From patchwork Fri Dec 8 03:31:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Quan Nguyen X-Patchwork-Id: 175553 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:bcd1:0:b0:403:3b70:6f57 with SMTP id r17csp5220560vqy; Thu, 7 Dec 2023 19:32:31 -0800 (PST) X-Google-Smtp-Source: AGHT+IFWz9CZ5lkBtUIEK+//g1TMVCRdKjzONufL07LAx3BbG8oabIg+YWSato4sxIdE+hJ97yeN X-Received: by 2002:a05:6a00:84f:b0:6cb:6407:defb with SMTP id q15-20020a056a00084f00b006cb6407defbmr3996073pfk.26.1702006350705; Thu, 07 Dec 2023 19:32:30 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1702006350; cv=pass; d=google.com; s=arc-20160816; b=InepM4iO2a4PfiWQL6gxoHR35sZ2bbE6R1+QjDtNSke1BrTMJRHX7WIlnpKUqwqu+T dppvNcEOjrdhYutK2N4NPlJ6BIOJUvGWg9tsMiwc9rnJudIAA+utNMnXVhm0Xgc7hCsd 4yHWq91agMKewGwP4DWQL061rzhZXtQhu3kxzkrSrOe2m5b8yNt1CR2nImzQ2gl5hXhK SnVQ6GZp9D1Va11cdVvRjhIjstJMVnzoyMbzkR8fqLgV7jsTkL5KAnxcHHPFduMXb+v4 pM+tdmOrw8t5y3R8ZURdIBaKHh7Emdtgz6HsYiTaPgu6tN6Iq+sTsAjxMc7qytZCrfSJ KtcA== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:content-transfer-encoding :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=vEQEln+Pxrd+g7XX0Erli+WSVR/HUZwZxj47st23ww4=; fh=WFcqSubssMIwC0Dm7Plh6RRvLP+WIFWeZgWd743wkLo=; b=STm03RMwoe/gXTonR9HDnoIWa/nSG5ivjb55zqNnQzyiPwKuLxxSo6IIZ3Quu1uRPd w3iy3VKVJCXsgCV/JO/v4TcCIG5DqlSaR7m1+TpINGa6ahnSIqKslOLMaty7DAhRbqXo xb1V71UvU97WzYC10RhinGntkHDjtIxbGV7cAnAucTU2rk1RxCsLiVQaC3iiy2Gsmxqp jw54QTkFTaQPDXM1PgIhuwJftsWVmUN+wkLI7oF5jaCu/KPSN5kWewZnIspA4s/8n4K/ nPmjFjp4JReAvF+KzcqwVkFv98wXhOqpPfi3h6wBel65ntBuZCXQigxL5HeJF8Owr14m N4wA== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@os.amperecomputing.com header.s=selector2 header.b="HtVU/xeQ"; arc=pass (i=1 spf=pass spfdomain=os.amperecomputing.com dkim=pass dkdomain=os.amperecomputing.com dmarc=pass fromdomain=os.amperecomputing.com); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=amperecomputing.com Received: from morse.vger.email (morse.vger.email. [2620:137:e000::3:1]) by mx.google.com with ESMTPS id fi29-20020a056a00399d00b006bf531dd685si807676pfb.64.2023.12.07.19.32.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Dec 2023 19:32:30 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) client-ip=2620:137:e000::3:1; Authentication-Results: mx.google.com; dkim=pass header.i=@os.amperecomputing.com header.s=selector2 header.b="HtVU/xeQ"; arc=pass (i=1 spf=pass spfdomain=os.amperecomputing.com dkim=pass dkdomain=os.amperecomputing.com dmarc=pass fromdomain=os.amperecomputing.com); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:1 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=amperecomputing.com Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by morse.vger.email (Postfix) with ESMTP id 65316836CE4A; Thu, 7 Dec 2023 19:32:27 -0800 (PST) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.11 at morse.