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:   "Michael Kelley (LINUX)" <mikelley@microsoft.com>
To:     Saurabh Sengar <ssengar@linux.microsoft.com>,
        Saurabh Singh Sengar <ssengar@microsoft.com>,
        "drawat.floss@gmail.com" <drawat.floss@gmail.com>,
        "airlied@linux.ie" <airlied@linux.ie>,
        "daniel@ffwll.ch" <daniel@ffwll.ch>,
        "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
        "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] drm/hyperv: Don't overwrite dirt_needed value set by host
Thread-Topic: [PATCH] drm/hyperv: Don't overwrite dirt_needed value set by
 host
Thread-Index: AQHYxrzuab2WaEtpTkGefKGEEbz+BK3sHEIg
Date:   Thu, 22 Sep 2022 22:46:13 +0000
Message-ID: <BYAPR21MB1688F42554CEB542E760F3B5D74E9@BYAPR21MB1688.namprd21.prod.outlook.com>
References: <1662996766-19304-1-git-send-email-ssengar@linux.microsoft.com>
In-Reply-To: <1662996766-19304-1-git-send-email-ssengar@linux.microsoft.com>
Accept-Language: en-US
Content-Language: en-US
msip_labels: MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_ActionId=2cf5fe52-d0b9-4cef-ba0f-c6b727250160;MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_ContentBits=0;MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Enabled=true;MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Method=Standard;MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Name=Internal;MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_SetDate=2022-09-22T22:44:26Z;MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_SiteId=72f988bf-86f1-41af-91ab-2d7cd011db47;
authentication-results: dkim=none (message not signed)
 header.d=none;dmarc=none action=none header.from=microsoft.com;
x-ms-publictraffictype: Email
x-ms-traffictypediagnostic: BYAPR21MB1688:EE_|PH0PR21MB2062:EE_
x-ms-office365-filtering-correlation-id: efcfbc1f-ffe1-46ab-cff4-08da9cec40d7
x-ms-exchange-senderadcheck: 1
x-ms-exchange-antispam-relay: 0
x-microsoft-antispam: BCL:0;
x-microsoft-antispam-message-info: u9+8G1NkrfI9IQQNUbretSnnt3/QjB17xyINgp3nfQdRUCv5RpZmOPW+LvnarPBRn6Y1y3L1/OO8epG/29XJutXT+4TcYy1yCXfjsYTzq1Wc4CrrJUzAvBHSB7vcDLG04icJhE+glfQAoIzWXBjXbQhWe4pra/8UhzSJja5BZCHsyzOLj/Pk5YWDc7ZCaW0TNvaLH7KskhtGvJpnDRb5+q8F/kLkWm5/4As9R5fkeleZWQPWNC5n5bbyxA95CFMNcHeqPSn3Ue1rEkHxTx3xnly7cWAU8kA4+z9Ip16wODlhjvXZhvV6jEu/qFlGLeoCnkrx8I8kOrW9TIMtcExc5QlaKU0Q5WxsTLnoQ9Ufddq+dyhuIKqPIlTHam/s8Bu/EH8nydYzNQWbo11pmuq/VsndDY9L0dmKb8riOSHKApZKpg4UHCA5CC3GO7qFjE01343iBRDwy7J2RnEs8IxsUCCaxSaVMsw7x3deVT4nr5drXZmEbhQ8wiUhms3eUG1+tFC8kNl8WOgUlEOR/hoaqVDXG4YcLOxkwdIpwUwbjhH9eRg7QotgKvTgsPtxyoivzEHcJ3ixt6ISk7GQD+AcaSR4OD0oSIp+3OUP68G25zWIy12zsGH6Ebw1So2uYpTTrk3p2CUJFibfRj32buYo0iwsa56iqUW7qwDVmpwptSqM8FTzrimKooxOJRKrdn8jHaMesBJhuEUGgKlHsBjJ023jiLSOHN4lXUi13p8os/XXY2bAAGh1nUio6nvr8cF42mc3CcU3rj5krHEzL5xHNDX2T/rKa9tCp1JwKLEkwff8vHvfAZGI3dtks9ccuNcU
