8bBahjQXa?=
 =?us-ascii?Q?BGI5I1AXKPNLLB147OZkHf4tDaZU6ERwkmWlVPjdXvhitvn295ewCzfVVT58?=
 =?us-ascii?Q?kuQDiw99jrtpiPAKaQrRrgqA0xbvb4lr+5ReOnlEDAuGtCf+RnP7OhdE6S2t?=
 =?us-ascii?Q?GeuPEb9CJpTqubLJ691du5LE3M5kcwQhA4Y59H0eRLQ/MxY5068cqgTV+qNu?=
 =?us-ascii?Q?EgH/YRtqarE7QP9qFCaLyojZQSmE0q+TDlmj1hCO/ULupYSgGoqXoiQmnvgU?=
 =?us-ascii?Q?VU201XqOXW3+omBhiQV4yz3CpY5FJkRLPu5LTup/mBJmb3YUqR/hoYpvfrnf?=
 =?us-ascii?Q?wlyFrPtWU92ft4MjlxgxOjMvb/FBfqJlVAyDi0PCgNGxG6EKJCupzbhh271i?=
 =?us-ascii?Q?SBwydv88Cs+hySvlcu5vji3coNSs9KZ6PI76PRwN4sBIBl0mNxTlWxjPxtFP?=
 =?us-ascii?Q?kNEQgdyHU7pYwufyCfqZaXS/TqCMomhGk/9tfk2zE4TKvu5F1Ygc26WRzpLN?=
 =?us-ascii?Q?itYUYOYOpHvyJ78jZen3/YZDJwilP9SHX6TXKPb5oXWmLcRpwB+haiBdmdvF?=
 =?us-ascii?Q?SIU3DYMh/KBlGpyl2is/r687Od9J59N4TnsipyjYg5n0SnoX2MBlHFysFKs4?=
 =?us-ascii?Q?qxZEvryARuDUz4fLjyej/KU+qKw4ZMn1ytokWY7EPTIoREtsXBz9a+GoHj9o?=
 =?us-ascii?Q?gGUoFPhW5YbdvtGevVpCd5kmTVka+VCAd1iG4XFcXCVoDDz2GD/8ZidEiyGS?=
 =?us-ascii?Q?+fElneMFDW9mvnJhF9YH3WnLTIwO8p8wAT2w5m0hkURwYajOu1DKr9aBNZgg?=
 =?us-ascii?Q?Xmip2OMdDoangVaH1uyqsBmETjECsQ8dNpQO6rqoNRVIjhRNmarycfO+UV0A?=
 =?us-ascii?Q?NpdFNb7sC7UL9PfhoxJz70Titps/CdJ26UeackEtnES01eedIDeA0rVwAP0h?=
 =?us-ascii?Q?waKvCAzHfs7KhNmR+/V+UYQpMCeZWt8bPrA4za0PH3BtMOHSajEgeR/59+/3?=
 =?us-ascii?Q?bbqE0OsQo7WAPE0r3EpiCdkfT8zAqe/xXj7jrhXVHlKJVFJ8Zu4Q3cRU4wjM?=
 =?us-ascii?Q?OzUhZYJQxl1Jiog9GOLfuaFdwBJk8HYOFS8sAj6m4MIryCE4l4RT56AANfDn?=
 =?us-ascii?Q?Kik981WyfnFX2T+sMaQHq4kJGSG1ZbgVbPjV5l5qRZ8Vlhg09ixIZKyOV47o?=
 =?us-ascii?Q?Uz8c/icxPIgffETbGOBK6NTPvk8gibxuMEGGg9gxyucjxSgelqf20V9r+ZHY?=
 =?us-ascii?Q?IluGCxDbxmAMSQ/fK4SzD1P10iXhOZRauRLKkIgljFMIkohGfLKfJRyZdV71?=
 =?us-ascii?Q?nCqI/OzTTGKN0ADi9OvJJGnla+ML17RXDDL1kLvY7SayuTL8F6j+PV1bRQMa?=
 =?us-ascii?Q?y4R0KZrKX7knJl5VUeqUmg5nHiLqHrgHph9aX9Va+U/lAWN46jm4qepsTUPG?=
 =?us-ascii?Q?8RSxRRnFo/AvNeNqHABzB/A=3D?=
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: PH7PR11MB5958.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: e89e2a68-cc81-4395-a5b8-08dadf4833f6
X-MS-Exchange-CrossTenant-originalarrivaltime: 16 Dec 2022 09:30:42.8631
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 3f4057f3-b418-4d4e-ba84-d55b4e897d88
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: xmawf8ycRdaBehKiYtpnF9H/eQVIQP3HgsEQkZgXp8eYPB4HsdcORUgLWF4oxMOH+v0MulPUpOnU6SDAAxlMrGdOtFVzypitMUxyXT+ANAvwTXheIrfLKkb7qhRjmDd9
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL1PR11MB5542
X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

> From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Sent: Friday, December 16, 2022 1:56 PM
> To: Tharunkumar Pasumarthi - I67821
> <Tharunkumar.Pasumarthi@microchip.com>
> Subject: Re: [PATCH v9 tty-next 2/4] serial: 8250_pci1xxxx: Add driver fo=
r
> quad-uart support
>=20
> > > > +             pci_iounmap(pdev, priv->membase);
> > >
> > > Here is inconsistency on how you interpret pci_*() calls when
> > > pcim_enable_device() has been used. I.e. for IRQ you don't
> > > deallocate resources explicitly (yes, it's done automatically
> > > anyway), but you explicitly call pci_iounmap(). Choose a single appro=
ach
> for all of them.
> >
> > AFAIK call to pci_iounmap cannot be avoided since pci_ioremap_bar is no=
t
> 'managed' API.
> > You suggest calling pci_free_irq_vectors (even though it is not mandato=
ry)?
>=20
> Why is it not mandatory?

Hi Andy,

Following is the reason why I felt calling pci_free_irq_vectors is not mand=
atory.
Correct me if my understanding is wrong.

Following is the Callback Sequence (from 6.1 kernel) that gets executed upo=
n calling pci_alloc_irq_vectors:
pci_alloc_irq_vectors =3D>
 pci_alloc_irq_vectors_affinity =3D>
__pci_enable_msi_range =3D>
 pci_setup_msi_context =3D>
 pcim_setup_msi_release =3D>

devm_add_action(&dev->dev, pcim_msi_release, dev);

Inside pcim_msi_release: (called since pcim_enable_device is used)
pci_free_irq_vectors(dev);

From this sequence, it seemed like, kernel takes care of freeing irq and ca=
lling pci_free_irq_vectors is not required.=20

Thanks,
Tharun Kumar P=20