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232752AbjLHDcO (ORCPT + 99 others); Thu, 7 Dec 2023 22:32:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230225AbjLHDcK (ORCPT ); Thu, 7 Dec 2023 22:32:10 -0500 Received: from NAM04-BN8-obe.outbound.protection.outlook.com (mail-bn8nam04on2134.outbound.protection.outlook.com [40.107.100.134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7234A173B; Thu, 7 Dec 2023 19:32:13 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=mz+abDYuDut4REYi/I0ZHaabkE4LOY48DilKsT/NGM+ZroVCszEwQj7Yvyuj4ZB4RButAkV+x31Zq194ax7A1pTAWMiMLLIYJK4mweW3DGkMWm1K1262ReVGkvZ8yixpi2Y0N+N+YjGcPLhsz8l2BuWWnZBkhm9iqGKfuXtz+kCMTI6pNBn69Oc1o36ulfLE8r6sDnlvSnLHe0uG+1MbsQO5CWBhF4TNNhMwieea5YQpy5K2CkJ1xhnuM427tY48YIbgz+sup71h/QqjqYUsoEb3rTZYUFi847rCRZzdFl8dwxG22ErA/IrzjP20QeutvS3f4pcQj6vDER0m3M/C3A== 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=vEQEln+Pxrd+g7XX0Erli+WSVR/HUZwZxj47st23ww4=; b=C6hKiO4C4/GbtwPNu3BHdaSGxlDxMpGpc3foMwQURPOgECAB+UXUzb9qfeTUHwtlG/ElAPOY5G4WU8UT7o5YX70TAXLZXQ3p+jruc0W6IGJacWXX2XFHpxG9YbpAXF3oUI6WAerOZDDO8j1JLKjh6ApiyRLbj6EQ4ihxypzrZ1kxxfitj1ewtEfAcB3tAKf5tLUrMV3kTk+wPXoPPALmfNlLujsF1crMi18rt9UzyGVDP7yq/GNA2AtegDESbJ9W7cwL96tWFdV71dsBalvK9SsnGnIkeiHKdNYgA6V2femouzC2WzcnqJfgnOnTG8Ss2XzLNzYpru/X8XO0qpbzmw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=os.amperecomputing.com; dmarc=pass action=none header.from=os.amperecomputing.com; dkim=pass header.d=os.amperecomputing.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=os.amperecomputing.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=vEQEln+Pxrd+g7XX0Erli+WSVR/HUZwZxj47st23ww4=; b=HtVU/xeQ1YtTH/424Dr6exUPOAVgEx4hZJp5NYwgNjbPr2FMdtLxuT0iv5dKL5/XAF7mY+I+ttLBoJH/btYs6Mz66f3BYcrnLz6KHmL4Q//IM6bAYw5U+nv9pJLEZw74UJcIDzbSnG7WmKM4ZqD+aQSzX3Zz6VbX1j9dA4BhZr0= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=os.amperecomputing.com; Received: from SN4PR01MB7455.prod.exchangelabs.com (2603:10b6:806:202::11) by DS7PR01MB7784.prod.exchangelabs.com (2603:10b6:8:7f::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7068.27; Fri, 8 Dec 2023 03:32:09 +0000 Received: from SN4PR01MB7455.prod.exchangelabs.com ([fe80::5682:1d84:171a:1d68]) by SN4PR01MB7455.prod.exchangelabs.com ([fe80::5682:1d84:171a:1d68%3]) with mapi id 15.20.7068.028; Fri, 8 Dec 2023 03:32:09 +0000 From: Quan Nguyen To: Brendan Higgins , Benjamin Herrenschmidt , Joel Stanley , Andi Shyti , Andrew Jeffery , Wolfram Sang , Jae Hyun Yoo , Guenter Roeck , linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org Cc: Cosmo Chou , Open Source Submission , Phong Vo , "Thang Q . Nguyen" , Quan Nguyen Subject: [PATCH v3 1/2] i2c: aspeed: Handle the coalesced stop conditions with the start conditions. Date: Fri, 8 Dec 2023 10:31:41 +0700 Message-Id: <20231208033142.1673232-2-quan@os.amperecomputing.