From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Delvare Subject: Re: [PATCH] MIPS: Octeon: Register EEPROM device on the I2C bus Date: Fri, 5 Mar 2010 12:42:00 +0100 Message-ID: <20100305124200.6f6eccfc@hyperion.delvare> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4B90E83A.5020106-Mmb7MZpHnFY@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Michael Lawnick Cc: Yang Shi , Linux I2C List-Id: linux-i2c@vger.kernel.org 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 ;) -- Jean Delvare