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=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 4CC42ECDFB6 for ; Tue, 1 Oct 2019 07:10:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21D4F215EA for ; Tue, 1 Oct 2019 07:10:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=st.com header.i=@st.com header.b="nCPPdoIA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732846AbfJAHKo (ORCPT ); Tue, 1 Oct 2019 03:10:44 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:40334 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1732676AbfJAHKo (ORCPT ); Tue, 1 Oct 2019 03:10:44 -0400 Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx08-00178001.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id x917AX0Y016964; Tue, 1 Oct 2019 09:10:34 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=st.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=STMicroelectronics; bh=pOPCPe7TD98TjMLQMWtDzzXnRWgJwMhoU21tYTK3+oE=; b=nCPPdoIAWmY+E3PbFphqiQxVifYVDuBTXtC5iPxIU5allVbyAEFfITnniTgis2ajDjkc LcD3ftoHW4m2CBJlLzotb3awNS3nZ/WHGSzkwFw868CNfwA9SoJ+dZQ4b/RZ7iGkC/zs AsS2SPxHV2W5PqwRXi/xY0g9y4UHKP4AKNn5i2ScXSB9LKX3yDPrnwJCrMjQdB6WZ3nq UYf6wy9yoSsMnZ1Jbro6OL0vgMZeLMkBmiEpf6GwtisJm1RJsl5GNa20w/nqI57K4rdV 4jFReLcBKpWmfWE3JqZxoMsxQmHgq1ChJESJyrcMyMva1cEZAAdmBQfqIZhKfApNhG2P dg== Received: from beta.dmz-ap.st.com (beta.dmz-ap.st.com [138.198.100.35]) by mx08-00178001.pphosted.com with ESMTP id 2v9xdgq2kw-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Tue, 01 Oct 2019 09:10:34 +0200 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-ap.st.com (STMicroelectronics) with ESMTP id 4334F4C; Tue, 1 Oct 2019 07:10:15 +0000 (GMT) Received: from Webmail-eu.st.com (sfhdag5node2.st.com [10.75.127.14]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 596492AB7C3; Tue, 1 Oct 2019 09:10:15 +0200 (CEST) Received: from [10.48.1.171] (10.75.127.44) by SFHDAG5NODE2.st.com (10.75.127.14) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 1 Oct 2019 09:10:14 +0200 Subject: Re: [PATCH] i2c: i2c-stm32f7: fix first byte to send in slave mode To: Fabrice Gasnier , CC: , , , , , References: <1569857281-19419-1-git-send-email-fabrice.gasnier@st.com> From: Pierre Yves MORDRET Message-ID: <144ffb23-a56e-c60f-8c50-802921755835@st.com> Date: Tue, 1 Oct 2019 09:10:14 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <1569857281-19419-1-git-send-email-fabrice.gasnier@st.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.75.127.44] X-ClientProxiedBy: SFHDAG8NODE2.st.com (10.75.127.23) To SFHDAG5NODE2.st.com (10.75.127.14) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,1.0.8 definitions=2019-10-01_03:2019-09-30,2019-10-01 signatures=0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Reviewed-by: Pierre-Yves MORDRET Thx On 9/30/19 5:28 PM, Fabrice Gasnier wrote: > The slave-interface documentation [1] states "the bus driver should > transmit the first byte" upon I2C_SLAVE_READ_REQUESTED slave event: > - 'val': backend returns first byte to be sent > The driver currently ignores the 1st byte to send on this event. > > Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support") > > [1] https://www.kernel.org/doc/Documentation/i2c/slave-interface > > Signed-off-by: Fabrice Gasnier > --- > drivers/i2c/busses/i2c-stm32f7.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c > index 266d1c2..0af9219 100644 > --- a/drivers/i2c/busses/i2c-stm32f7.c > +++ b/drivers/i2c/busses/i2c-stm32f7.c > @@ -1192,6 +1192,8 @@ static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev) > STM32F7_I2C_CR1_TXIE; > stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask); > > + /* Write 1st data byte */ > + writel_relaxed(value, base + STM32F7_I2C_TXDR); > } else { > /* Notify i2c slave that new write transfer is starting */ > i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value); >