Re: 2.6.27.7 built for Geode: Clock drift

[Jordan Crouse <jordan@cosmicpenguin.net>]

Harald Dunkel wrote:
> Hi folks,
> 
> If I build a kernel for AMD Geode, then I see a clock drift of appr.
> 30 min. to 1 hour per day. If I build the same kernel for i486, then
> the clock drift is gone. Running ntp makes no difference.
> 
> Hardware is a Linutop PC. /proc/cpuinfo says
> 
> processor       : 0
> vendor_id       : AuthenticAMD
> cpu family      : 5
> model           : 10
> model name      : Geode(TM) Integrated Processor by AMD PCS
> stepping        : 2
> cpu MHz         : 0.000
> cache size      : 128 KB
> fdiv_bug        : no
> hlt_bug         : no
> f00f_bug        : no
> coma_bug        : no
> fpu             : yes
> fpu_exception   : yes
> cpuid level     : 1
> wp              : yes
> flags           : fpu de pse tsc msr cx8 sep pge cmov clflush mmx mmxext 3dnowext 3dnow
> bogomips        : 429.05
> clflush size    : 32
> power management:
> 
> BTW, the CPU is running with 500 MHz (AFAIK). 0.000 MHz is surely not
> correct. /proc/cpuinfo reports the same for both kernels.

Hmm - we've heard reports of this before, but nothing came of it.  I 
would be interested in a chance to debug it this time.

Please try turning off CONFIG_GEODE_MFGPT_TIMER=y and try again.  Also, 
try something in the 2.6.28 family to rule out fixes in the timer subsystem.

Thanks,
Jordan