From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yang Shi Subject: Re: [PATCH] MIPS: Octeon: Register EEPROM device on the I2C bus Date: Mon, 08 Mar 2010 12:43:47 +0800 Message-ID: <4B948083.6000703@windriver.com> References: <1267772895-25409-1-git-send-email-yang.shi@windriver.com> <20100305071130.GB21925@pengutronix.de> <4B90B341.9000601@windriver.com> <20100305074155.GD21925@pengutronix.de> <4B90B888.6060005@windriver.com> <20100305095040.6ab4612c@hyperion.delvare> <4B90D85E.6040308@gmx.de> <4B90DF48.50005@windriver.com> <20100305115213.4b504710@hyperion.delvare> <4B90E83A.5020106@gmx.de> <20100305124200.6f6eccfc@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20100305124200.6f6eccfc-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean Delvare Cc: Michael Lawnick , Linux I2C , linux-mips-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org List-Id: linux-i2c@vger.kernel.org Jean Delvare =E5=86=99=E9=81=93: > Hi Michael, > > On Fri, 05 Mar 2010 12:17:14 +0100, Michael Lawnick wrote: > =20 >> Jean Delvare said the following: >> =20 >>> Well, what EEPROM type do you have exactly? 24c64 is for 64 kbit (8 >>> kByte) EEPROMs using 16-bit addressing. You must use the correct ty= pe, >>> otherwise the at24 driver will misbehave. I am a little surprised >>> because originally you went for "eeprom" which is not compatible wi= th >>> "24c64" (8-bit vs. 16-bit addressing). >>> =20 >> Furthermore this brings up another issue: >> 0x50 typically is SPD-eeprom (DDR initialisation). Corrupting the >> contents might make your board unbootable - and using a 16bit driver >> instead of an 8-bit one can corrupt your contents already on >> (positioned) reading! >> =20 > > This is totally correct, but better said loud to the list and the > original poster than only privately to me ;) > =20 Thanks a lot to point out this. I double checked the manual, the eeprom is SPD of the DIMMs. I will rework my patch, then send V2 soon. Regards, Yang From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 08 Mar 2010 05:44:12 +0100 (CET) Received: from mail.windriver.com ([147.11.1.11]:55982 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S1490960Ab0CHEoJ (ORCPT ); Mon, 8 Mar 2010 05:44:09 +0100 Received: from ALA-MAIL03.corp.ad.wrs.com (ala-mail03 [147.11.57.144]) by mail.windriver.com (8.14.3/8.14.3) with ESMTP id o284hnjt015773; Sun, 7 Mar 2010 20:43:49 -0800 (PST) Received: from [128.224.162.222] ([128.224.162.222]) by ALA-MAIL03.corp.ad.wrs.com with Microsoft SMTPSVC(6.0.3790.1830); Sun, 7 Mar 2010 20:43:48 -0800 Message-ID: <4B948083.6000703@windriver.com> Date: Mon, 08 Mar 2010 12:43:47 +0800 From: Yang Shi User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Jean Delvare CC: Michael Lawnick , Linux I2C , linux-mips@linux-mips.org Subject: Re: [PATCH] MIPS: Octeon: Register EEPROM device on the I2C bus References: <1267772895-25409-1-git-send-email-yang.shi@windriver.com> <20100305071130.GB21925@pengutronix.de> <4B90B341.9000601@windriver.com> <20100305074155.GD21925@pengutronix.de> <4B90B888.6060005@windriver.com> <20100305095040.6ab4612c@hyperion.delvare> <4B90D85E.6040308@gmx.de> <4B90DF48.50005@windriver.com> <20100305115213.4b504710@hyperion.delvare> <4B90E83A.5020106@gmx.de> <20100305124200.6f6eccfc@hyperion.delvare> In-Reply-To: <20100305124200.6f6eccfc@hyperion.delvare> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-OriginalArrivalTime: 08 Mar 2010 04:43:49.0127 (UTC) FILETIME=[F1D81170:01CABE79] Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 26140 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: yang.shi@windriver.com Precedence: bulk X-list: linux-mips Jean Delvare 写道: > Hi Michael, > > On Fri, 05 Mar 2010 12:17:14 +0100, Michael Lawnick wrote: > >> Jean Delvare said the following: >> >>> Well, what EEPROM type do you have exactly? 24c64 is for 64 kbit (8 >>> kByte) EEPROMs using 16-bit addressing. You must use the correct type, >>> otherwise the at24 driver will misbehave. I am a little surprised >>> because originally you went for "eeprom" which is not compatible with >>> "24c64" (8-bit vs. 16-bit addressing). >>> >> Furthermore this brings up another issue: >> 0x50 typically is SPD-eeprom (DDR initialisation). Corrupting the >> contents might make your board unbootable - and using a 16bit driver >> instead of an 8-bit one can corrupt your contents already on >> (positioned) reading! >> > > This is totally correct, but better said loud to the list and the > original poster than only privately to me ;) > Thanks a lot to point out this. I double checked the manual, the eeprom is SPD of the DIMMs. I will rework my patch, then send V2 soon. Regards, Yang