From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2F3ADED7B93 for ; Tue, 14 Apr 2026 09:53:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version:In-Reply-To: Content-Transfer-Encoding:Content-Type:References:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=WOyWRcMel/n+SMy1G6Z0U/5T5FcsrWLYRf3gWV6LgIM=; b=JoAPAQy9icQMu8xAKLJSrMigux 5iK83zK+0SfE/FO1MLfNEyHP1HfUF4JsZCqFHNwILh5hhd55ipCXTYVfPI+zv9EuDsBnlVcw/lmP/ N8LHDNneBemItzcrek8z9l/hfQTzzcNADdalECrHj/9Fa9e7g0/nPoJ3FoTs0maiklleSV5JWfXqi g9R3TFOYhKTe0YZ3O5FvZHeRqDw85Qx7ANQFMLtRskLsQiHfPjuv61R7H5xzIFtm8hhjZO6Dyl3LQ RDJLS+J7nh8Jq+Q6xNiIuC20E2FbhEXCc0U4DXuQXlCDqShn7vkiQ0RFlgcq71NkJlAYsg5fRypvB 7oKWnKtA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wCaSg-0000000H5Vk-0lWS; Tue, 14 Apr 2026 09:53:38 +0000 Received: from mail-francecentralazlp170130007.outbound.protection.outlook.com ([2a01:111:f403:c20a::7] helo=PA4PR04CU001.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wCaSd-0000000H5V9-08Rq for linux-arm-kernel@lists.infradead.org; Tue, 14 Apr 2026 09:53:36 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=L2+n02OVcSKlN1IxpXtIw4OtQZiD+a8hddvXuwHl4buI+ZP3BAdBp704S/57ftjrhOaxycbR6R/YMaP5jD3pTT09yJ1isIhGX1EpY1kgRFsSF7xIDd0UbkoOzgjg4RTDVJFBdlEw9Ni4IYyMLBfcW/ykmX8U+7fwUi4Xc9jG8qouAChTklmqITdPYx7pPuF6wZGrQzDmcH4EGSFZ8NwuPikLDaATV57QTTE6jveeFQjTuZvDP6GOGFo/cdIQrRuYDfIZ2qdtBZMtKx2eEc6ho8XIvlDMNdLdItZzhwryxe8jkY1tpDNrWBKk3PN1ZzI12kdyZFcjpgf2tAkTbmTDbw== 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=WOyWRcMel/n+SMy1G6Z0U/5T5FcsrWLYRf3gWV6LgIM=; b=ezsz0VoVMu+6ei6MFxDWD90dCrT4tOsShQtreW7QujDjP/rYHLVcHJs9n7W0pyIULDo7Q93Y223qCtCd0fgD1xWmQGawZUQwYxzXx40VfM+p8Z+hFlaQrHkUlu3PPbP1wtqjcCW7Zs7+BahYaMfzYoZw3VPRRTWDDFWW+GzbWiLWCtb0Q/RbhUjKwRLgZvkmMgZigXEb6XZFF9k62OxmuBnb0mIbxQrvl8EgZJL9sj/du8QSyQel5wOnHltSa0QdExGGlLIvE3lCkorIgdIReDtzoJ7v3/zIqEG9oGqtfiZ5JFapd4XidiSbMxGj8dnBOp4z+LxanHzNhn/YUiEfOw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nxp.com; dmarc=pass action=none header.from=nxp.com; dkim=pass header.d=nxp.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nxp.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=WOyWRcMel/n+SMy1G6Z0U/5T5FcsrWLYRf3gWV6LgIM=; b=m4inp6OFVJ995N9N1sPY6u5sMiuu6LPLw4EUUaz1i66pSzXwHWTz2MRLkn8nJdCCf14hBp68gic7qSu2eFSdNN+fgMQkcQoyk6uY7Pk/CtIgPYWgtUR19xSSjIpv1MNBXbqs6pMdhuGjF22aFTJCXrvncMwqYwPoBS+ESa380ft7eUwDqfd44et7+Rx6IOB6zPOTql7RAQoZRcYw1DbT5pmwnPDzyzaOxrsAx9t00MFvSthq7uM2kZjoK1We1hxRZZmijythfqMB/+qxCX6rq9jm9Oh/sCOoVOVLykoQC0EHPNaunj9GmCOSk+Fjj1VJIWBZbKRt+a3QImDFyGgLRQ== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nxp.com; Received: