From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM11-DM6-obe.outbound.protection.outlook.com (NAM11-DM6-obe.outbound.protection.outlook.com [40.107.223.52]) by mx.groups.io with SMTP id smtpd.web09.16258.1634055097754390251 for ; Tue, 12 Oct 2021 09:11:38 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@nvidia.com header.s=selector2 header.b=Zrg9tQr7; spf=permerror, err=parse error for token &{10 18 %{i}._ip.%{h}._ehlo.%{d}._spf.vali.email}: invalid domain name (domain: nvidia.com, ip: 40.107.223.52, mailfrom: ashishsingha@nvidia.com) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=YqyZCP4sl74ECaCSHr5WtxN7mewCJNp/JQRRAi5VteMNZSpH1Wufzw2qA+x5OXxFxqbGCTJfSyL1VhXKxv1fq6v7lbFTy+RJaHw8/zvJ32JZMf1fmjMiEcV0x853s7duopF3KE3Es2jvSMBots/6t3GvCXKr2bBsEs0N+unAWlRkLN86/jgkTvjp3Xn2whfXwk+Ut+Dd5Kn5aO9syr/sr3OCIsekvIOGwjBSyDBXqorTDr5aRFTalunVSggwZcdK6enJMCXQN/FuVLChrHZSf1kiwEP9M4SGYRraAI+KtC4NDeK6JYcYFrtU3WkBXjZ9Hss62jNtrCjfVtlT+Smp2w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=7DCpCA4HmloWEOm0J2kq/DJq9jOpvNfow0B3urwxbp8=; b=iGOIEPDH91t/4hkAAt9FuX1OQjHhh6ZFyGGUJLQt9KJfjw8Sk81becThPfFo50vtFm331biGwegQQDpQTHXZAKWjBhVJlbt1hXbjl8kftrhs0PBX+nZKtBdBnaPBeZr345ms855ixNBhugYR2SFYieLZzOB9aNYQsI5bsknJ+hH3FDcZaM/ADvAgpVFs4CSCM63C9qJgbFmAe5saM7ISsCH9THVNZvk2PlX6J62dgACsakorIdL4PD6m+QJh4cXnClbTCgM3fTy3V8kZgZIAc7mz+B+aQE4HYb8Uy4VyCV1/5xDCwKF1vvXWwU+ggx/Xy4cJ2uC7gX2DOUwgH3ru8Q== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=7DCpCA4HmloWEOm0J2kq/DJq9jOpvNfow0B3urwxbp8=; b=Zrg9tQr7LyObcul77NWNoXVmSe5gxH8wHKKdkk+eqb7071NzUJVH8s80erF7q6qsus3o53S748rPG3YA+sQ2N99pW1j4gEpZDyR8T6Sx5BKtgCv4rQir2xAKkDtf9m3qCtZY5GXWI6lqtS8GjSmQwkMAkV9nP9CE9RKVcxGGmJt68ieYSy4QvM9J2dSOgEv3WZAoavdfKUyofUODEHMDGEkFUgVljtXN4Kv5lnRLqiukoVwadhpYrd9foVcFKlLCKluB6dSUkAxX7iswOcoIiZF6VWZ56DvPEOnilUM+dELaWggCpEtK9MohpwCLOzCop4N7nNPjLIEox+WTY5uxWQ== Received: from CO6PR12MB5396.namprd12.prod.outlook.com (2603:10b6:303:139::8) by CO6PR12MB5443.namprd12.prod.outlook.com (2603:10b6:303:13a::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4587.18; Tue, 12 Oct 2021 16:11:36 +0000 Received: from CO6PR12MB5396.namprd12.prod.outlook.com ([fe80::3181:5873:ca0f:cf8b]) by CO6PR12MB5396.namprd12.prod.outlook.com ([fe80::3181:5873:ca0f:cf8b%7]) with mapi id 15.20.4587.026; Tue, 12 Oct 2021 16:11:36 +0000 From: "Ashish Singhal" To: Marc Zyngier , Shanker Donthineni CC: Ard Biesheuvel , edk2-devel-groups-io , Leif Lindholm , Ard Biesheuvel Subject: Re: [PATCH v2] ArmPkg/TimerDxe: Delay End Of Interrupt Signal Thread-Topic: [PATCH v2] ArmPkg/TimerDxe: Delay End Of Interrupt Signal Thread-Index: AQHXvuitkDcYT9ItPUy1xjbmHBblWKvOX7wAgACwtICAAGPiiYAADgyAgAAG55Q= Date: Tue, 12 Oct 2021 16:11:36 +0000 Message-ID: References: <87h7dmpqn2.wl-maz@kernel.org> <87czoap7rg.wl-maz@kernel.org> In-Reply-To: <87czoap7rg.wl-maz@kernel.org> Accept-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: suggested_attachment_session_id: de1a9c08-6d63-0523-e8b1-6c06f6d562be authentication-results: kernel.org; dkim=none (message not signed) header.d=none;kernel.org; dmarc=none action=none header.from=nvidia.com; x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: b4ebac5a-2494-43d0-d2c1-08d98d9af75b x-ms-traffictypediagnostic: CO6PR12MB5443: x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:9508; x-ms-exchange-senderadcheck: 1 x-ms-exchange-antispam-relay: 0 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 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 x-forefront-antispam-report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CO6PR12MB5396.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(366004)(54906003)(6506007)(76116006)(66946007)(91956017)(52536014)(66476007)(508600001)(9686003)(4326008)(64756008)(66446008)(66556008)(55016002)(38070700005)(7696005)(8676002)(316002)(186003)(26005)(8936002)(6636002)(53546011)(110136005)(5660300002)(38100700002)(83380400001)(33656002)(2906002)(71200400001)(86362001)(122000001);DIR:OUT;SFP:1101; x-ms-exchange-antispam-messagedata-chunkcount: 1 x-ms-exchange-antispam-messagedata-0: =?iso-8859-1?Q?gSW/feByWumKOKQFecp8RWrfCXm/hThctxZgPe81zeUCkpj1qi5mgO3oUB?= =?iso-8859-1?Q?nDF1CHrk96ebVxPbkOkun3fsa0ZVELGqd35kJMjplh1D68tgVHHgXzlqrO?= =?iso-8859-1?Q?CUqodW05VZakpxOdTl40kFYyNVQ7b0NRkeSlw0vIHkX2AcodAK/7nhrAEp?= =?iso-8859-1?Q?QF+Ua6SBTYdHWbtna/6zunkNWfi6Uctx9g0pwC9XrvkST8J9Qitvm5w6fz?= =?iso-8859-1?Q?CptaBzsxu8bsd4/VwnMR7M7go3JsoAK/25xhpnQ7Ec4q0vEchGrtfIbyAr?= =?iso-8859-1?Q?TldCe3dzDS84otvAELeTJMRK5m4n0CIklJVXtjvNgSkCECU1OyfjZE8y+6?= =?iso-8859-1?Q?t7nIh5Cd6TosrhmVDi8NDWkX8fma5Gtdn9Cvumaw49TgTLJP0cBACmMYXW?= =?iso-8859-1?Q?VtmtYVO0iS/jcKhGxU/Bhn4arps9ybHqMGyWqkciC0zox0Ebu1KRTE+tXM?= =?iso-8859-1?Q?y4odtwuqwpDcfkWW7B3e72ztRfLBbnxoDrZoy6LohYnWEMM65nKBpq5d/m?= =?iso-8859-1?Q?lH89bj6SCVDf/I7oTMZJG54/M/0uj7rjjOuDnwnlIKxU/ojCve1g39ai0Y?= =?iso-8859-1?Q?Vyait7I9kmLylpE8R5FLVISNXKfghcIfogtWFjUsnRDxHraN23ne7cLteL?= =?iso-8859-1?Q?JLmthgFB2BjES6WrBxfhPpVZPAYcX+unlFPQ6z3rHXwjb/qJp0gB3TY4eP?= =?iso-8859-1?Q?WcmKlbI9FZLMkjyMQGagjbCljD8ZEINEZqPA/rFZOzDaesfUFNibSFTurl?= =?iso-8859-1?Q?YOK0C6vJCRyaYzwxw43fDRLScPS6ra5to2agrVBxG06GdjuX/jbCnoOT07?= =?iso-8859-1?Q?PzIf0mcHtQ8/VKWoUJVLDCCgXJ6AgfoYOK5qILQ7xF+uguB9gKE8K7vZpg?= =?iso-8859-1?Q?IjoJwkkPkNsq0m96lYiNd2lS23FH1NBqcCVog23EEbJgRmGfHDmGKHcuRx?= =?iso-8859-1?Q?ImeYHQJ9+SbJzHuUemWnmb7wFiozfzDaiXw0Wwm8wOUlv4+8+OjS1IdTy7?= =?iso-8859-1?Q?6QEFl/YvPYDrz6ziqLhflDxB7PeAl04WjiOl7YdcVT9TrPMXIkLNZqTxUM?