Hi Hank,
Thanks for the reply. The IBM server that we have is an x3850
X5 with Intel processors, so I do not think it is the POWER
architecture that you mentioned.
From my understanding, the BMC and devices on the SMBus should
be able to communicate in AUX power (power to main CPU is off,
OS is not running). So, from the IMM port, the BMC should still
be able to communicate via IPMI while the main power is off.
I've tried with both the power off (AUX) and power on (OS up and
running).
I've heard that our device in the PCI slot should be able to
communicate with the BMC in AUX power mode, so I think it should
be available to the BMC. The main issue I have is how to
communicate with the device from outside the server. Hence,
I've been looking into IPMI and the IMM management port using
IPMI.
Do you happen to know how I might bridge IPMI to SMBus or I2C to
get to the PCI device? I noticed that there is a "raw" command
in IPMI. Also, there appears to be a "Send Message" and "Get
Message" command that is supposed to bridge between channels.
Not sure if these avenues will help me, though...
You are right, in that I need to make sure the IBM server is
even allowing the communication between the BMC and the device
in the PCI slot. From what I've seen so far, it looks like it
may not, but then again it could just be that I don't know how
to "bridge" from the outside protocol (IPMI) to the internal
bus.
Thanks for the help,
Steve
Date: Tue, 3 Feb 2015 06:04:34 -0500
Subject: Re: [Ipmitool-devel] How do I find information on a
PCI device using ipmitool over the network?
From:
h...@jblade.com
To:
smrca...@outlook.com
CC:
ipmitool-devel@lists.sourceforge.net
What model IBM server ? If it is the POWER
architecture?
There might not be any electrical connection
between the PCI connector pins that the SMBus
and the BMC. Neither the PCI spec or the IPMI
spec require that the PCI Bus's SMBus is
connected to the BMC. It is up to the server
vendor if they what to add value by connecting
the PCI SMBus to to the BMC.
On the PCI card the SMBus is also optional. It is
possible to have a motherboard that connects the
BMC to the PCI slosts but the PCI cards do not
implement the SMBus.
To debug this you might try this:
1) Examine the server vendor documentation and see if
the PCI SMBus has an electrical path to the BMC. Thr
SMBus might only be routed to a CPU that runs the BIOS
or what ever IBM uses for that.
2) Find out if the PCI card implements the SMBus
3) Ensure that the SMBus is operating. The PCI Bus can be
powered off but the SMBus can be powered on and still
operate. You did not mention if the main CPU is powered
on. If it is not there would be a IPMI OEM command to
power on/off the PCI bus or power is supplied to the PCI
and SMBus when the CPUs are turned on by the BMC.
Hank
