From patchwork Fri Dec 8 16:47:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alain Volmat X-Patchwork-Id: 13485678 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 48F42C4167B for ; Fri, 8 Dec 2023 16:48:29 +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=WiqiqQuOoNYSlj4J87GD3uwMstf+kdAbEO3laT3e4eY=; b=x4d51IqGckyaoc nJYfTrFJm1GyDN8WDnjsrrC2HfWTHyVolmQ6OhFrejW8OXzt21DQwi+5Spn0LHQu0SwYLp+Dizs8b 7vvWCS+n0AJ27D88nO0tI7CqT8TDjiHpqRoDt8UhzdwLbXFl0sCarg0kHjFfSnGsFg29Bydd2Enxk tZ58CyLkVeMcL7qNYsxN/YUVaLWlT/ldHHlt831YCRckU8HvxgVTBsrUIonDTsLKCBTsYl9TP9uWv bXl+pFAl/EXce7pZcfHPU1NLYRh94q0ADX2Nu2C/UjuHxSaAYLxYjnW2sBy3HR/3H3PLswINK6akT 7EniEaApn5i+qQ8X5+7Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rBe18-00G4tD-1S; Fri, 08 Dec 2023 16:47:58 +0000 Received: from mx07-00178001.pphosted.com ([185.132.182.106]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rBe10-00G4of-2E for linux-arm-kernel@lists.infradead.org; Fri, 08 Dec 2023 16:47:52 +0000 Received: from pps.filterd (m0288072.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.17.1.22/8.17.1.22) with ESMTP id 3B8F1Sf8015608; Fri, 8 Dec 2023 17:47:43 +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=JtOvQS+6evVSFOg4x1qpS4jVWP7j9KTB9w21qfsiDm4=; b=iq rEFpzTt8M2Ry33IZgKc2j5xnKYYhlDgTBgGPRQZ9R40niuCWejU4STSQNci8UVJe Uef1/JY2WfiM+ZXO6MNTUryCO85xdFvoAfAAoQp7DXuEwdAQc3m4q6tfnP3VBfgt mptRpotrOzdjz5uWA3nDjeRkMw7Spi4UKkcqVdhTKif85rM8r8SxpZe8fozBQMGl 5rssETWK3/lQNded0a2u1k9HIXVWAiQhDKFDcO2ZyC5JGrr6eeexpoGCQCEO1cgb bZ5mUezkVuuYLtpAYC6TE9vMkzjx8wEWj34ZOWoRBi2i47d1yRQCY0Q9Nl8EDg0j +otFd735pPFXBJnwINKA== 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 3utd2gnfrk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 08 Dec 2023 17:47:43 +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 B637E100056; Fri, 8 Dec 2023 17:47:42 +0100 (CET) Received: from Webmail-eu.st.com (shfdag1node1.st.com [10.75.129.69]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id AA79223692D; Fri, 8 Dec 2023 17:47:42 +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, 8 Dec 2023 17:47:42 +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 , Rob Herring , , , , , Subject: [PATCH v2 1/7] i2c: stm32f7: perform most of irq job in threaded handler Date: Fri, 8 Dec 2023 17:47:10 +0100 Message-ID: <20231208164719.3584028-2-alain.volmat@foss.st.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231208164719.3584028-1-alain.volmat@foss.st.com> References: <20231208164719.3584028-1-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=2023-12-08_11,2023-12-07_01,2023-05-22_02 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231208_084751_027643_DF40E67F X-CRM114-Status: GOOD ( 21.45 ) 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 983509936727..34dcc370e615 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; @@ -2205,8 +2188,11 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) return ret; } - 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) { dev_err(&pdev->dev, "Failed to request irq error %i\n", irq_error);