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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 CC61AC3279B for ; Tue, 10 Jul 2018 23:40:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D8062098B for ; Tue, 10 Jul 2018 23:40:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8D8062098B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.crashing.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732469AbeGJXl1 (ORCPT ); Tue, 10 Jul 2018 19:41:27 -0400 Received: from gate.crashing.org ([63.228.1.57]:57312 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732409AbeGJXl1 (ORCPT ); Tue, 10 Jul 2018 19:41:27 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id w6ANdFwe014016; Tue, 10 Jul 2018 18:39:17 -0500 Message-ID: Subject: Re: [PATCH v11 5/8] i2c: fsi: Add transfer implementation From: Benjamin Herrenschmidt To: Eddie James , Wolfram Sang Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, robh+dt@kernel.org, joel@jms.id.au, mark.rutland@arm.com, gregkh@linuxfoundation.org, rdunlap@infradead.org, andy.shevchenko@gmail.com, peda@axentia.se Date: Wed, 11 Jul 2018 09:39:15 +1000 In-Reply-To: References: <1530816030-13010-1-git-send-email-eajames@linux.vnet.ibm.com> <1530816030-13010-6-git-send-email-eajames@linux.vnet.ibm.com> <20180709224114.4h47enyt4tucqcou@ninjato> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.3 (3.28.3-1.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2018-07-10 at 12:52 -0500, Eddie James wrote: > > On 07/09/2018 05:41 PM, Wolfram Sang wrote: > > > + cmd |= FIELD_PREP(I2C_CMD_ADDR, msg->addr >> 1); > > > > I just noticed this and wonder: Don't you need the LSB of the address? > > It is not the RW flag, this is encoded in msg->flags. > > So, the hardware interprets the LSB as the RW flag. It wouldn't be > possible to have a device addressed with the LSB set on this I2C master. What do you mean ? That doesn't sound right... > > > > > Also, no seperate handling for 10 bit addresses? Technically, 7-bit 0x50 > > is different on the wire from 10-bit 0x050. This is minor, though. There > > are no 10-bit devices out there. Still, did you test 10-bit support? > > Indeed, real 10-bit addresses require some additional manipulation of > this I2C master in order to work. We don't support it right now. > > Thanks, > Eddie > > > > > Rest looks good. > >