from PA4PR04MB7821.eurprd04.prod.outlook.com (2603:10a6:102:c5::5) by PAXPR04MB8782.eurprd04.prod.outlook.com (2603:10a6:102:20d::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9769.48; Tue, 14 Apr 2026 09:53:28 +0000 Received: from PA4PR04MB7821.eurprd04.prod.outlook.com ([fe80::67dc:4bd2:8552:9b50]) by PA4PR04MB7821.eurprd04.prod.outlook.com ([fe80::67dc:4bd2:8552:9b50%5]) with mapi id 15.20.9769.046; Tue, 14 Apr 2026 09:53:28 +0000 Date: Tue, 14 Apr 2026 17:55:32 +0800 From: Robby Cai To: Philipp Zabel Cc: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, Frank.Li@nxp.com, s.hauer@pengutronix.de, festevam@gmail.com, devicetree@vger.kernel.org, kernel@pengutronix.de, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, aisheng.dong@nxp.com Subject: Re: [PATCH 1/2] dt-bindings: reset: imx8mq: Add _N suffix to IMX8MQ_RESET_MIPI_CSI*_RESET Message-ID: <20260414095532.GA2624044@shlinux88> References: <20260331101331.1405588-1-robby.cai@nxp.com> <20260331101331.1405588-2-robby.cai@nxp.com> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: SG2PR02CA0073.apcprd02.prod.outlook.com (2603:1096:4:90::13) To PA4PR04MB7821.eurprd04.prod.outlook.com (2603:10a6:102:c5::5) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PA4PR04MB7821:EE_|PAXPR04MB8782:EE_ X-MS-Office365-Filtering-Correlation-Id: cbdb00c4-5c3c-422f-f5c6-08de9a0bad69 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|52116014|1800799024|19092799006|7416014|376014|366016|38350700014|18002099003|22082099003|56012099003; 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:PA4PR04MB7821.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(52116014)(1800799024)(19092799006)(7416014)(376014)(366016)(38350700014)(18002099003)(22082099003)(56012099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?dW9rTEU2dG8vc0REKzliNHFVSGVKWk81SXNrSTlnWEpraCsxRmI4cFd6Rm5N?= =?utf-8?B?TFBnU0ZWZmhtbCtxRk54TEFaZGQ5dmpndVAzUmlxTC9yc280WHdDcjYwcVpO?= =?utf-8?B?cVh5T1F6V1dEN3FBbjVyZEp0R0dXUXhNRy91WUMwVmZqSU9aMm93clVIK0hK?= =?utf-8?B?SkFWYXI3MUZFQ1E2ZGR2TXk1bTI4UlFZSmFYRmdNd1FBblBwazBGUlpFNnlH?= =?utf-8?B?LzMxOUFmUUFlWnZDaFpHaXF4UzZaQVNkdlZPZVk2dThMMm82bzI5Y3VaL092?= =?utf-8?B?aUhKbzhXSHhETG1EU2RjcU96ZHVOZGNSMDhHWEY4YUtyYmdnb3FPZnNqRU03?= =?utf-8?B?ODF2akgvQWdkVElKUi83TGJqbk1wdCsweExjZWk4a2NCWENiWjBJZ0RGWUZh?= =?utf-8?B?bjNRQzBpYlNLL3N5dTliamlUYVFhRVRsN0o4Tlhmb1p1dVVld3k2OE11R3Vy?= =?utf-8?B?cHN0REdiMmhGSnFhY0tmNFFyVUNMbTN4ZE9rRWNkWjRES0hDdWpNZWFEdFZR?= =?utf-8?B?Z1Z3VDBtcktnNU83YitBYXhQaTU3aitGbU5yT0hsTjA2TGZRNW5aWFJORE5Q?