Re: [stable] [PATCH] Make acpi-cpufreq more robust against BIOS freq changes behind our back

[Chris Wright <chrisw@sous-sol.org>]

* Anthony L. Awtrey (tony@awtrey.com) wrote:
> On 05/21/2008 09:08 AM, Thomas Renninger wrote:
> > commit e56a727b023d40d1adf660168883f30f2e6abe0a
> > Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
> > Date:   Mon Apr 28 15:13:43 2008 -0400
> > 
> >     [CPUFREQ] Make acpi-cpufreq more robust against BIOS freq changes behind our back.
> >     
> >     We checked the hardware freq with OS cached freq value in get_cur_freqon_cpu().
> >     
> >     Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
> >     Signed-off-by: Thomas Renninger <trenn@suse.de>
> >     Signed-off-by: Dave Jones <davej@redhat.com>
> > 
> > diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
> > index e2d870d..8db8f73 100644
> > --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
> > +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
> > @@ -339,6 +339,7 @@ static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
> >  {
> >  	struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
> >  	unsigned int freq;
> > +	unsigned int cached_freq;
> >  
> >  	dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
> >  
> > @@ -347,7 +348,16 @@ static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
> >  		return 0;
> >  	}
> >  
> > +	cached_freq = data->freq_table[data->acpi_data->state].frequency;
> >  	freq = extract_freq(get_cur_val(&cpumask_of_cpu(cpu)), data);
                                       -^-
This does not apply cleanly to 2.6.25.4 (doesn't have commit: fc0e4748).

> I worked! This patch applied to 2.6.25.4 fixed the CPU stepping problem 
> on the Panasonic CF-18 (Pentium M) I was having.

I suppose you manually applied the patch?

Anyway, I backported and will add to -stable, please holler if this is
wrong.

thanks,
-chris