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20231208033142.1673232-1-quan@os.amperecomputing.com> References: <20231208033142.1673232-1-quan@os.amperecomputing.com> X-ClientProxiedBy: SGAP274CA0014.SGPP274.PROD.OUTLOOK.COM (2603:1096:4:b6::26) To SN4PR01MB7455.prod.exchangelabs.com (2603:10b6:806:202::11) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SN4PR01MB7455:EE_|DS7PR01MB7784:EE_ X-MS-Office365-Filtering-Correlation-Id: 89633b98-bcc3-45f3-f07b-08dbf79e4240 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:SN4PR01MB7455.prod.exchangelabs.com;PTR:;CAT:NONE;SFS:(13230031)(346002)(376002)(366004)(39850400004)(136003)(396003)(230922051799003)(1800799012)(64100799003)(451199024)(186009)(66899024)(38100700002)(41300700001)(7416002)(5660300002)(2906002)(8676002)(38350700005)(316002)(4326008)(921008)(1076003)(110136005)(478600001)(6512007)(6666004)(6506007)(52116002)(2616005)(66476007)(86362001)(66556008)(54906003)(26005)(66946007)(107886003)(8936002)(83380400001)(966005)(6486002);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 X-OriginatorOrg: os.amperecomputing.com X-MS-Exchange-CrossTenant-Network-Message-Id: 89633b98-bcc3-45f3-f07b-08dbf79e4240 X-MS-Exchange-CrossTenant-AuthSource: SN4PR01MB7455.prod.exchangelabs.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Dec 2023 03:32:09.5231 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3bc2b170-fd94-476d-b0ce-4229bdc904a7 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Z6G5GZfauDSwV1pkNdn6C7ZyKp0fstj/PFCss0K9VIKwXpQ73DIk/NDj5D9nLFM5/Qlv9Xh1nPUZvNNumCLD0f7Iu0r+SMdo+Fw8AkxcvIs= X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR01MB7784 X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on morse.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (morse.vger.email [0.0.0.0]); Thu, 07 Dec 2023 19:32:27 -0800 (PST) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1784683011174475388 X-GMAIL-MSGID: 1784683011174475388 Some masters may drive the transfers with low enough latency between the nak/stop phase of the current command and the start/address phase of the following command that the interrupts are coalesced by the time we process them. Handle the stop conditions before processing SLAVE_MATCH to fix the complaints that sometimes occur below. "aspeed-i2c-bus 1e78a040.i2c-bus: irq handled != irq. Expected 0x00000086, but was 0x00000084" Fixes: f9eb91350bb2 ("i2c: aspeed: added slave support for Aspeed I2C driver") Signed-off-by: Quan Nguyen Reviewed-by: Andrew Jeffery Reviewed-by: Andi Shyti --- v3: + Change to handle the coalesced stop condition with the start conditions [Andrew] + Revised commit message [Quan] v2: + Split to separate series [Joel] + Added the Fixes line [Joel] + Revised commit message [Quan] v1: + First introduced in https://lore.kernel.org/all/20210519074934.20712-1-quan@os.amperecomputing.com/ --- drivers/i2c/busses/i2c-aspeed.c | 47 ++++++++++++++++++++++----------- 1 file changed, 31 insertions(+), 16 deletions(-) diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index 28e2a5fc4528..1c2a4f4c4e1b 100644 --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -249,18 +249,45 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) if (!slave) return 0; - command = readl(bus->base + ASPEED_I2C_CMD_REG); + /* + * Handle stop conditions early, prior to SLAVE_MATCH. Some masters may drive + * transfers with low enough latency between the nak/stop phase of the current + * command and the start/address phase of the following command that the + * interrupts are coalesced by the time we process them. + */ + if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) { + irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP; + bus->slave_state = ASPEED_I2C_SLAVE_STOP; + } - /* Slave was requested, restart state machine. */ + if (irq_status & ASPEED_I2CD_INTR_TX_NAK && + bus->slave_state == ASPEED_I2C_SLAVE_READ_PROCESSED) { + irq_handled |= ASPEED_I2CD_INTR_TX_NAK; + bus->slave_state = ASPEED_I2C_SLAVE_STOP; + } + + /* Propagate any stop conditions to the slave implementation. */ + if (bus->slave_state == ASPEED_I2C_SLAVE_STOP) { + i2c_slave_event(slave, I2C_SLAVE_STOP, &value); + bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE; + } + /* + * Now that we've dealt with any potentially coalesced stop conditions, + * address any start conditions. + */ if (irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH) { irq_handled |= ASPEED_I2CD_INTR_SLAVE_MATCH; bus->slave_state = ASPEED_I2C_SLAVE_START; } - /* Slave is not currently active, irq was for someone else. */ + /* + * If the slave has been stopped and not started then slave interrupt + * handling is complete. + */ if (bus->slave_state == ASPEED_I2C_SLAVE_INACTIVE) return irq_handled; + command = readl(bus->base + ASPEED_I2C_CMD_REG); dev_dbg(bus->dev, "slave irq status 0x%08x, cmd 0x%08x\n", irq_status, command); @@ -279,17 +306,6 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) irq_handled |= ASPEED_I2CD_INTR_RX_DONE; } - /* Slave was asked to stop. */ - if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) { - irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP; - bus->slave_state = ASPEED_I2C_SLAVE_STOP; - } - if (irq_status & ASPEED_I2CD_INTR_TX_NAK && - bus->slave_state == ASPEED_I2C_SLAVE_READ_PROCESSED) { - irq_handled |= ASPEED_I2CD_INTR_TX_NAK; - bus->slave_state = ASPEED_I2C_SLAVE_STOP; - } - switch (bus->slave_state) { case ASPEED_I2C_SLAVE_READ_REQUESTED: if (unlikely(irq_status & ASPEED_I2CD_INTR_TX_ACK)) @@ -324,8 +340,7 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED, &value); break; case ASPEED_I2C_SLAVE_STOP: - i2c_slave_event(slave, I2C_SLAVE_STOP, &value); - bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE; + /* Stop event handling is done early. Unreachable. */ break; case ASPEED_I2C_SLAVE_START: /* Slave was just started. Waiting for the next event. */; From patchwork Fri Dec 8 03:31:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Quan Nguyen X-Patchwork-Id: 175554 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:bcd1:0:b0:403:3b70:6f57 with SMTP id r17csp5220624vqy; Thu, 7 Dec 2023 19:32:41 -0800 (PST) X-Google-Smtp-Source: AGHT+IG3Lw0hJPxrqT5v3eekBWXPPqiXhSnYeeZFyYx6LSxDyBygrW+fnMk23z/Dijv+DU74+1+L X-Received: by 2002:a05:6871:4414:b0:1fb:d89:4879 with SMTP id nd20-20020a056871441400b001fb0d894879mr4021054oab.26.1702006361219; Thu, 07 Dec 2023 19:32:41 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1702006361; cv=pass; d=google.com; s=arc-20160816; b=mSP6EQYGmVaD6WsMltQhmXnlc3No53g1tyK6pl4TNi+//F3FAuhNd9OWjc72/v7TBJ 