Re: 2.6.27: 0 MHz CPU and wrong system time on AMD Geode system

Re: 2.6.27: 0 MHz CPU and wrong system time on AMD Geode system

[Antipov Dmitry]

Jordan Crouse wrote:

> Could you try a 2.6.26 kernel? That will confirm that this is a new
> addition to 2.6.27.

Both 2.6.26 and 2.6.26.6 looks good (with CONFIG_GEODE_MFGPT_TIMER=y).

Dmitry

Re: 2.6.27: 0 MHz CPU and wrong system time on AMD Geode system

[Alok Kataria]

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On Thu, Oct 16, 2008 at 9:48 PM, Antipov Dmitry <dmantipov@yandex.ru> wrote:
> Jordan Crouse wrote:
>
>> Could you try a 2.6.26 kernel? That will confirm that this is a new
>> addition to 2.6.27.
>
> Both 2.6.26 and 2.6.26.6 looks good (with CONFIG_GEODE_MFGPT_TIMER=y).

Can you try the attached debug patch, it puts a printk message and
will let us know what exaclty is failing during the calibration
process.
There were some major changes in the 2.6.27 cycle related to tsc calibration.
Apart from the unification for 32 and 64bit, some checks were added in
the code to make the calibration process more robust, maybe this
specific machine is more prone to SMI's than other, as a result the
checks are a little to harsh for this one.

Along with the dmesg with this patch, could you also let us know how
much is the frequency that the (2.6.26) kernel calibrates and what the
actual freuqency is on that box ?

Thanks,
Alok
>
> Dmitry
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[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
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Index: linux-2.6/arch/x86/kernel/tsc.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/tsc.c	2008-10-17 14:56:23.000000000 -0700
+++ linux-2.6/arch/x86/kernel/tsc.c	2008-10-17 15:01:38.000000000 -0700
@@ -163,6 +163,8 @@
 		pitcnt++;
 	}
 
+	printk("DEBUG: pitcnt %d, tscmin %lu, tscmax %lu\n",
+				pitcnt, tscmin, tscmax);
 	/*
 	 * Sanity checks:
 	 *

Re: 2.6.27: 0 MHz CPU and wrong system time on AMD Geode system

[Lennart Sorensen]

On Fri, Oct 17, 2008 at 03:17:39PM -0700, Alok Kataria wrote:
> Can you try the attached debug patch, it puts a printk message and
> will let us know what exaclty is failing during the calibration
> process.
> There were some major changes in the 2.6.27 cycle related to tsc calibration.
> Apart from the unification for 32 and 64bit, some checks were added in
> the code to make the calibration process more robust, maybe this
> specific machine is more prone to SMI's than other, as a result the
> checks are a little to harsh for this one.

I recently had to disable the timer generating an SMI on our platform,
because it would cause FIFO overflows on serial ports and other
infrequent problems.  SMM/SMI is just a pain in the rear.

I haven't tried 2.6.27 yet, but have not had issues with 2.6.26 so far
(other than it seemingly breaking the SC1200's ide controller with
certain compact flash cards which I am still trying to track down, but
that isn't a Geode LX problem, that's a Geode SC1200 problem).

-- 
Len Sorensen

Re: 2.6.27: 0 MHz CPU and wrong system time on AMD Geode system

[Jordan Crouse]

On 17/10/08 15:17 -0700, Alok Kataria wrote:
> On Thu, Oct 16, 2008 at 9:48 PM, Antipov Dmitry <dmantipov@yandex.ru> wrote:
> > Jordan Crouse wrote:
> >
> >> Could you try a 2.6.26 kernel? That will confirm that this is a new
> >> addition to 2.6.27.
> >
> > Both 2.6.26 and 2.6.26.6 looks good (with CONFIG_GEODE_MFGPT_TIMER=y).
> 
> Can you try the attached debug patch, it puts a printk message and
> will let us know what exaclty is failing during the calibration
> process.
> There were some major changes in the 2.6.27 cycle related to tsc calibration.
> Apart from the unification for 32 and 64bit, some checks were added in
> the code to make the calibration process more robust, maybe this
> specific machine is more prone to SMI's than other, as a result the
> checks are a little to harsh for this one.
> 
> Along with the dmesg with this patch, could you also let us know how
> much is the frequency that the (2.6.26) kernel calibrates and what the
> actual freuqency is on that box ?

