From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Norris Subject: Re: PROBLEM: modprobe hang at startup (3.8.x, 3.9.x, IBM x3550) Date: Fri, 17 May 2013 22:18:19 +1000 Message-ID: <20130517121819.GA3165@pyro.melbourne.osa> References: <1368408152.29197.140661229821177.2C1CC406@webmail.messagingengine.com> <20130514231626.GA12961@pyro.melbourne.osa> <20130515112044.753bb7bb@endymion.delvare> <20130515112741.GA23766@pyro.melbourne.osa> <20130515214923.036dabdb@endymion.delvare> <20130516034455.GA19452@pyro.melbourne.osa> <20130517103622.5000d277@endymion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20130517103622.5000d277-R0o5gVi9kd7kN2dkZ6Wm7A@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean Delvare Cc: Daniel Kurtz , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Linux I2C List-Id: linux-i2c@vger.kernel.org On Fri, May 17, 2013 at 10:36:22AM +0200, Jean Delvare wrote: > IPMI is still likely to access the SMBus controller. If there's a BMC > in the machine, it can also access the SMBus slave with its own > controller. It would be good to rule this out by disabling IPMI > completely, removing the BMC from the machine if it has one, and > checking if it makes the issue go away or not. This ended up being easier than I thought. The BMC can't be physically removed, but there is a jumper on the board to disable it. We flipped it and got a message during POST about it not being present. Additionally all IPMI functions did nothing (hung, but interruptable) which is what you'd expect. I think it really is disabled. In this state, I re-ran the previous tests, with identical results. That is: - "modprobe i2c_i801" succeeds - "modprobe i2c_i801 disable_features=0x10" succeeds - With interrupts disabled, "modprobe ics932s401" - With interrupts enabled, "modprobe ics932s401" hangs - With interrupts enabled, "i2cget 4 0x50 0x00" hangs I'll leave the BMC disabled for now in case that's important for further testing. If you need other tests run with the BMC enabled, I'll use a differen machine. Cheers, Rob.