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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 A2FC6C2BABC for ; Tue, 7 Apr 2020 09:28:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 74B9B20730 for ; Tue, 7 Apr 2020 09:28:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728049AbgDGJ2F (ORCPT ); Tue, 7 Apr 2020 05:28:05 -0400 Received: from esa2.mentor.iphmx.com ([68.232.141.98]:43934 "EHLO esa2.mentor.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726720AbgDGJ2E (ORCPT ); Tue, 7 Apr 2020 05:28:04 -0400 IronPort-SDR: ZGroXjKKri4pdlkPsMBB5WOGAA9A/2ZUSD9A2NN8wB33pfg3DRYaYww7P1xOd6TDstN5jp/RUj JPl2/8fjbi7dgiWganQbgzpzrPP+4lqMXP1qhIwxc9rOfer8AyrWk6fyvyh2NAApLCay/wOKKZ +vsjBcZlXMuv5RO6fjcGsyls0rZ0jXR4dySZitIEPCpPnqG/FqGqsCQRRRMZcnSDs5QEs0Lxmk nilFl9oZUl7wvSayhuAZSO3RSSkw/97fMIpMjwU6EiabXXo5h6lucRvZY1yOq44fQnzO3z6h4f ryg= X-IronPort-AV: E=Sophos;i="5.72,353,1580803200"; d="scan'208";a="47422403" Received: from orw-gwy-01-in.mentorg.com ([192.94.38.165]) by esa2.mentor.iphmx.com with ESMTP; 07 Apr 2020 01:27:55 -0800 IronPort-SDR: mYeNVzai53H22P+qIY4UWkBDzXs+r/WaUZR9bewhQ75mLiPoLVGVRdI+H4hnIqxVyYkM+95MyN MkVgRUzhYICePJ+MQ11f6JYgxytY1QzRUvjEqp7+WQzAijIEfHMMRgcDlDLnmKGKHqFxXvsDf+ 40EiOI94KMnQtSJPoRsKcnmDrlc6I6hs1042BmuwXJQ5DgGtOaH9wopqyHDQKy4//8g1hZjQx9 oK6roMKzLrephT0E+H7fTdBMZWZBUHd1N1ByITwBfVpWwTGtaEegxCzcMhkCdOU1uHgCvur7r4 jHw= Subject: Re: [PATCH v10 43/55] dt-bindings: input: atmel: support to set max bytes transferred To: Dmitry Osipenko , , , , , CC: , , , References: <20200331105051.58896-1-jiada_wang@mentor.com> <20200331105051.58896-44-jiada_wang@mentor.com> From: "Wang, Jiada" Message-ID: <9b98a3fc-b7ee-fc01-dc5c-248df507d4a2@mentor.com> Date: Tue, 7 Apr 2020 18:27:49 +0900 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-ClientProxiedBy: svr-orw-mbx-02.mgc.mentorg.com (147.34.90.202) To svr-orw-mbx-01.mgc.mentorg.com (147.34.90.201) Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Hi Dmitry On 2020/04/01 23:38, Dmitry Osipenko wrote: > 31.03.2020 13:50, Jiada Wang пишет: >> Add support to set max bytes transferred in an i2c transaction >> >> Signed-off-by: Jiada Wang >> --- >> Documentation/devicetree/bindings/input/atmel,maxtouch.txt | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/input/atmel,maxtouch.txt b/Documentation/devicetree/bindings/input/atmel,maxtouch.txt >> index 126266891cdc..37a798cab0dd 100644 >> --- a/Documentation/devicetree/bindings/input/atmel,maxtouch.txt >> +++ b/Documentation/devicetree/bindings/input/atmel,maxtouch.txt >> @@ -45,6 +45,8 @@ Optional properties for main touchpad device: >> >> - atmel,input_name: Override name of input device from the default. >> >> +- atmel,mtu: Maximum number of bytes that can read/transferred in an i2c transaction >> + >> Example: >> >> touch@4b { >> @@ -52,4 +54,5 @@ Example: >> reg = <0x4b>; >> interrupt-parent = <&gpio>; >> interrupts = ; >> + atmel,mtu = <200> >> }; >> > > Is this a software (firmware) limitation which varies from version to > version? > the timeout issue trying to be addressed in this patch is from software, one of our board a Serializer/Deserializer bridge exists between the SoC (imx6) and the Atmel touch controller. imx6 i2c controller driver has a timeout value(100ms) for each i2c transaction, Large i2c read transaction failed to complete within this timeout value and therefore imx6 i2c controller driver aborts the transaction and returns failure. Therefore this patch was created to split the large i2c transaction into smaller chunks which can complete within the timeout defined by i2c controller driver. Thanks, Jiada > If the limitation is per-hardware version, then perhaps should be better > to have a hardcoded per-hardware table of limits in the driver? >