Re: [PATCH] powernow-k8: depend on acpi-processor for SMP systems

[Ed Sweetman]

Ed Sweetman wrote:
> Dave Jones wrote:
> > On Thu, May 17, 2007 at 02:13:42PM -0400, Len Brown wrote:
> >
> >  > > Index: linux/arch/i386/kernel/cpu/cpufreq/Kconfig
> >  > > ===================================================================
> >  > > --- linux.orig/arch/i386/kernel/cpu/cpufreq/Kconfig
> >  > > +++ linux/arch/i386/kernel/cpu/cpufreq/Kconfig
> >  > > @@ -81,6 +81,7 @@ config X86_POWERNOW_K7_ACPI
> >  > >  config X86_POWERNOW_K8
> >  > >      tristate "AMD Opteron/Athlon64 PowerNow!"
> >  > >      select CPU_FREQ_TABLE
> >  > > +    select ACPI_PROCESSOR if SMP
> >  > >      depends on EXPERIMENTAL
> >  > >      help
> >  > >        This adds the CPUFreq driver for mobile AMD 
> > Opteron/Athlon64 processors.
> >  >  > Unfortunately this patch will not actually enable 
> > ACPI_PROCESSOR in
> >  > the SMP=y ACPI=n case.  "select" doesn't work for targets that
> >  > have dependencies.
> >
> > I don't think we can fix this perfectly tbh, but the above at
> > least gets us close for the majority of users.
> >
> > Are there many x86-64 users that don't enable acpi ?
> >
> >     Dave
> >
> >   
> I've just always compiled acpi_processor in, it's only logical that if 
> you are using a power management feature, that you compile in the 
> power management interface, and if your stuff deals directly with the 
> cpu, you may want to compile the acpi_processor driver in.  The only 
> reason I knew to do that though, was because i go through each 
> option.  Someone else looking to just enable cpufreq, would skip the 
> sub-drivers of ACPI, and never know better. We dont suggest anywhere 
> in the cpufreq driver, we dont mention restrictions or limits of the 
> driver without acpi, and we certainly dont select it or make it 
> dependent (except silently and invisibly to the user).
> Every other cpufreq driver demands acpi.  In windows you have to have 
> acpi, the p states are called acpi p states everywhere.  The problem 
> here is that the author to the powernow_k8 driver found a way to get 
> some cpufreq functionality without acpi.
> So to make everyone happy, maybe we should have the silently 
> selected/deselected driver exposed to the user, as a sub-driver.
> ->  Powernow K8 / athlon64  cpufreq driver     y/m/n
> ------->    ACPI support      y/m/n

Here's a patch

--- ./linux-backup/arch/x86_64/kernel/cpufreq/Kconfig	2007-02-04 13:44:54.000000000 -0500
+++ ./linux-2.6.21-rc5-mm2/arch/x86_64/kernel/cpufreq/Kconfig	2007-05-17 17:37:24.000000000 -0400
@@ -10,7 +10,7 @@
 
 comment "CPUFreq processor drivers"
 
-config X86_POWERNOW_K8
+config  X86_POWERNOW_K8
 	tristate "AMD Opteron/Athlon64 PowerNow!"
 	select CPU_FREQ_TABLE
 	help
@@ -21,10 +21,10 @@
 	  If in doubt, say N.
 
 config X86_POWERNOW_K8_ACPI
-	bool
+	tristate "ACPI support"
 	depends on X86_POWERNOW_K8 && ACPI_PROCESSOR
 	depends on !(X86_POWERNOW_K8 = y && ACPI_PROCESSOR = m)
-	default y
+
 
 config X86_SPEEDSTEP_CENTRINO
 	tristate "Intel Enhanced SpeedStep (deprecated)"