= =?utf-8?B?WERZcno5YUhEWWluL1BIWGdXTktWWmRBbTBQNmFRVzZNMWFkbytZb3h6Yjk1?= =?utf-8?B?MFF2K2tIcnlWN2I4Qi8yd29XMndQVTdrYVNpaEdOVmt4aHpsQUZlN0k0b3FY?= =?utf-8?B?a3ZvY0l3ZW1adFZicllLbDlLUlRRWC9nNGZCZERiVDMwSGZpeWJ3RzZGaktT?= =?utf-8?B?SmNNTjBOZ25lc0dtRk55MkdhS2JOY09Rbmo4eTZJdHlReHkzYzU0Y3E5T3VC?= =?utf-8?B?SHJROTBDYkMyVVMvQUxsQnYvYUYyNjRHdlRPOGVKZm5QL2xPTU1lU245UEpS?= =?utf-8?B?ZEZvTlNOVTVzT0FWaHd1OUp4N3BrdVg3MFhzdEFBSEJSWlJRbitNbXhxTlJw?= =?utf-8?B?bGNLOUVibktLU3l6ditkTWVNeEpCQ01DUlFLUTJkbDB1QU9UcmxsUnk2OFkz?= =?utf-8?B?UmJjOGlDbWUyNmlFK1JNZVhkZzU1cDdlMzh4RnFGK2srb01pTzVTVkdFRnVt?= =?utf-8?B?aHN2R0tUN1JFOTZtdkFCZFcvMWhzdDNXYlphbko2c0JvREVyVXNUWHJpem1V?= =?utf-8?B?ek5oTEt3UTUvWDB2UFRZNmdVM1NhdHNsbm5zSnpnQ1ZHTGF0YW8xK2lURVNx?= =?utf-8?B?c2JhZ2x0VzN6RTBRSnI5L3ZXdFRUMmNSWEZRSFRaR2l3ZlBTZG5WMnNhRnpq?= =?utf-8?B?UXdDM2xLdDlZTnA1YVZkTFBhbUhVUXFDT2d1OXRPQnlKVVdnT2pEbTNPS0VG?= =?utf-8?B?d0pHMHhDWEhZeHlLVElMQ25aN0xCNG54MnRBWkoweUZzaGVlK0RtSjJSTmlD?= =?utf-8?B?YlVJZkN2NE5yL3lvd2dTR0tZUHY0MENnZmNJZzFVNC8rVTRGV053VVgraUp5?= =?utf-8?B?d00zS2xoOHdOdEVkOFlIVElMZENUWmFWZVVDd1BXbElRM2FoQy9iLzMyeWFE?= =?utf-8?B?QUdzeldDZWpreXdWQjdEUFpRdEpteVgzRUorKyt5WVo3RkN3ZDZ3NzBSV084?= =?utf-8?B?VHRNL1Byc1BFTmJoVGtLNUw2TWhmSUtGdllVakJveFFjVURDMHRsSzZsb1pZ?= =?utf-8?B?SkwrdDJQN3dhUlI2SlVJV3dMRTZoNEFNelpnQXY3bWhIalJvaW9uVmFRdGUz?= =?utf-8?B?RXdyV2dZV0ZMZmwrd2VFMmUrQ2dKT0hmSHg5QnYzSVladGRQcnRwZGFQRHB2?= =?utf-8?B?eTBVM2dDbklhQXZhdy9zcDhya2dQRGhwQzl4djBaNE00Tnd0dlhldWNZRFY3?= =?utf-8?B?VkpiRUtNVDFzVW90MytHUWVJanRwTTlaK0hhdXdzQ1VGRVRrRUhOVmlRWGtU?= =?utf-8?B?bkRpT2ZFUng0YzhhK1N4OFFjRFBvcThXT3FuZ3B3emJqd2gwcm5QODB1aUhx?= =?utf-8?B?Yk9zMmd5Z3FsaUwwRSszVEdVbGFyUzg0UEdwV3Z0VVpQNHU3NGlvdHVGNm1F?= =?utf-8?B?dzFWSFl1NEhndVBnUGhFR2x5UXJyMWtQNENHWVN1RFBuUWphUGtoN2p0RWd2?= =?utf-8?B?TFdLeGZKckl4cnQwaUg0ZzYwck1FM0FtdFdLeU1oQSthMG0yZnJVSUMxcUZR?= =?utf-8?B?c0JncHk4eWZyQzBjd3VBNWZXOTMxS3YxcDdaSk44OEV2MnAzQS9KMmNyWGxl?= =?utf-8?B?dVVydWpKTnRjTzMyVCt0bSsxY1NuMlJVd25MTitaRUNsODJta0JuZ1RRY2pa?= =?utf-8?B?d0szdUYrRGEwTC8yOWdoYkhFNG1YWmZtS25vakQxdGhIRG4reW1IdEtOdzl3?= =?utf-8?B?TVZKci8zWGN2ckNkMzNQVlViNnJicndOSTNyZ0ZJQjRySVY1bko0UT09?= X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: cbdb00c4-5c3c-422f-f5c6-08de9a0bad69 X-MS-Exchange-CrossTenant-AuthSource: PA4PR04MB7821.