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 X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D7AAC433EF for ; Thu, 23 Sep 2021 08:38:23 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id DB58C6109E for ; Thu, 23 Sep 2021 08:38:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org DB58C6109E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=foss.st.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org 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:In-Reply-To:MIME-Version:Date: Message-ID:From:References:CC:To:Subject:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=wdluKS1p4Yk3xrrwB7IS6VR43yWZXz7YOXDCS5BFgg4=; b=frALosTbB9b0g85I1SisggGBoL sZrUX7NsPKORhrNM4D1qsvpW5Keu2VDrH2sgBYlDzisNfjuF7KaZMC7sX8yN+uNH2h4VFFRTrTZod MmFnJ7cp9eUpNFNMFuPqBiejzK3h1zCRfQHPBasSkjAKJadZFMvVRAbD6ugw3ZmtEWVI39B9Qu91S NJeynN+lGxNermCql+2kx2Bq5bnu6iexfLP/k1jSsed7R01xSm+PRkNKAYYAaa5I5tK3oo7UNQ1oW mH5Ie9BgrKjLjhPIx2suH1hz4Vr81DY6c+2m+pR4wtihwgM1wEwzRuIsP98OKzsRfLcrKrCCSAwPJ SlYYT5FA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTKD3-00AeQx-Ei; Thu, 23 Sep 2021 08:36:01 +0000 Received: from mx08-00178001.pphosted.com ([91.207.212.93] helo=mx07-00178001.pphosted.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTKCz-00AeQS-98 for linux-arm-kernel@lists.infradead.org; Thu, 23 Sep 2021 08:35:59 +0000 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 18N8LlPQ018755; Thu, 23 Sep 2021 10:35:49 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=selector1; bh=L5H5CURqiC+E8MrIIzttcWBAvlrXfytbBrr7u7fLG7Q=; b=ofvK/fJbMbdi4tBStttl2e72kQDWXN6G+JoT+RFgnGcX80lVjft7SjPV2iROp92iMmdk +2zDigfWXFxnOze3TSX5IuBjpS+GlQZxlHSQlQYBYBfKIPQ2rsrO45thwBr2WQZRA0UF HM0H4j8MmfQto7ALT32fC6VrwBHPgkqvTDd9YMWgTzyUo5U6VzTbsJ77O+Aa7IvzuWfy dcCFD2/D8LXuAdgMvV1Pf8tnS60b44zKyHNJKe1q7qSSXlXyR0U3AbIPTExzYpcsWZ6W QZjLwURzuVnY6Pgf96L6ZXh85G9LYg1t6ArG0UuzAXx5tNhNnR5wvhNl1MAi4a1e8Wgp xQ== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 3b8gdra15s-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 23 Sep 2021 10:35:49 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 37F4210002A; Thu, 23 Sep 2021 10:35:48 +0200 (CEST) Received: from Webmail-eu.st.com (sfhdag2node2.st.com [10.75.127.5]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 27D822248B4; Thu, 23 Sep 2021 10:35:48 +0200 (CEST) Received: from lmecxl1060.lme.st.com (10.75.127.49) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Thu, 23 Sep 2021 10:35:39 +0200 Subject: Re: [PATCH 1/4] i2c: stm32f7: flush TX FIFO upon transfer errors To: Alain Volmat , CC: , , , , , , References: <1632151292-18503-1-git-send-email-alain.volmat@foss.st.com> <1632151292-18503-2-git-send-email-alain.volmat@foss.st.com> From: Pierre Yves MORDRET Message-ID: <9f61c512-559c-146b-9fab-801172cbafaa@foss.st.com> Date: Thu, 23 Sep 2021 10:35:38 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <1632151292-18503-2-git-send-email-alain.volmat@foss.st.com> Content-Language: en-US X-Originating-IP: [10.75.127.49] X-ClientProxiedBy: SFHDAG2NODE3.st.com (10.75.127.6) To SFHDAG2NODE2.st.com (10.75.127.5) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.391,FMLib:17.0.607.475 definitions=2021-09-23_02,2021-09-22_01,2020-04-07_01 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210923_013558_090362_C04EF142 X-CRM114-Status: GOOD ( 24.30 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Alain Reviewed-by: Pierre-Yves MORDRET Regards On 9/20/21 5:21 PM, Alain Volmat wrote: > While handling an error during transfer (ex: NACK), it could > happen that the driver has already written data into TXDR > before the transfer get stopped. > This commit add TXDR Flush after end of transfer in case of error to > avoid sending a wrong data on any other slave upon next transfer. > > Fixes: aeb068c57214 ("i2c: i2c-stm32f7: add driver") > > Signed-off-by: Alain Volmat > --- > drivers/i2c/busses/i2c-stm32f7.c | 20 +++++++++++++++++++- > 1 file changed, 19 insertions(+), 1 deletion(-) > > diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c > index b9b19a2a2ffa..ed977b6f7ab6 100644 > --- a/drivers/i2c/busses/i2c-stm32f7.c > +++ b/drivers/i2c/busses/i2c-stm32f7.c > @@ -1696,6 +1696,16 @@ static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap, > time_left = wait_for_completion_timeout(&i2c_dev->complete, > i2c_dev->adap.timeout); > ret = f7_msg->result; > + if (ret) { > + /* > + * It is possible that some unsent data have already been > + * written into TXDR. To avoid sending old data in a > + * further transfer, flush TXDR in case of any error > + */ > + writel_relaxed(STM32F7_I2C_ISR_TXE, > + i2c_dev->base + STM32F7_I2C_ISR); > + goto pm_free; > + } > > if (!time_left) { > dev_dbg(i2c_dev->dev, "Access to slave 0x%x timed out\n", > @@ -1744,8 +1754,16 @@ static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, > timeout = wait_for_completion_timeout(&i2c_dev->complete, > i2c_dev->adap.timeout); > ret = f7_msg->result; > - if (ret) > + if (ret) { > + /* > + * It is possible that some unsent data have already been > + * written into TXDR. To avoid sending old data in a > + * further transfer, flush TXDR in case of any error > + */ > + writel_relaxed(STM32F7_I2C_ISR_TXE, > + i2c_dev->base + STM32F7_I2C_ISR); > goto pm_free; > + } > > if (!timeout) { > dev_dbg(dev, "Access to slave 0x%x timed out\n", f7_msg->addr); > -- -- ~ Py MORDRET -- _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel