Linux IPMI subsystem hang

[Daniel Kahn Gillmor]

Hi Linux kernel folks (Corey is explicitly listed here because of being
the only contact i could find in IPMI.txt)--

I am working with a Lenovo ThinkCentre M78, model 4865-A14, and it seems
to have trouble with the IPMI subsystem.

udev seems to hang for about 3 minutes at startup, ultimately failing
with the following messages:

udevd[416]: worker [495] unexpectedly returned with status 0x0100
udevd[416]: worker [495] failed while handling '/devices/pci0000:00/0000:00:15.2/0000:03:00.3'

This hang happens whether i'm running linux kernel 3.2 or 3.8, using
either x86 or x86_64 kernels.

If i blacklist the following modules via /etc/modprobe.d/blacklist.conf,
then there is no hang on startup:

 blacklist ipmi_si
 blacklist ipmi_msghandler

The device in question appears this way to lspci:

03:00.3 IPMI SMIC interface [0c07]: Realtek Semiconductor Co., Ltd. Device [10ec:816c] (rev 01) (prog-if 01)
	Subsystem: Lenovo Device [17aa:3089]
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Latency: 0, Cache Line Size: 64 bytes
	Interrupt: pin D routed to IRQ 17
	Region 0: I/O ports at e000 [size=256]
	Region 2: Memory at fea10000 (64-bit, non-prefetchable) [size=256]
	Region 4: Memory at fea00000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: ipmi_si

This machine is a workstation, and i would be surprised if it actually
has a full-blown IPMI subsystem.  I can find no mention of IPMI in the
BIOS, or in lenovo's hardware maintenance manual [0] or user guide [1]
for this model.

So i suspect that this device is being mistaken for an IPMI device, or
that it is actually a broken/malformed IPMI device that shouldn't be
initialized.  Either that, or the IPMI module itself is doing something
wrong.

Can i do anything to help resolve this problem so that the machine boots
without delay and the ipmi subsystem doesn't get hung on this device?
Is there debugging output i can provide that would be useful, or any
other test you'd like me to run?

I'd be happy to report any requested details.  Also, if you want to
redirect me to a better forum for resolving this problem that would be
appreciated.

I am not subscribed to LKML, so please CC me on any replies.

Regards,

        --dkg

[0] http://download.lenovo.com/ibmdl/pub/pc/pccbbs/thinkcentre_pdf/m78_hmm.pdf
[1] http://download.lenovo.com/ibmdl/pub/pc/pccbbs/thinkcentre_pdf/m78_sff_ug_en.pdf

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