x-forefront-antispam-report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BYAPR21MB1688.namprd21.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230022)(4636009)(366004)(346002)(396003)(39860400002)(136003)(376002)(451199015)(8990500004)(5660300002)(8676002)(2906002)(41300700001)(71200400001)(33656002)(6506007)(26005)(7696005)(38100700002)(66476007)(9686003)(64756008)(66556008)(66446008)(66946007)(76116006)(8936002)(52536014)(86362001)(316002)(10290500003)(38070700005)(110136005)(478600001)(82960400001)(82950400001)(55016003)(122000001)(186003)(83380400001);DIR:OUT;SFP:1102;
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?ODg912/8dsCA2XdB23dg6BpwH9a58vzCAwNKSlAUsLhXy005evTgfM+rYrFy?=
 =?us-ascii?Q?H7+zSdTH+ocblJLnsNha5RULIyvgKyhu4Jtkc6vj50KDlBpEc6CsqGUkWy6v?=
 =?us-ascii?Q?5dwt0u2C8/MmteGtu6Ie+SJ0vR/ZZpOHrg1sNhpQ37IkSlg2Tjh3R+wKrTa1?=
 =?us-ascii?Q?MX5q7GQff86JRMvObRrUQhBtQQdhDJxZq08QJYzwrw6gpKS+esU393JMza78?=
 =?us-ascii?Q?GQG8xNAApxLZXHu1TNadhvfGjskT229J8qWHBUWzq8WxXa1RBRTKwzLQisnV?=
 =?us-ascii?Q?TCTj9pN7yylXh6rmWZUF/cIeG+IdXwm8ifJhsKNCgMOcFaZQ+QKqzY+64KfK?=
 =?us-ascii?Q?g9FqLz6Bmj8lA2hVkP+qMpYGydIE1KOsjZZTxacPZKD449n+n4rA/5dpbGJV?=
 =?us-ascii?Q?G8KF4IoLrOvWe2M7nvKJxgBVLW69CcQD7fHUDjVdnAeVPcx+7aycd3dfbzJH?=
 =?us-ascii?Q?Ae5Neh/0U8LKrpaLAPR6hMtCJN/QPUmcIpa1gCg9eIne3AIZa3H9GbdlkdR/?=
 =?us-ascii?Q?IcamSi90XmYg7S5Me30FihRAdIKt5XChVO9Hvnx8LuIbQx+asoTUpeItF+ha?=
 =?us-ascii?Q?VZsrhSXR9pSEH18N1WcTGXZIHoog/Cs64E3Qdzb0MvSVFTaMFPKh8AmKqKJn?=
 =?us-ascii?Q?pbuz+VliTNiD5xcXNDyxOWBMZuZs+GBHi7zpLLea5FC1Pz1T07WfcVmbkzHF?=
 =?us-ascii?Q?tUMnnGnPU7qyAV++pmr0254U7FC0DhuZV7DlfHK7MLbvFI9OMLefFV+e7Dtl?=
 =?us-ascii?Q?yrRq2SfJVofRHLJVTGnfblEPqWIiYrZ29AVjcuN4CgJde90uu98xusQTuhg3?=
 =?us-ascii?Q?fE3LHujrKpPsWpAadve86CjEK6YM75cHoCGsJ4YRkDpPQpanxezy1KYdYJlM?=
 =?us-ascii?Q?zCJdyjnpjN8RrPsV4z0mgqseUTDKrBZCY2sR0X+AnnAemtCgijHmJ88vxFr4?=
 =?us-ascii?Q?smi950I2kWXlUtxFOgB2gIIon9yBtrAyVoMGR3F3I4egbDEnyCJUH3VBK1jq?=
 =?us-ascii?Q?18lNWMNPtPYMMzBFgqU0OsuJQybZZUyM9aA5dyH9Ox4QsbKQOYgwG8vHl+Ss?=
 =?us-ascii?Q?QF2ZwGsDC5P1ZhTPQNzRWmvjZT2MtGnlC3PxR/BE2HrcS//cPiD/U3SG0r84?=
 =?us-ascii?Q?OTMYLLNpGTA3N/A0vaCW6ajl+YOlviGLxOck1LWon15g6N/Z4rDAqAvgM2YH?=
