Re: [Xen-devel] Linux 3.4 dom0 kernel error loading xen-acpi-processor: Input/output error

[Pasi Kärkkäinen <pasik@xxxxxx>]

On Fri, Mar 08, 2013 at 03:24:57PM -0500, Konrad Rzeszutek Wilk wrote:
> On Thu, Mar 07, 2013 at 09:48:08AM +0200, Pasi Kärkkäinen wrote:
> > On Wed, Mar 06, 2013 at 07:29:34PM -0500, Konrad Rzeszutek Wilk wrote:
> > > > > 
> > > > > Actually the correct path is: /sys/firmware/acpi/tables/DSDT
> > > > > So the acpi tables are there.
> > > > > 
> > > > > .. but the problem is there's no _PCT info in them.
> > > > > 
> > > > 
> > > > .. so on which hardware is xen-acpi-processor driver required? 
> > > > 
> > > > Is the actual problem that I don't have _PCT because it's not 
> > > > required/supported on my hw,
> > > > and thus I don't need the whole xen-acpi-processor driver? 
> > > > 
> > > > I checked the Xeon 5600 CPU, and also Ivy Bridge i7, and there's no 
> > > > _PCT on either one..
> > > 
> > > I always forget which of _P* are important. I think _PPC, _PSS and _PCD
> > > are the crucial ones. The _PCT is the thermal one - which I think are 
> > > usually
> > > found on laptops.
> > > 
> > 
> > I don't seem to have _PCT on my Ivy Bridge i7 laptop.. 
> > 
> > > In your case then .. lets go back to the start - the driver failed with 
> > > -EIO
> > > and it was v3.4.x kernel? Now that I've figured out the regression with 
> > > v3.9
> > > I can take a look at this.
> > > 
> > 
> > Ok.
> > 
> > So the problem for me with Linux 3.4.32 kernel is "modprobe 
> > xen-acpi-processor" fails:
> > initcall xen_acpi_processor_init+0x0/0x6b0 [xen_acpi_processor] returned 
> > with error code -5
> > 
> 
> Great :-( On my box (SandyBridge i3 2100, MS-7680) it installs just fine. 
> This is
> v3.4.22 with 
> 
> cat linux-build/.config|grep PROCESSOR
> CONFIG_ACPI_PROCESSOR=y
> CONFIG_ACPI_PROCESSOR_AGGREGATOR=m
> CONFIG_XEN_ACPI_PROCESSOR=m
> 

I'm using:

CONFIG_ACPI_PROCESSOR=y
CONFIG_ACPI_PROCESSOR_AGGREGATOR=m
CONFIG_XEN_ACPI_PROCESSOR=m


> 
> > The error deeper down in the ACPI internals is:
> > processor_perflib-0430 [00] processor_get_performa: ACPI-based processor 
> > performance control unavailable
> 
> I think looking at the code, that even on baremetal you would not have
> any P-states.
> 
> I am looking at the code, and the one thing that caught my eye is this 
> comment:
> 
> /*
>  * Do a quick check if the systems looks like it should use ACPI
>  * cpufreq. We look at a _PCT method being available, but don't
>  * do a whole lot of sanity checks.
>  */
> 
> And since your machine has no _PCT, it just bypasses it.
> 
> Is there a BIOS option for power saving? Perhaps its off? 
>

Hmm, good question, I'll have to check.. 


> > 
> > Function call path is this:
> > 
> > xen_acpi_processor_init()
> >     acpi_processor_register_performance(perf, i)                    <-- 
> > returns -EIO
> >             acpi_processor_get_performance_info(pr)                 <-- 
> > returns -ENODEV and prints the error to dmesg
> >                     acpi_get_handle(pr->handle, "_PCT", &handle);   
> >                             acpi_ns_get_node()                      <-- 
> > doesn't find _PCT
> > 
> >     goto err_out;                                                   <-- 
> > modprobe xen-acpi-processor fails
> > 
> > 
> > The CPU in question is:
> > Intel(R) Xeon(R) CPU L5640
> > 
> > ACPI DSDT.dsl is here:
> > http://pasik.reaktio.net/dell-r510-acpi-dsdt.dsl
> 
> Oh wait, this is not an laptop! It is some rack-server.
> 

Correct. It's a Dell R510 rack server.

-- Pasi


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel