From patchwork Fri Dec 15 17:06:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alain Volmat X-Patchwork-Id: 13494694 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 0767AC4332F for ; Fri, 15 Dec 2023 17:08:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=S00t2n+oPUIMHSL04YXFl+JXVevpWM785erb8TmS/vs=; b=oEUei0o7EjkIn6 zaQM31hqjWqajlSXumXe90CKjMabFdwIEVZ7QaqfvikfpJpUfSjy8UeM+NK+aZT69C8Hfampg9MZ3 TPAnb/p/gWpHriOdWlYwi0Ls/pqrHsu+/qsq8UKzrTjDG4TNhiloW1Pi6jOfAiua3SOgHLttBJTRB yfZT+8qenZd7+7RcgV14mWOPynN4hxcmTFsmnQ4BP+shH1S3wcR1IjQgGaoDD8UE62c/AF2eFRstl TEJmF3/LUasTu1glEHw2GPWLoVI/9rpuq3kSUaeDd85qn6qQignFKVyS2rvHJalazvQ5pJVeQZH3r OXCYa99QN5z6ostOHZtA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rEBfG-003yjE-2f; Fri, 15 Dec 2023 17:07:54 +0000 Received: from mx08-00178001.pphosted.com ([91.207.212.93] helo=mx07-00178001.pphosted.com) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rEBf7-003ye6-2m for linux-arm-kernel@lists.infradead.org; Fri, 15 Dec 2023 17:07:48 +0000 Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.17.1.22/8.17.1.22) with ESMTP id 3BFFI6IN006661; Fri, 15 Dec 2023 18:07:38 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding:content-type; s= selector1; bh=wy7wgUsJaX5XQsgjxRGUwCP4v90sJL58dgNnlCma76Q=; b=6P YZeb4mAFTmJbCRGgpyG+2KxgLiLOKS3xn6He9DB0C1O8DAgTjaBb6Vh/UmzAmChg O7QPL4SMRhQtEr7rgAw7iVhjGOI5/YgJYSzgkWxjAYTgrQ9isQguNRvQP3lJx/H+ zKluCX9d8DsD37xYceCftveaXf4BrHrqFugwa1OYEUGDOX3zYVn1iJsipAUvprxU P0npu8PBlMgiEr9MA6VcNqWFR6tm/KicmigpYP3ZjcdMBOuQ+AbHb6juoYpx8N5p nn/5CnOXQgOgJdFdl6lCb+71duxH5cW3HcQvKzvT1AKxShXB3IBiiM4bvCzZLxXX n2v/CugSUAzFE6eatjFw== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3uvg0hagea-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 15 Dec 2023 18:07:38 +0100 (CET) Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 88F13100052; Fri, 15 Dec 2023 18:07:37 +0100 (CET) Received: from Webmail-eu.st.com (shfdag1node1.st.com [10.75.129.69]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 7FC6623BDFD; Fri, 15 Dec 2023 18:07:37 +0100 (CET) Received: from localhost (10.129.178.213) by SHFDAG1NODE1.st.com (10.75.129.69) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Fri, 15 Dec 2023 18:07:37 +0100 From: Alain Volmat To: Andi Shyti , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Maxime Coquelin , Alexandre Torgue , Pierre-Yves MORDRET , Alain Volmat CC: Conor Dooley , , , , , Subject: [PATCH v3 2/9] i2c: stm32f7: perform most of irq job in threaded handler Date: Fri, 15 Dec 2023 18:06:06 +0100 Message-ID: <20231215170617.95868-3-alain.volmat@foss.st.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231215170617.95868-1-alain.volmat@foss.st.com> References: <20231215170617.95868-1-alain.volmat@foss.st.com> MIME-Version: 1.0 X-Originating-IP: [10.129.178.213] X-ClientProxiedBy: SHFCAS1NODE2.st.com (10.75.129.73) To SHFDAG1NODE1.st.com (10.75.129.69) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-15_10,2023-12-14_01,2023-05-22_02 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231215_090746_176100_3B7BE133 X-CRM114-Status: GOOD ( 21.80 ) 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 The irq handling is currently split between the irq handler and the threaded irq handler. Some of the handling (such as dma related stuffs) done within the irq handler might sleep or take some time leading to issues if the kernel is built with realtime constraints. In order to fix that, perform an overall rework to perform most of the job within the threaded handler and only keep fifo access in the non threaded handler. Signed-off-by: Alain Volmat Reviewed-by: Andi Shyti --- drivers/i2c/busses/i2c-stm32f7.c | 126 ++++++++++++++----------------- 1 file changed, 56 insertions(+), 70 deletions(-) diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index d99f152ac727..dde70e7ec722 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -1497,17 +1497,11 @@ static irqreturn_t stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev *i2c_dev) static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data) { struct stm32f7_i2c_dev *i2c_dev = data; - struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; - struct stm32_i2c_dma *dma = i2c_dev->dma; - void __iomem *base = i2c_dev->base; - u32 status, mask; - int ret = IRQ_HANDLED; + u32 status; - /* Check if the interrupt if for a slave device */ - if (!i2c_dev->master_mode) { - ret = stm32f7_i2c_slave_isr_event(i2c_dev); - return ret; - } + /* Check if the interrupt is for a slave device */ + if (!i2c_dev->master_mode) + return IRQ_WAKE_THREAD; status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR); @@ -1519,6 +1513,29 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data) if (status & STM32F7_I2C_ISR_RXNE) stm32f7_i2c_read_rx_data(i2c_dev); + /* Wake up the thread if other flags are raised */ + if (status & + (STM32F7_I2C_ISR_NACKF | STM32F7_I2C_ISR_STOPF | + STM32F7_I2C_ISR_TC | STM32F7_I2C_ISR_TCR)) + return IRQ_WAKE_THREAD; + + return IRQ_HANDLED; +} + +static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data) +{ + struct stm32f7_i2c_dev *i2c_dev = data; + struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; + struct stm32_i2c_dma *dma = i2c_dev->dma; + void __iomem *base = i2c_dev->base; + u32 status, mask; + int ret; + + if (!i2c_dev->master_mode) + return stm32f7_i2c_slave_isr_event(i2c_dev); + + status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR); + /* NACK received */ if (status & STM32F7_I2C_ISR_NACKF) { dev_dbg(i2c_dev->dev, "<%s>: Receive NACK (addr %x)\n", @@ -1531,33 +1548,28 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data) f7_msg->result = -ENXIO; } - /* STOP detection flag */ - if (status & STM32F7_I2C_ISR_STOPF) { - /* Disable interrupts */ - if (stm32f7_i2c_is_slave_registered(i2c_dev)) - mask = STM32F7_I2C_XFER_IRQ_MASK; + if (status & STM32F7_I2C_ISR_TCR) { + if (f7_msg->smbus) + stm32f7_i2c_smbus_reload(i2c_dev); else - mask = STM32F7_I2C_ALL_IRQ_MASK; - stm32f7_i2c_disable_irq(i2c_dev, mask); - - /* Clear STOP flag */ - writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR); - - if (i2c_dev->use_dma && !f7_msg->result) { - ret = IRQ_WAKE_THREAD; - } else { - i2c_dev->master_mode = false; - complete(&i2c_dev->complete); - } + stm32f7_i2c_reload(i2c_dev); } /* Transfer complete */ if (status & STM32F7_I2C_ISR_TC) { + /* Wait for dma transfer completion before sending next message */ + if (i2c_dev->use_dma && !f7_msg->result) { + ret = wait_for_completion_timeout(&i2c_dev->dma->dma_complete, HZ); + if (!ret) { + dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__); + stm32f7_i2c_disable_dma_req(i2c_dev); + dmaengine_terminate_async(dma->chan_using); + f7_msg->result = -ETIMEDOUT; + } + } if (f7_msg->stop) { mask = STM32F7_I2C_CR2_STOP; stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask); - } else if (i2c_dev->use_dma && !f7_msg->result) { - ret = IRQ_WAKE_THREAD; } else if (f7_msg->smbus) { stm32f7_i2c_smbus_rep_start(i2c_dev); } else { @@ -1567,47 +1579,18 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data) } } - if (status & STM32F7_I2C_ISR_TCR) { - if (f7_msg->smbus) - stm32f7_i2c_smbus_reload(i2c_dev); + /* STOP detection flag */ + if (status & STM32F7_I2C_ISR_STOPF) { + /* Disable interrupts */ + if (stm32f7_i2c_is_slave_registered(i2c_dev)) + mask = STM32F7_I2C_XFER_IRQ_MASK; else - stm32f7_i2c_reload(i2c_dev); - } - - return ret; -} - -static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data) -{ - struct stm32f7_i2c_dev *i2c_dev = data; - struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; - struct stm32_i2c_dma *dma = i2c_dev->dma; - u32 status; - int ret; - - /* - * Wait for dma transfer completion before sending next message or - * notity the end of xfer to the client - */ - ret = wait_for_completion_timeout(&i2c_dev->dma->dma_complete, HZ); - if (!ret) { - dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__); - stm32f7_i2c_disable_dma_req(i2c_dev); - dmaengine_terminate_async(dma->chan_using); - f7_msg->result = -ETIMEDOUT; - } + mask = STM32F7_I2C_ALL_IRQ_MASK; + stm32f7_i2c_disable_irq(i2c_dev, mask); - status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR); + /* Clear STOP flag */ + writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR); - if (status & STM32F7_I2C_ISR_TC) { - if (f7_msg->smbus) { - stm32f7_i2c_smbus_rep_start(i2c_dev); - } else { - i2c_dev->msg_id++; - i2c_dev->msg++; - stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg); - } - } else { i2c_dev->master_mode = false; complete(&i2c_dev->complete); } @@ -1615,7 +1598,7 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data) return IRQ_HANDLED; } -static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) +static irqreturn_t stm32f7_i2c_isr_error_thread(int irq, void *data) { struct stm32f7_i2c_dev *i2c_dev = data; struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg; @@ -2202,8 +2185,11 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) if (ret) return dev_err_probe(&pdev->dev, ret, "Failed to request irq event\n"); - ret = devm_request_irq(&pdev->dev, irq_error, stm32f7_i2c_isr_error, 0, - pdev->name, i2c_dev); + ret = devm_request_threaded_irq(&pdev->dev, irq_error, + NULL, + stm32f7_i2c_isr_error_thread, + IRQF_ONESHOT, + pdev->name, i2c_dev); if (ret) return dev_err_probe(&pdev->dev, ret, "Failed to request irq error\n");