From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from SA9PR02CU001.outbound.protection.outlook.com (mail-southcentralusazon11013042.outbound.protection.outlook.com [40.93.196.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9B0CF37AA9C; Fri, 28 Aug 2026 17:07:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.93.196.42 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787936835; cv=fail; b=aqHFzv/HvjVaW0DR8wPRJXCYQ6FKkiKTbtoEm6Ay5GcBOaZA9N5i4GU8duS0paMUlZ5PFX/aa19MEyPjYaYOvVJUxqPfF3FuwjdDVpzYZdTR3cS2Z2ILtQEiaU4Ir9bt2o3ponyeQ6Vhnr6snoAXOaCpGPBKqTV3jDHVVus6UDI= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787936835; c=relaxed/simple; bh=YCQKyn84Cft8dKunNYycAKIzFO7dyHk5ESIOhWwH67Y=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=Zr15IFFPHllxrGKnjAolHSefA7gEVV1wE44R/UUjBPa2BieIiaKXLAcUDepQsDIUmrhkx/8EToADwXpUATr9RPDl2H5oxf3Gsz8TN94wCKxAUcJFEAiQeCyfCD3+vKk4tp04f81CmhZjaLjL4O6H2UVauuV3bIQpdKWGAI2voXU= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=YhNshMXX; arc=fail smtp.client-ip=40.93.196.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="YhNshMXX" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=yX5GKjRZaNoFqlBEOIY+U+dFxdPB5ZfNkfwfEQYdEBU+y1zIcsZ31NhGDvf3vc4H1cF7LhD76eLY4ykDKDWk/xMcRZiBvovj0WkKz75m3Xg+HzUKXqU01gRQDoCs6GOV/7j7yaIwN2Pz3RyCZrrET1DnLts7a3P1FqF6WNgXn2uat0EGAEGoV2IEGWRSW7iBjeP7uuGUxEMRBq6zOPz2/s4VTR23fDqYQgEcrN8ie8Le+VklVhr1CVaVTy1bg87lO+qNXBnf2dv++z/OYZpgYJ8q6T4oQWBnLr4bLbtupekNHejwy/PB/rVDAV/9RykCRPc7yBFazOjCtFxqxXbEgQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=83p7jdO2VEUXzIiQ67WkCOz2qEys4Gzg/qmYb0FRtV4=; b=lu6qdcG6IVZ1/VzE1BYGxPKF4tu39WsASY9r9G40h594RxK7u+00s7Y+fK7Y3tPVe2WOeHtynPTt6nJ8NxZgx2ZvxxNdF6v1qBpvGy0MAfyXvcPBPRruZZ0Jx7b8Ped7pPtLuZ95dmxPJ/oKewCCzeogQyfQuQC1hezxK9VBoS4gMJdrk89/CNEv87CYCDLBuJlJ8A6m/oALdTdUk6t6TmwELToFHvh8PPrRFuSf+Ih+1xhVAH8PP4mLXrHXnMNnLa88IoLm0W04q51NZioaVGkP4YQpqp3om7p7UP3PUPt0CulCHiZIckv2xVhHSiJV/PLMr+LZBYwuJY8qmMziVg== 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=83p7jdO2VEUXzIiQ67WkCOz2qEys4Gzg/qmYb0FRtV4=; b=YhNshMXXUp2uvJIWZOuoe0VRb1XS5i4B3AiOp6dA6YsZvdTzMnEm0JkkQaRm/FZSmH5L+/qeF1twnXq264m6AWA+/eMXg8ntDLd1DYLnJE8JjvNRXPVZa9tgNOMngXRkPfbl2u1Y5nGaZ4ys743WR9wIP/XyjMuz4ZgY1qC5lkzWMXFZe/MnPV7p1oJEg4twyFK2UAB4XLHaOCBDs0gGYQDGlGRotFjBpIuyCGj7rKya1SM+xGo1MhH9p7waxxDINVeDufGGWgz+jwkUvf6KnPfLqDqfH/TxTdbytztQ8lZu4JnXFed1as/oPm4BU8YW2RXO2u85P6GIXyhXf0KDig== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from SJ1PR12MB6051.namprd12.prod.outlook.com (2603:10b6:a03:48a::18) by IA1PR12MB8309.namprd12.prod.outlook.com (2603:10b6:208:3fe::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.360.11; Fri, 28 Aug 2026 17:06:58 +0000 Received: from SJ1PR12MB6051.namprd12.prod.outlook.com ([fe80::96e1:b300:7b78:d3a9]) by SJ1PR12MB6051.namprd12.prod.outlook.com ([fe80::96e1:b300:7b78:d3a9%6]) with mapi id 15.21.0360.008; Fri, 28 Aug 2026 17:06:57 +0000 Message-ID: <0c2c424f-0372-4626-b14e-7697d98e6b20@nvidia.com> Date: Fri, 28 Aug 2026 18:06:50 +0100 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH tty 1/1] serial: 8250: Change console_msr_work to IRQ_WORK_LAZY To: Sebastian Andrzej Siewior , John Ogness Cc: Greg Kroah-Hartman , Jiri Slaby , Andy Shevchenko , Petr Mladek , Thierry Reding , linux-kernel@vger.kernel.org, =?UTF-8?Q?Ilpo_J=C3=A4rvinen?