I just booted with 2.6.27.1 with high res timers on, and I can't recreate
on a generic Geode box.  The only difference is that my system doesn't
have any MFGPT timers available, but that shouldn't matter if you have
CONFIG_GEODE_MFGPT_TIMER turned off.

Jordan

-- 
Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.

Re: 2.6.27: 0 MHz CPU and wrong system time on AMD Geode system

[Jordan Crouse]

On 16/10/08 15:31 +0400, Dmitry Antipov wrote:
> Jordan Crouse wrote:
> 
> > Hmmm - this is an interesting regression.  Please remove
> > CONFIG_GEODE_MFGPT_TIMER=y from your 2.6.27 kernel and see if the
> > problem goes away. 
> 
> Unfortunately it doesn't help.

Okay - that has been the reason for breakage in the past, so you can't
blame me for trying. :)

Could you try a 2.6.26 kernel?  That will confirm that this is a new
addition to 2.6.27.

> > I have been running 2.6.26.5 on my system with no problems, but I'm
>  > embarrassed to admit that I haven't run anything newer in a while.
> 
> What system do you have?

I have a wide variety of platforms available.  The good (or bad?) thing
about Geode is that the hardware generally looks the same, give or take
a superIO here and there.  If this is really a problem with the PIT or
TSC, then it should break easily.

Jordan

-- 
Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.

Re: 2.6.27: 0 MHz CPU and wrong system time on AMD Geode system

[Dmitry Antipov]

Jordan Crouse wrote:

> Hmmm - this is an interesting regression.  Please remove
> CONFIG_GEODE_MFGPT_TIMER=y from your 2.6.27 kernel and see if the
> problem goes away. 

Unfortunately it doesn't help.

> I have been running 2.6.26.5 on my system with no problems, but I'm
 > embarrassed to admit that I haven't run anything newer in a while.

What system do you have?

Dmitry

Re: 2.6.27: 0 MHz CPU and wrong system time on AMD Geode system

[Jordan Crouse]

On 15/10/08 10:39 +0400, Antipov Dmitry wrote:
> After updating the kernel to 2.6.27 from 2.6.25.4, my system time goes wrong and
> CPU becomes 0 MHz (as shown by /proc/cpuinfo), probably due to these issues:
> 
> TSC: Unable to calibrate against PIT
> TSC: No reference (HPET/PMTIMER) available
> Marking TSC unstable due to could not calculate TSC khz
> 
> The hardware is http://www.fit-pc.com/new/fit-pc-1-0-specifications.html,
> and the base system is Fedora 9.
> 
> More details: 2.6.25.4 .config: http://78.153.153.8/tmp/config-2.6.25.4.txt
>               2.6.25.4 boot messages: http://78.153.153.8/tmp/boot-2.6.25.4.txt
>               2.6.27 .config: http://78.153.153.8/tmp/config-2.6.27.txt
>               2.6.27 boot messages: http://78.153.153.8/tmp/boot-2.6.27.txt

Hmmm - this is an interesting regression.  Please remove
CONFIG_GEODE_MFGPT_TIMER=y from your 2.6.27 kernel and see if the
problem goes away.  I have been running 2.6.26.5 on my system with no
problems, but I'm embarrassed to admit that I haven't run anything
newer in a while.  

Jordan
-- 
Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.

2.6.27: 0 MHz CPU and wrong system time on AMD Geode system

[Antipov Dmitry]

After updating the kernel to 2.6.27 from 2.6.25.4, my system time goes wrong and
CPU becomes 0 MHz (as shown by /proc/cpuinfo), probably due to these issues:

TSC: Unable to calibrate against PIT
TSC: No reference (HPET/PMTIMER) available
Marking TSC unstable due to could not calculate TSC khz

The hardware is http://www.fit-pc.com/new/fit-pc-1-0-specifications.html,
and the base system is Fedora 9.

More details: 2.6.25.4 .config: http://78.153.153.8/tmp/config-2.6.25.4.txt
              2.6.25.4 boot messages: http://78.153.153.8/tmp/boot-2.6.25.4.txt
              2.6.27 .config: http://78.153.153.8/tmp/config-2.6.27.txt
              2.6.27 boot messages: http://78.153.153.8/tmp/boot-2.6.27.txt

Dmitry