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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_2 autolearn=no 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 E6117C3A5A2 for ; Thu, 22 Aug 2019 08:24:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3DBD23784 for ; Thu, 22 Aug 2019 08:24:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732336AbfHVIYx (ORCPT ); Thu, 22 Aug 2019 04:24:53 -0400 Received: from Mailgw01.mediatek.com ([1.203.163.78]:43278 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1731207AbfHVIYx (ORCPT ); Thu, 22 Aug 2019 04:24:53 -0400 X-UUID: 01fbca1311e54c78adea42e8c0d5164f-20190822 X-UUID: 01fbca1311e54c78adea42e8c0d5164f-20190822 Received: from mtkcas32.mediatek.inc [(172.27.4.253)] by mailgw01.mediatek.com (envelope-from ) (mailgw01.mediatek.com ESMTP with TLS) with ESMTP id 1885262594; Thu, 22 Aug 2019 16:24:38 +0800 Received: from mtkcas09.mediatek.inc (172.21.101.178) by MTKMBS31N2.mediatek.inc (172.27.4.87) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Thu, 22 Aug 2019 16:24:35 +0800 Received: from [172.21.77.4] (172.21.77.4) by mtkcas09.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Thu, 22 Aug 2019 16:24:35 +0800 Message-ID: <1566462278.26641.1.camel@mtksdaap41> Subject: Re: [PATCH RESEND] i2c: mediatek: disable zero-length transfers for mt8183 From: Yingjoe Chen To: Hsin-Yi Wang CC: Wolfram Sang , , Nicolas Boichat , Alexandru M Stan , Jun Gao , , , , Matthias Brugger , Thomas Gleixner , Qii Wang Date: Thu, 22 Aug 2019 16:24:38 +0800 In-Reply-To: <20190822055737.142384-1-hsinyi@chromium.org> References: <20190822055737.142384-1-hsinyi@chromium.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-TM-SNTS-SMTP: CDD14A64F1E5A4DF5E573825EDBC482C6C80C91A52820B01E0AE08A9F54881602000:8 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2019-08-22 at 13:57 +0800, Hsin-Yi Wang wrote: > When doing i2cdetect quick write mode, we would get transfer > error ENOMEM, and i2cdetect shows there's no device at the address. > Quoting from mt8183 datasheet, the number of transfers to be > transferred in one transaction should be set to bigger than 1, > so we should forbid zero-length transfer and update functionality. <...> > @@ -933,8 +942,8 @@ static int mtk_i2c_probe(struct platform_device *pdev) > i2c->dev = &pdev->dev; > i2c->adap.dev.parent = &pdev->dev; > i2c->adap.owner = THIS_MODULE; > - i2c->adap.algo = &mtk_i2c_algorithm; > i2c->adap.quirks = i2c->dev_comp->quirks; > + i2c->adap.algo = &mtk_i2c_algorithm; > i2c->adap.timeout = 2 * HZ; > i2c->adap.retries = 1; > Why do you need to change this part? Joe.C