= , Andy Shevchenko , Crescent Hsieh , Hugo Villeneuve , linux-serial@vger.kernel.org, "linux-tegra@vger.kernel.org" References: <20260828155811.270462-1-john.ogness@linutronix.de> <20260828155811.270462-2-john.ogness@linutronix.de> <20260828160652.TQBsi8oO@linutronix.de> Content-Language: en-US From: Jon Hunter In-Reply-To: <20260828160652.TQBsi8oO@linutronix.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: FR0P281CA0173.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:b4::20) To SJ1PR12MB6051.namprd12.prod.outlook.com (2603:10b6:a03:48a::18) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ1PR12MB6051:EE_|IA1PR12MB8309:EE_ X-MS-Office365-Filtering-Correlation-Id: fe68df80-ac26-4597-e671-08df0526c472 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|10070799003|1800799024|23010399003|376014|7416014|10086099003|22082099003|18002099003|56012099006|3023799007|4143699003|5023799004|11063799006|10067099003; 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:SJ1PR12MB6051.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(10070799003)(1800799024)(23010399003)(376014)(7416014)(10086099003)(22082099003)(18002099003)(56012099006)(3023799007)(4143699003)(5023799004)(11063799006)(10067099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 2 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?citqdjNTTGpXQ0l2TUdzMHh4UlNBTkw2TEtYU0I0QXBHZk9hL1pKZE12RFBP?= =?utf-8?B?NVJFdHlLUVV0TFh6SUFuRHY4VTBHVU1FblB3TWFPNUhYRkdMSHdPRXdBR0Vv?= =?utf-8?B?eWlqcWZEVlVqcWNKMVEzNkRXUXZBUHY5TVJNRkc3Q0IxeTdBRFBQeGloUWxH?= =?utf-8?B?ZGxlK21jRWlRVU1XZlF0WHpUYXFTUUJ4ZWJuZ1lHMVcraURHMUluWW56dzJv?= =?utf-8?B?NWVzNExjZW01S1FZMTFHS1RyWEQwL3BERUovaG9LSThpMTRwdERKejhDdk1Z?= =?utf-8?B?SEloMFRNN2RUUEY3R1VkVjl3Vm9xSkwwR2d6bzY5WmlsUG5iYzdlWHFQZTNa?= =?utf-8?B?M3FvbWVUNzBqc3pYMVY5YmRHdVVCUlZWa0hzNFZRRWl2WnphSEl1cGpPTytq?= =?utf-8?B?NlE4TDd0dVhxa2VZa1Jtb09zeElINUxDM0hQNm1CUDdxUTEyeTQxQVhYVnZC?= =?utf-8?B?c0FMZEx3aEtzT1FSOEV5NG82QXpMR3BUalYvaVM3L014NEhnSElzdmZVRENt?= =?utf-8?B?ekowdkxObnlBR1ZTYmxGVkNrZzJnaUpNUVVTOWpXOHJNVlptdzZ3TU5MZWNH?= =?utf-8?B?bHVDeUx0dHN5bmN2WXE0SHRnMUd3bGxLcHR5dy83Nms0UUZXMURLNktrZmUy?= =?utf-8?B?VHFzZExwQU5SVkRQZ2dpdDJrSGgzbGNEZzN4MHRQMjZYKzQ4VmhZdXRaODha?= =?utf-8?B?czJHMGVUamJOOXhCRDNreG5ENHFPUXJBUjNnL0VsTUFKdGVjRW9pU2JlcmZI?= =?utf-8?B?TmpCaExZOUkvVEdrVUNVQVhZOXhMNmQ1bTRiNFlIeXZmVjFMU3I1dXFWNEVo?= =?utf-8?B?WC9Rcnd3b3VlSzNKckpBYTFKM3dWdnFlallpNUdTK284OHhNRU5BaW1VT2k3?= =?utf-8?B?Y1kwa3h2cXFuR1ZzVXl5TnQ2ZGlQRm1naGJkV3JKS0pDc2IzYkZIMDdyRG54?= =?utf-8?B?SFQwb0hQS3BmKzFMODVUNUZULzVaS1dOd3V5SEJCcDlwczJNNk9GZWtQVUFv?= =?utf-8?B?RWNFMHhEYmVMc0tmOGpTZDdqRWErMjVHeEVycUtxVjRIMUppNGRaN2RWaVFT?= =?utf-8?B?YmhzWUQyVXliVk0zQ21RSzN3d2ROczBrSzhZdnVYN1dYc1J1c000ZytuRGFo?= =?utf-8?B?NUg0MHRQMFhkS1BHdUQ5dXFxdmIzU2tKZmlOQVA2U0N3am5jTDBxaXY0bUV3?