From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomoya MORINAGA Subject: Re: [PATCH 3/7] i2c-eg20t: delete 10bit access processing Date: Thu, 22 Sep 2011 09:13:46 +0900 Message-ID: <4E7A7DBA.3020406@dsn.okisemi.com> References: <1316591509-4433-1-git-send-email-tomoya-linux@dsn.okisemi.com> <1316591509-4433-3-git-send-email-tomoya-linux@dsn.okisemi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Jeffrey (Sheng-Hui) Chu" Cc: Jean Delvare , Ben Dooks , "linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Qi Wang , "yong.y.wang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "joel.clark-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "kok.howg.ewe-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "toshiharu-linux-ECg8zkTtlr0C6LszWs/t0g@public.gmane.org" List-Id: linux-i2c@vger.kernel.org (2011/09/22 0:42), Jeffrey (Sheng-Hui) Chu wrote: > There is i2c device coming out that uses 10-bit address. Thank you for your information. We want to test 10-bit mode using the device. So let me know the device information ? Anyway, Now, kernel i2c-core is EXPERIMENTAL stage for 10-bit mode like below. (Documentation/i2c/ten-bit-addresses) WARNING! The current 10 bit address support is EXPERIMENTAL. There are several places in the code that will cause SEVERE PROBLEMS with 10 bit addresses, even though there is some basic handling and hooks. Also, almost no supported adapter handles the 10 bit addresses correctly. As soon as a real 10 bit address device is spotted 'in the wild', we can and will add proper support. Right now, 10 bit address devices are defined by the I2C protocol, but we have never seen a single device which supports them. After kernel supports 10bit-mode formally, we will add the function to i2c-eg20t again. Thanks, tomoya From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751361Ab1IVANw (ORCPT ); Wed, 21 Sep 2011 20:13:52 -0400 Received: from sm-d311v.smileserver.ne.jp ([203.211.202.206]:44917 "EHLO sm-d311v.smileserver.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751059Ab1IVANv (ORCPT ); Wed, 21 Sep 2011 20:13:51 -0400 Message-ID: <4E7A7DBA.3020406@dsn.okisemi.com> Date: Thu, 22 Sep 2011 09:13:46 +0900 From: Tomoya MORINAGA User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ja; rv:1.9.2.17) Gecko/20110414 Thunderbird/3.1.10 MIME-Version: 1.0 To: "Jeffrey (Sheng-Hui) Chu" CC: Jean Delvare , Ben Dooks , "linux-i2c@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Qi Wang , "yong.y.wang@intel.com" , "joel.clark@intel.com" , "kok.howg.ewe@intel.com" , "toshiharu-linux@dsn.okisemi.com" Subject: Re: [PATCH 3/7] i2c-eg20t: delete 10bit access processing References: <1316591509-4433-1-git-send-email-tomoya-linux@dsn.okisemi.com> <1316591509-4433-3-git-send-email-tomoya-linux@dsn.okisemi.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (2011/09/22 0:42), Jeffrey (Sheng-Hui) Chu wrote: > There is i2c device coming out that uses 10-bit address. Thank you for your information. We want to test 10-bit mode using the device. So let me know the device information ? Anyway, Now, kernel i2c-core is EXPERIMENTAL stage for 10-bit mode like below. (Documentation/i2c/ten-bit-addresses) WARNING! The current 10 bit address support is EXPERIMENTAL. There are several places in the code that will cause SEVERE PROBLEMS with 10 bit addresses, even though there is some basic handling and hooks. Also, almost no supported adapter handles the 10 bit addresses correctly. As soon as a real 10 bit address device is spotted 'in the wild', we can and will add proper support. Right now, 10 bit address devices are defined by the I2C protocol, but we have never seen a single device which supports them. After kernel supports 10bit-mode formally, we will add the function to i2c-eg20t again. Thanks, tomoya