Re: [PATCH 1/1] thermal: fix cpu_cooling max_level behavior

From: Zhang Rui
Date: Wed Jan 01 2014 - 23:02:49 EST


On Fri, 2013-12-06 at 09:52 -0400, Eduardo Valentin wrote:
> On 13-11-2013 14:11, Eduardo Valentin wrote:
> > As per Documentation/thermal/sysfs-api.txt, max_level
> > is an index, not a counter. Thus, in case a CPU has
> > 3 valid frequencies, max_level is expected to be 2, for instance.
> >
> > The current code makes max_level == number of valid frequencies,
> > which is bogus. This patch fix the cpu_cooling device by
> > ranging max_level properly.
> >
good catch.
> > Reported-by: Carlos Hernandez <ceh@xxxxxx>
> > Signed-off-by: Eduardo Valentin <eduardo.valentin@xxxxxx>
>
> Rui,
>
> Can you please consider pushing this fix?
>
applied.

> > ---
> > drivers/thermal/cpu_cooling.c | 6 ++++--
> > 1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
> > index d179028..d0f8f8b5 100644
> > --- a/drivers/thermal/cpu_cooling.c
> > +++ b/drivers/thermal/cpu_cooling.c
> > @@ -173,6 +173,8 @@ static int get_property(unsigned int cpu, unsigned long input,
> > freq = table[i].frequency;
> > max_level++;
> > }
> > + /* max_level is an index, not a counter */
> > + max_level--;
> >
I think we should check the max_level first, like the patch I attached
below.

thanks,
rui