Re: ipmi_si fails to get BMC ID

[Corey Minyard]

I'm removing Greg and Arnd from the email, I don't think this requires 
their participation.



On 02/13/2018 08:44 PM, Chris Chiu wrote:
> On Fri, Feb 9, 2018 at 9:34 PM, Corey Minyard <minyard@xxxxxxx> wrote:
> > On 02/08/2018 09:09 PM, Chris Chiu wrote:
> > > On Thu, Feb 8, 2018 at 11:53 PM, Corey Minyard <minyard@xxxxxxx> wrote:
> > > > On 02/07/2018 09:01 PM, Chris Chiu wrote:
> > > > > Hi,
> > > > >        We are working with a new desktop Acer Veriton Z4640G and get
> > > > > stumbled on failing to enter S3 suspend with kernel version 4.14 even
> > > > > the latest 4.15+. Here's the kernel log
> > > > > https://gist.github.com/mschiu77/76888f1fd4eb56aa8959d76759a912bb.
> > > >
> > > > This is a little strange, nobody had reported this before.  Can you
> > > > reproduce this
> > > > at will, or was it a one-time thing?
> > > It can be reproduced on each reboot.
> > > > Does the IPMI driver always take this long to issue that error, even if
> > > > you
> > > > are not
> > > > entering sleep state?
> > > Yep, it will always print "ipmi_si 0000:02:00.3: There appears to be
> > > no BMC at this
> > > location" few minutes after boot.
> > >
> > > > And it started with 4.14, and didn't occur before then, right?
> > > I haven't try pre-4.14 kernel. Will do that and update here.
> >
> > Ah.  It's probably still worth trying, but I doubt it will make any
> > difference.
> >
> > Are you sure there is actually an IPMI BMC installed in this system?  It
> > might
> > be a plug-in card that is not installed, but the interface still appears on
> > the
> > PCI bus.  So there is enough hardware to go part-way through the motions
> > of being an IPMI interface, but not enough to actually work.
> >
> > If there is a BMC there, do you know the register layout?  The IPMI spec has
> > an algorithm to go through to discover some of the parameters, and the
> > driver follows it, but IMHO it's not really very good.  I'll need to know
> > the
> > size of the registers, and the spacing between the registers.
> >
> > -corey
> Sorry for late response because it's close to Chinese New Year.
> I can get the IPMI working with the driver here on Windows.
> https://www.drivermax.com/Realtek-Virtual-IPMI-Realtek-PCI-VEN-10EC-DEV-816C-1_0_0718_2013-2013-07-18-509795-driver.htm
> Then you will see the device (hightlighted) on the control panel as follows
> https://pasteboard.co/H7xm3fJ.png

Hmm, Windows has a built-in IPMI driver. I wonder why the aren't using 
that.
And I don't know what "Virtual IPMI" means.

> I don't know how to get the register layout you need. I can only take a
> picture of the content of the PCI resources.
> https://pasteboard.co/H7xnhz0.png
>
> The contents of BAR1, BAR3, BAR5 are all 0xff. Can you point me out
> where the useful information might be and I can try to dump FYI.

This whole thing sounds like they have created a non-standard IPMI interface
and put it on the PCI bus like a standard one. Unless we can get 
documentation
for this, there's not much I can do but blacklist it.

Do you have any ties with Realtek? I can't find anything on their web 
site related
to IPMI.

-corey

> Chris
>
> > > > There's a bug in the PCI utils database, I submitted a report a while
> > > > ago.
> > > > This is
> > > > a KCS, not a SMIC interface.
> > > >
> > > > It looks like the driver is trying to detect that there is a device out
> > > > there and
> > > > there is something that kind of works, but doesn't work completely. The
> > > > interface
> > > > specific code was all split out into separate files in 4.14.  It is
> > > > possible
> > > > the
> > > > detection code got messed up in the process.  Nothing jumps out looking
> > > > at
> > > > the code differences, and I know it works on some PCI machines.
> > > >
> > > > Assuming this is reproducible, can you send the the output of a pre-4.14
> > > > kernel?  If that doesn't make it obvious I may have to have access to the
> > > > machine itself.
> > > >
> > > > -corey
> > > It's an All-in-One machine so I think it would be difficult for
> > > shipment. I'll see what
> > > I can do. Thanks for help.
> > >
> > > Chris
> > >
> > > > >        As you see, it is due to "ipmi_probe+0x430/0x430 [ipmi_si]". After
> > > > > the message "ipmi_si 0000:02:00.3: There appears to be no BMC at this
> > > > > location" shows up, then it can really go to suspend w/o problem.
> > > > > Although it took around 3 mins. The IPMI device is probed from PCI and
> > > > > here's the output of lspci
> > > > > https://gist.github.com/mschiu77/33f0372be41670d8a69c97e64f833087. The
> > > > > IPMI device is "02:00.3 IPMI SMIC interface [0c07]". We get stuck here
> > > > > because we don't really know why it took so long in try_get_dev_id() /
> > > > > ipmi_si_intf.c. Any suggestion about this to help us moving forward?
> > > > > Thanks
> > > > >
> > > > >
> > > > > Chris