= =?iso-8859-1?Q?WBRdEvsCD/4UBIrgv7gko6Lzv6GfrG1FBKt2vbUXtZVJwEJ/kYKcWn9l3/?= =?iso-8859-1?Q?hcKLKX47jRZRdO3zhWj+0/EXALk/CkZCfXdvK1lnBgvXtKpVhaxhTlx/M1?= =?iso-8859-1?Q?RKMgd9W7wEP3OfMU+CttGx72wqngiD7XwMBtlIJ7ZHqJaEjDgoHoUeY2cn?= =?iso-8859-1?Q?FkHVU4P7ehx9z0Dpo4Nb/A6W1UeQonFSv0u/fCN21cT/YogkB2oufhK0zp?= =?iso-8859-1?Q?VMXNDejgymhfoYTihg1QDvJyOK/9dLBf1ngp5HP7vTDMbWI=3D?= MIME-Version: 1.0 X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: CO6PR12MB5396.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: b4ebac5a-2494-43d0-d2c1-08d98d9af75b X-MS-Exchange-CrossTenant-originalarrivaltime: 12 Oct 2021 16:11:36.2144 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: 4TzSr4PmajlNQsD/gz5/UtshGbsDeMT9/mHJDyAZQphWtoglpLRyN6jFI/Kq0lVK8lbEVG7tu52PmKTbR9qMHw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO6PR12MB5443 Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable =0A= =0A= =0A= From: Marc Zyngier =0A= Sent: Tuesday, October 12, 2021 9:44 AM=0A= To: Ashish Singhal =0A= Cc: Ard Biesheuvel ; edk2-devel-groups-io ; Leif Lindholm ; Ard Biesheuvel =0A= Subject: Re: [PATCH v2] ArmPkg/TimerDxe: Delay End Of Interrupt Signal =0A= =A0=0A= External email: Use caution opening links or attachments=0A= =0A= =0A= Ashish,=0A= =0A= Please don't top post, and please use plain text.=0A= =0A= On Tue, 12 Oct 2021 15:56:58 +0100,=0A= Ashish Singhal wrote:=0A= >=0A= > Marc,=0A= >=0A= > In the document ARM062-1010708621-30 (AArch64 Programmer's Guides=0A= > Generic Timer), towards the end of section 3.4 it says: "When=0A= > writing an interrupt handler for the timers, it is important that=0A= > software clears the interrupt before deactivating the interrupt in=0A= > the GIC. Otherwise, the GIC will re-signal the same interrupt=0A= > again."=0A= =0A= This document is a waste of valuable bits, unfortunately, and isn't an=0A= architecture reference.=0A= =0A= > My change was in accordance with this. We only clear the interrupt=0A= > when we update the compare value but were signaling EOI before that=0A= > going against the guidance in the document.=0A= =0A= There is no such requirement in the GIC architecture, as it makes no=0A= guarantee on how much time it takes for a change of level to be=0A= observed. Given that, this change is pretty much immaterial.=0A= =0A= =A0=A0=A0=A0=A0=A0=A0 M.=0A= =0A= --=0A= Without deviation from the norm, progress is not possible.=0A= =0A= Marc,=0A= =0A= What do you suggest should be the proper fix for getting timer interrupts e= ven when ISTATUS bit is not set? Should we ignore them the way it is in cur= rent implementation? I am OK to file a bug for this if you think that is a = better way to discuss this.=0A= =0A= Shanker,=0A= =0A= Any thoughts on this?=0A= =0A= Thanks=0A= Ashish=