Re: [PATCH 1/2] IPS driver: don't toggle CPU turbo on unsupported CPUs

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Thu, 23 Sep 2010 23:58:10 +0200
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:

> On Thursday, September 23, 2010, Jesse Barnes wrote:
> > On Thu, 23 Sep 2010 23:49:28 +0200
> > Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
> > 
> > > If the CPU doesn't support turbo, don't try to enable/disable it.
> > > 
> > > Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
> > > ---
> > >  drivers/platform/x86/intel_ips.c |   14 +++++++++-----
> > >  1 files changed, 9 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/drivers/platform/x86/intel_ips.c b/drivers/platform/x86/intel_ips.c
> > > index bfa9c72..71d04ef 100644
> > > --- a/drivers/platform/x86/intel_ips.c
> > > +++ b/drivers/platform/x86/intel_ips.c
> > > @@ -51,7 +51,6 @@
> > >   * TODO:
> > >   *   - handle CPU hotplug
> > >   *   - provide turbo enable/disable api
> > > - *   - make sure we can write turbo enable/disable reg based on MISC_EN
> > >   *
> > >   * Related documents:
> > >   *   - CDI 403777, 403778 - Auburndale EDS vol 1 & 2
> > > @@ -325,6 +324,7 @@ struct ips_driver {
> > >  	bool gpu_preferred;
> > >  	bool poll_turbo_status;
> > >  	bool second_cpu;
> > > +	bool turbo_toggle_allowed;
> > >  	struct ips_mcp_limits *limits;
> > >  
> > >  	/* Optional MCH interfaces for if i915 is in use */
> > > @@ -461,7 +461,8 @@ static void ips_enable_cpu_turbo(struct ips_driver *ips)
> > >  	if (ips->__cpu_turbo_on)
> > >  		return;
> > >  
> > > -	on_each_cpu(do_enable_cpu_turbo, ips, 1);
> > > +	if (ips->turbo_toggle_allowed)
> > > +		on_each_cpu(do_enable_cpu_turbo, ips, 1);
> > >  
> > >  	ips->__cpu_turbo_on = true;
> > >  }
> > > @@ -498,7 +499,8 @@ static void ips_disable_cpu_turbo(struct ips_driver *ips)
> > >  	if (!ips->__cpu_turbo_on)
> > >  		return;
> > >  
> > > -	on_each_cpu(do_disable_cpu_turbo, ips, 1);
> > > +	if (ips->turbo_toggle_allowed)
> > > +		on_each_cpu(do_disable_cpu_turbo, ips, 1);
> > >  
> > >  	ips->__cpu_turbo_on = false;
> > >  }
> > > @@ -1332,8 +1334,10 @@ static struct ips_mcp_limits *ips_detect_cpu(struct ips_driver *ips)
> > >  	 * turbo manually or we'll get an illegal MSR access, even though
> > >  	 * turbo will still be available.
> > >  	 */
> > > -	if (!(misc_en & IA32_MISC_TURBO_EN))
> > > -		; /* add turbo MSR write allowed flag if necessary */
> > > +	if (misc_en & IA32_MISC_TURBO_EN)
> > > +		ips->turbo_toggle_allowed = true;
> > > +	else
> > > +		ips->turbo_toggle_allowed = false;
> > >  
> > >  	if (strstr(boot_cpu_data.x86_model_id, "CPU       M"))
> > >  		limits = &ips_sv_limits;
> > 
> > Rafael and infernix, this patch should address the GPF in the IPS
> > driver (kernel bug 18742).
> > 
> > Matthew, since I forgot to add a link to the kernel bug in the log, can
> > you add it when you commit?
> > 
> > http://bugzilla.kernel.org/show_bug.cgi?id=18742
> 
> Can you drop the patch into the Bugzilla for completeness?
> 
> Or is it in patchwork?

Dunno about patchwork, but I just added it to the bug.

-- 
Jesse Barnes, Intel Open Source Technology Center