2S5KqLnSbGu3y8xVMhQPim5/ZKOz1Sj1r+HlQpuDcuHwE+p45b3erWuxVq5UnqPaVMcP iELWNfbxf0CSYzXDbO+8Rx7mV1ZLXrr6DoLQSW3UGgQqumJexmzXCOgaAvtMfXNMFUYn ho+rTUyp8qr9mq8KrhL3kLujs4TMJ2Q/idROE6kXbDMsTRxFivmZyBUEHH+r9PABQ8wP uybBFpDBXewsZ8SAk5mmwejwK7+wdjBWaTBP4Nb5DuArrZfLMxwiAO5sDhrMQVk2PK9p L1Yw== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:content-transfer-encoding :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=YlMP3M3fABHaRpRNGuvf9NO+rSFvhyPtOwBNy1e3lk4=; fh=WFcqSubssMIwC0Dm7Plh6RRvLP+WIFWeZgWd743wkLo=; b=czIZ4s+he9RMJbdoicdROgc+gy9bL/VPh+zycwSxumhSdRKXhiFa2eJvbyLt55obLj TZkn5z6JYlDI8VTX8NlO8ZdEe0/fxW4g5IYcnBr8sR3lQmfgLq231QKoMvVsgwI8kv9i aY5G1PE9OAIGANCYTBUhjo7CG25ZXB8I7WoG3YLnaKsdI43HWLX/Bg0rTr6VW6YEgW/X 0C6sXC0/wjB4J6ONX+ikur3i15IcakK+lQNH/UtLDDgyi61WVqhz8cGVxW3zdqqdEWg9 hOH/5q65V5inzldtHlpM/VaKZ0Wm4Clf/JjNPf7JTAKdlOtpXgWNZ6B12afZ9ZhgsQLz CBDA== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@os.amperecomputing.com header.s=selector2 header.b=g8fz7HTK; arc=pass (i=1 spf=pass spfdomain=os.amperecomputing.com dkim=pass dkdomain=os.amperecomputing.com dmarc=pass fromdomain=os.amperecomputing.com); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.31 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=amperecomputing.com Received: from morse.vger.email (morse.vger.email. [23.128.96.31]) by mx.google.com with ESMTPS id o62-20020a634141000000b00565ead2509asi752297pga.199.2023.12.07.19.32.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Dec 2023 19:32:41 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.31 as permitted sender) client-ip=23.128.96.31; Authentication-Results: mx.google.com; dkim=pass header.i=@os.amperecomputing.com header.s=selector2 header.b=g8fz7HTK; arc=pass (i=1 spf=pass spfdomain=os.amperecomputing.com dkim=pass dkdomain=os.amperecomputing.com dmarc=pass fromdomain=os.amperecomputing.com); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.31 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=amperecomputing.com Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by morse.vger.email (Postfix) with ESMTP id 73E15836CE46; Thu, 7 Dec 2023 19:32:38 -0800 (PST) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.11 at morse.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1573090AbjLHDcQ (ORCPT + 99 others); Thu, 7 Dec 2023 22:32:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1573078AbjLHDcN (ORCPT ); Thu, 7 Dec 2023 22:32:13 -0500 Received: from NAM04-BN8-obe.outbound.protection.outlook.com (mail-bn8nam04on2134.outbound.protection.outlook.com [40.107.100.134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0EA451727; Thu, 7 Dec 2023 19:32:18 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Lbt3JChCNqavGZdEg0/bbTeXhCFjQmg4IygDkZdLCKwI78BzCwaKw523mc9bf3xVodAkWxi2r0+sePZC0VFOObefUezraMEg6WBIYwkWSSf41V7As9ITBW2HLZX9bsoZFzITbtPXk+vx79S01SFjIFQC2hlBJqC0rvDBEfDK91YCyAGSftbRFm/pUOoEWTEJkfyrmhGFsA/Uv8UmT9pcsqG/CAMYb2JQJ7v5Is9auTk6c1fSD3aBcXfx1eSW8gUJPLBZqZgaW72G3GUqV9fbLzRw8QomWv0M1J+nzJDhjvPk/UTz39XkoCg4ceZNUai/2cZzI9XCqiOtK7sqmWq90A== 