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