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 Apr 2026 09:53:28.1444 (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: /c0/OIc2LnlaBnh5eAZsa6BndWAQPIk5GDCZZgC1Z5vauPmvDWqxZXLO7iDYBQfsrh/a39Z/dZ3LlaiDgKN/Xw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PAXPR04MB8782 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260414_025335_086102_27605EC7 X-CRM114-Status: GOOD ( 22.64 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Mar 31, 2026 at 02:45:07PM +0200, Philipp Zabel wrote: > On Di, 2026-03-31 at 18:13 +0800, Robby Cai wrote: > > The assert logic of the MIPI CSI reset signals is active-low on i.MX8MQ, > > but the existing names do not indicate this explicitly. To improve > > consistency and clarity, append the _N suffix to all > > IMX8MQ_RESET_MIPI_CSI*_RESET definitions. The deprecated > > IMX8MQ_RESET_MIPI_CSI*_RESET versions remain temporarily for DT ABI > > compatibility and will be removed at an appropriate time in the future. > > The register description in the latest reference manual I can download, > IMX8MDQLQRM Rev. 3.1 (06/2021), still call these bits > MIPI_CSI1_CORE_RESET and so on (without _N). There is no mention of > polarity in the bitfield description. Is a documentation update > planned? Yes. A documentation update is already planned to clarify the reset polarity (active-low) and naming. The current RM description is incomplete and will be corrected in a future revision. > > Right now I'd say this improves clarity, but reduces consistency with > existing documentation. > > Are these bits self-clearing, or can the reset be asserted by writing > 0? As it stands, the CSI driver using these resets, imx8mq-mipi-csi2.c, > only calls reset_control_assert() in imx8mq_mipi_csi_sw_reset(): > > /* > * these are most likely self-clearing reset bits. to make it > * more clear, the reset-imx7 driver should implement the > * .reset() operation. > */ > ret = reset_control_assert(state->rst); > > This will probably have to be turned into a deassert together with the > reset driver change. No, these reset bits are not self-clearing. According to the design team, the MIPI CSI reset logic on i.MX8MQ is identical to MIPI DSI: the reset is active-low and must be explicitly deasserted. Writing ��0�� asserts reset and it will remain asserted until cleared by software. The current assumption in the CSI driver that these bits are self-clearing is therefore incorrect. This was exposed by the landing patch [1]. To fix this properly, the reset-imx7 driver needs to reflect the correct polarity, and the CSI driver should use deassert instead of only calling reset_control_assert(). The RM will also be updated to clarify this behavior. [1] https://git.linuxtv.org/media.git/commit/?id=6d79bb8fd2aa25afccbd6aeec2821722fa0b5db5 Regards, Robby