= =?utf-8?B?NDlqbXlhbG5FNXBvYzkvYVN3TlpUTWxUWkRwcGpjTWRIL29jNGZleVJLT3hn?= =?utf-8?B?UnNKOGZoeDFlbDUvSTdJbVNuTFI2b1EwVGI4bkJhcGYyZEw0U0NDMjNIMmkz?= =?utf-8?B?TVY0UjdJUXdUcndQTm9WVkdSMy9LOG1jSnlTZ01rQzRTc1RBcTNyNldwUHY3?= =?utf-8?B?cmowRGJnY2thOExhajlYUVJnc0ZsM29teUVlVTVlR3NjdWxubTQrMmFFV0ls?= =?utf-8?B?ZUtBbitSY3NlR3FCYVlPVDFnQ0duVVRTajVWOTdET0QwOWh5U1VZdWdvL2xJ?= =?utf-8?B?M3ZzNi8yVFgvRHdESXB2dmx4VzdYcEJqOHAzSTlCeGw4SXl5V1JTRnlRdnlM?= =?utf-8?B?WVJ4aUZFUlBIWDJLMHkxUXZCdEp4MUt0SlVoWXJqUkhzV2dUckNIWE5iakM3?= =?utf-8?B?L2RCMXYrRjZFVGE2NXVoamhuTHdudk1xVkhYMnJQYXQyQWo0akZ6VVA2QU5u?= =?utf-8?B?NXVNZmJscWxZbDM3aGRGYnlMRlN6RzlQNmZlUytHU0NyUldLU0g3cVc4QVQv?= =?utf-8?B?SVF6ZkFxQVlSMUJRZ2RJdjlaZ2M5ZFNYcVFic3NmelpSSXN6WDVqZ21kMWVQ?= =?utf-8?B?MldzQmZlbDNOQ0VSK1hyT0oyZ0FZRmIwL1NzajNTRCs5S2VDZkJyaWhpMVdH?= =?utf-8?B?Y0xIRzIxVzU5MmxMRjR1UWYzYzIzUmU4eSsyQ0E0QzdZcy9jZjFyMGxPeUJZ?= =?utf-8?B?SXNWakFCczhrUVdTNWowZ3p6MU9Vd1JFVWJWM3ZZZVZ5aHNtRFY4RmEzZ2M3?= =?utf-8?B?RG95OW1XQjJjTndjZk55dGRPMWtlTVhzZ25hVlFQSGtabHg1OUZtKzlNd0pP?= =?utf-8?B?MmdqUmZaaVkrRjVyZHZVYXl1U0hUMndpNTJ2b3BrMGVhdVVURmQ2NDA3QVZ0?= =?utf-8?B?b3Q1ekp1Z0l0RmVhb09WNGRhbFJvTlRmeStScllQTWtSYmx3ZERzSmcyMXAx?= =?utf-8?B?cDcvUjl0NFVreWNRb1JZbnAxKzdYYUhWUEpKMExVWmVkVCtRSXk1d29ZU1h3?= =?utf-8?B?ZzRRNC9tZ3ZydEJJVXJ6Qis4UGFxU2xrajVaN3RKRzZueHE5UDB1bDUwQWRt?= =?utf-8?B?T0VCOVJtZnVkS0xNR3hDclNDQ1QrN25SaTdYZmJjUlZnSmNWN3d3SjRod1FF?= =?utf-8?Q?S+gbJ5ezjzvfVOajQj5MJqeQumCEz97yINifaZ4QqszsP?= X-MS-Exchange-AntiSpam-MessageData-1: sZbTuX6by5zl6Q== X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: fe68df80-ac26-4597-e671-08df0526c472 X-MS-Exchange-CrossTenant-AuthSource: SJ1PR12MB6051.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Aug 2026 17:06:57.5491 (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: MnRewoFEY8oTzYbIAjvf5b/1ZgpiiQ0P8xgc8/0nBL2/9IQ0+WENjeUZ4HWj1Od7ZVdOV4u28PEDX5q8/R0jRg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB8309 On 28/08/2026 17:06, Sebastian Andrzej Siewior wrote: > On 2026-08-28 18:04:08 [+0206], John Ogness wrote: >> For some platforms it is a problem to queue irq_work when entering >> cpuidle states. Since irq_work is used for deferred MSR handling, >> any atomic console printing when entering cpuidle states can lead >> to the affected hardware hanging. Tegra20 and Tegra30 are examples >> of such platforms. Avoiding raising the irq_work IRQ has shown to >> circumvent the problem. > > I would argue that this is done for the benefit of less interrupts since > there no need to handle console_msr_work immediately. With the side > effect that it might fix a bug that was not yet reported on Tegra[23]0. > > Ideally the Tegra folks should figure out what exactly is broken instead > of adding duct tape everywhere else. Yes that would be ideal. Unfortunately these are old devices now and very much in maintenance mode so getting to the bottom of this now is unlikely. You may say then why don't we completely deprecate these, but then you could argue the other way and say they have been working fine up until now. Jon -- nvpublic