 =?us-ascii?Q?Gktp/XKb4bExqpR+yJIschIDqD5CTtjXV7/P7Lyo739mJWU1l2ReMoXJqaVX?=
 =?us-ascii?Q?P0srnIppyDoudgFeiwRvh+GpOOKtMfG2VZO25Th8lFtoUwClg2C2XcVcYI7b?=
 =?us-ascii?Q?RxKZRN9iDIDcbAeaq1KA37qSWOaKjEZ25y/gpMofQ+caBjAYEuuj9nonz0rv?=
 =?us-ascii?Q?jVkqYkJVD1q7WHv3BwklTGrCwyjnIUGgAUL/P6SGJRqbMiYSJvfAL5ODfA6E?=
 =?us-ascii?Q?MCWGvG6UApfJs2xCMvZMaKzQEWYfPuO3/p+vwmgmhLYpAsNoX7zPtH+7AW62?=
 =?us-ascii?Q?ADKjMQnKfzkzu/cH/OhuEXe2SwPZXM4MoEvRSo9Ri+tPDTleBCM3lC4stUHG?=
 =?us-ascii?Q?P331l+kdcR7+boG1N9RQKBAiKmbiokSDx8hvIOa3SX3Nz4By+hnWJCnFRLHA?=
 =?us-ascii?Q?ww=3D=3D?=
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: microsoft.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: BYAPR21MB1688.namprd21.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: efcfbc1f-ffe1-46ab-cff4-08da9cec40d7
X-MS-Exchange-CrossTenant-originalarrivaltime: 22 Sep 2022 22:46:14.0134
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: wjtZWWwBag1WieLsgr7AWmAnw0AjOVqLj7xKVh0HFk+mAz4mhEdYNPnv1Ysip+jJpz2Y1VLkmgLJyrYZmGY4s0+lpkwl/fBMYQAQyEMHs2E=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR21MB2062
X-Spam-Status: No, score=-1.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_SPF_HELO,
        RCVD_IN_DNSWL_NONE,SPF_HELO_PASS,SPF_NONE autolearn=no
        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: Saurabh Sengar <ssengar@linux.microsoft.com> Sent: Monday, September =
12, 2022 8:33 AM
>=20
> Existing code is causing a race condition where dirt_needed value is
> already set by the host and gets overwritten with default value. Remove
> this default setting of dirt_needed, to avoid overwriting the value
> received in the channel callback set by vmbus_open. Removing this
> setting also means the default value for dirt_needed is changed to false
> as it's allocated by kzalloc which is similar to legacy hyperv_fb driver.
>=20
> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
> ---
>  drivers/gpu/drm/hyperv/hyperv_drm_drv.c | 2 --
>  1 file changed, 2 deletions(-)
>=20
> diff --git a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> index 4a8941fa0815..57d49a08b37f 100644
> --- a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> +++ b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> @@ -198,8 +198,6 @@ static int hyperv_vmbus_probe(struct hv_device *hdev,
>  	if (ret)
>  		drm_warn(dev, "Failed to update vram location.\n");
>=20
> -	hv->dirt_needed =3D true;
> -
>  	ret =3D hyperv_mode_config_init(hv);
>  	if (ret)
>  		goto err_vmbus_close;
> --
> 2.31.1

Reviewed-by: Michael Kelley <mikelley@microsoft.com>