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=YlMP3M3fABHaRpRNGuvf9NO+rSFvhyPtOwBNy1e3lk4=; b=UrK9W3+7BS0mn3Me70j67aW7uL5bk901c6npHQuUevoy3I3xGjYLaY1YwPmWhseh8zwi2KrjHez5p14gz6MsFTZxA/14TvszrqSJ5mZXb9X+2w/fSOldrgBkLXmkaxi/eRrQhCdFqoPzxK2i6oJMMQ98ExAhHxd/2ejxUu8FKaMLjQe4c8dGMm2BR1nygFn4E0Ery9B5EHgpU/jIOpUdjHbkV7dzTyoMneYA6eNy9Y7M82V8VczZlJOgy1eJhbvhB8a1RncMpFO0i8ba5DIAadN+D9OTljR6xM3gNySUhOXGHtn4Ok0O8IqpBN0AYX+w+OucOa+nOUhQQ4PPykXCLQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=os.amperecomputing.com; dmarc=pass action=none header.from=os.amperecomputing.com; dkim=pass header.d=os.amperecomputing.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=os.amperecomputing.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=YlMP3M3fABHaRpRNGuvf9NO+rSFvhyPtOwBNy1e3lk4=; b=g8fz7HTKarJoVFqPCz6+S6iYs6VwOXHQ1vI0wJ37tDXCdto187vLgthfHpuWfFZo3CnZpy9QpnPHDJbUh1j2+Db9VVs+Agordubk//kq0soZrkIUk9nGWQwpIPmb1ARRj2Vb5+t4IJHH1BAEZG8sVbGHDg0XNQPb9w6QX6Vmtpg= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=os.amperecomputing.com; Received: from SN4PR01MB7455.prod.exchangelabs.com (2603:10b6:806:202::11) by DS7PR01MB7784.prod.exchangelabs.com (2603:10b6:8:7f::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7068.27; Fri, 8 Dec 2023 03:32:15 +0000 Received: from SN4PR01MB7455.prod.exchangelabs.com ([fe80::5682:1d84:171a:1d68]) by SN4PR01MB7455.prod.exchangelabs.com ([fe80::5682:1d84:171a:1d68%3]) with mapi id 15.20.7068.028; Fri, 8 Dec 2023 03:32:15 +0000 From: Quan Nguyen To: Brendan Higgins , Benjamin Herrenschmidt , Joel Stanley , Andi Shyti , Andrew Jeffery , Wolfram Sang , Jae Hyun Yoo , Guenter Roeck , linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org Cc: Cosmo Chou , Open Source Submission , Phong Vo , "Thang Q . Nguyen" , Quan Nguyen Subject: [PATCH v3 2/2] i2c: aspeed: Acknowledge Tx done with and without ACK irq late Date: Fri, 8 Dec 2023 10:31:42 +0700 Message-Id: <20231208033142.1673232-3-quan@os.amperecomputing.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20231208033142.1673232-1-quan@os.amperecomputing.com> References: <20231208033142.1673232-1-quan@os.amperecomputing.com> X-ClientProxiedBy: SGAP274CA0014.SGPP274.PROD.OUTLOOK.COM (2603:1096:4:b6::26) To SN4PR01MB7455.prod.exchangelabs.com (2603:10b6:806:202::11) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SN4PR01MB7455:EE_|DS7PR01MB7784:EE_ X-MS-Office365-Filtering-Correlation-Id: a89b4120-66dc-4f5f-b8e2-08dbf79e45b0 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:SN4PR01MB7455.prod.exchangelabs.com;PTR:;CAT:NONE;SFS:(13230031)(346002)(376002)(366004)(39850400004)(136003)(396003)(230922051799003)(1800799012)(64100799003)(451199024)(186009)(38100700002)(41300700001)(7416002)(5660300002)(2906002)(8676002)(38350700005)(316002)(4326008)(921008)(1076003)(110136005)(478600001)(6512007)(6666004)(6506007)(52116002)(2616005)(66476007)(86362001)(66556008)(54906003)(26005)(66946007)(107886003)(8936002)(83380400001)(966005)(6486002);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: yJP4exEKch3CkzPFSPfMms+t1cRdqzQsozSyuSBYjKGMlyiwOKdr7N9HOE9OBqHIZXrqGyEy6UGsvPE11Sb8O8WkZURJzpNU0HDID6ll7R3n0gFbL+RkjpN6FR58fapIFQu0oMrmxUwG5Hgh+V83x2uILmsNTRofiCPrQoCfs/zuyZY2v/pP6rmLaqFrKj99LLVP95NbmcgXceT6DD34uMheNLGPjNVq6GyhpE/3QnyriZz0zX9OVqBURkmilSPZ1tXb7AzYUncpJzujd4AYcUso27Bj5l9Gc87JGYSGcSa5SdO+7N9hoUCLFjSsOl/nrlb75tUHe7wuqTsdG0+6m30QVQeliJcYb2XH955Qz/xjRbr097IVAkH0guelYKCJMvYa82jJAsiFqVgBG4E0ifzkyrdqHQ+izzjN9iNutMydRk7HMApBa9XHCzY6wDiEbn+SM84xMB18fxyHY0PElBtiNdlAu8DmPB9e3vSp7ipI/ysJZvmfSI3MB1MpBlMd+mE+5gnG1TzSAx5BaHO/A9db2C2pHi1biIOXDs8/f5ZF3xHA7EgG2IXy1QbbX5r8xzcbo3YEu5JR6sUlucfi6o0PErYOHgc/oOfqfq49MRQ0ruIGJM5kIoKiyhSPL2ZM3XcSzll8RG1MHFQ9Rkh1xfh9u2S8Mc3kAIcW7FrbP73idb9TtTuAu4mYRE1yjmwHwr7u8pBnzTopWVY3EgMTsAoVnQ3Y8Xq7VibrWV1glrnRshlih+/0TtnN0HDCdi5coMX97kGqyLCQaxDl39oQpyEnQjV/aQSdv32YMDiGbdd0477HNr662XZX9WdiH06TYzJi35dL+EQTTyN8YcM6aBq/qwOhUVOUNOokdbwVm31Hyhdjhw/Nn28PQWl5eE0msqe3rF7zFptcNgqjnJ7F+1/+9rsugMM2xPtE1yCQiMRuQJSCKrJxzlxUGsmaiqhKI3/hORiReqcbi3gdKlrVUeuUscYOMMk/icW6ySV1fKxGYYunixz52gDcNCecuKL3on9+Xntsc1BkSHnc9Jb6T2InHoeaF7nklCgHuPAfs4QfZi6NPEWx99+uJ2BG6vtE1GF3CXPYbVFC4kXMFS7YgyLHpfMC782aMXK5OG3S3DmmeBwdqQLOvL+GMJj//aX+m16dPzGDWB2RlK3y4yEHYLB9c/BrxaJPZCwpb0Pf0YOZhavLWlLDHzBKK+ehPoMNnnO6DBz1SydVPw0Yi19WyKN8fSPLG/ztTaxwgS727jM+dstsyqaa1J5vorWH9xvIaexx0775dbATNpbc8Zs55i6gGrOyJPWZwtyJhQAqwie6XutnoqmeXUEcRjhjOgeZ9MoFGfLBRrdaFnjB8UiPQcjOjr2xU7Lhu+KsGuL0cItVtL0GLToCEDdAevmUGsX7pnJJh1a2TcVP12Lq9uUJd4LdUctO5J/rYyr1Be62iAyH1gGxVEBBg7mDTB/FLBVL+qwHM07QqwHNZQsHh4DFLUNekj7BDURZzybma3jOxb08jlCHF9dd9ljGrpr8d4CZSfqu2wG6nKH7jn5FER1YyJvKGD8pEaHaFzctMbU5Gx/qaYC8NUks8uFeqB1qLE5Gq7GQKEG3EtGunKS/loWQqY58MzlnFW9nnGepG79sOQU= X-OriginatorOrg: os.amperecomputing.com X-MS-Exchange-CrossTenant-Network-Message-Id: a89b4120-66dc-4f5f-b8e2-08dbf79e45b0 X-MS-Exchange-CrossTenant-AuthSource: SN4PR01MB7455.prod.exchangelabs.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Dec 2023 03:32:15.3008 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3bc2b170-fd94-476d-b0ce-4229bdc904a7 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: uz7HCNU0kVg1jpTNGtYD8qORLzFZwnOWOWoo/LIoYqY6xFPqeQBwVLQS0ch0Ht73ZgvIJgNsolVPnv5SeTiW8m27jG+A0h7DAFeHQfLcH3o= X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR01MB7784 X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on morse.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (morse.vger.email [0.0.0.0]); Thu, 07 Dec 2023 19:32:38 -0800 (PST) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1784683022442280304 X-GMAIL-MSGID: 1784683022442280304 Commit 2be6b47211e1 ("i2c: aspeed: Acknowledge most interrupts early in interrupt handler") acknowledges most interrupts early before the slave irq handler is executed, except for the "Receive Done Interrupt status" which is acknowledged late in the interrupt. However, it has been observed that the early acknowledgment of "Transmit Done Interrupt Status" (with ACK or NACK) often causes the interrupt to be raised in READ REQUEST state, that shows the "Unexpected ACK on read request." complaint messages. Assuming that the "Transmit Done" interrupt should only be acknowledged once it is truly processed, this commit fixes that issue by acknowledging interrupts for both ACK and NACK cases late in the interrupt handler. Fixes: 2be6b47211e1 ("i2c: aspeed: Acknowledge most interrupts early in interrupt handler") Signed-off-by: Quan Nguyen Reviewed-by: Andrew Jeffery Reviewed-by: Andi Shyti --- v3: + Fix the unconditinal write when ack the irqs [Andrew] + Refactor the code to enhance code readability [Quan] + Fix grammar in commit message [Quan] v2: + Split to separate series [Joel] + Added the Fixes line [Joel] + Fixed multiline comment [Joel] + Refactor irq clearing code [Joel, Guenter] + Revised commit message [Joel] + Revised commit message [Quan] + About a note to remind why the readl() should immediately follow the writel() to fix the race condition when clearing irq status from commit c926c87b8e36 ("i2c: aspeed: Avoid i2c interrupt status clear race condition"), I think it looks straight forward in this patch and decided not to add that note. [Joel] v1: + First introduced in https://lore.kernel.org/all/20210519074934.20712-1-quan@os.amperecomputing.com/ --- drivers/i2c/busses/i2c-aspeed.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index 1c2a4f4c4e1b..967a26dd4ffa 100644 --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -617,13 +617,19 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id) { struct aspeed_i2c_bus *bus = dev_id; - u32 irq_received, irq_remaining, irq_handled; + u32 irq_received, irq_remaining, irq_handled, irq_ack_last; spin_lock(&bus->lock); irq_received = readl(bus->base + ASPEED_I2C_INTR_STS_REG); - /* Ack all interrupts except for Rx done */ - writel(irq_received & ~ASPEED_I2CD_INTR_RX_DONE, - bus->base + ASPEED_I2C_INTR_STS_REG); + + /* + * Early acking of INTR_RX_DONE and INTR_TX_[ACK|NAK] would indicate HW to + * start receiving or sending new data, and this may cause a race condition + * as the irq handler has not yet handled these irqs but is being acked. + * Let's ack them late at the end of the irq handler when those are truly processed. + */ + irq_ack_last = ASPEED_I2CD_INTR_RX_DONE | ASPEED_I2CD_INTR_TX_ACK | ASPEED_I2CD_INTR_TX_NAK; + writel(irq_received & ~irq_ack_last, bus->base + ASPEED_I2C_INTR_STS_REG); readl(bus->base + ASPEED_I2C_INTR_STS_REG); irq_received &= ASPEED_I2CD_INTR_RECV_MASK; irq_remaining = irq_received; @@ -667,12 +673,11 @@ static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id) "irq handled != irq. expected 0x%08x, but was 0x%08x\n", irq_received, irq_handled); - /* Ack Rx done */ - if (irq_received & ASPEED_I2CD_INTR_RX_DONE) { - writel(ASPEED_I2CD_INTR_RX_DONE, - bus->base + ASPEED_I2C_INTR_STS_REG); + if (irq_received & irq_ack_last) { + writel(irq_received & irq_ack_last, bus->base + ASPEED_I2C_INTR_STS_REG); readl(bus->base + ASPEED_I2C_INTR_STS_REG); } + spin_unlock(&bus->lock); return irq_remaining ? IRQ_NONE : IRQ_HANDLED; }