Messages in this thread | | | Date | Thu, 09 Oct 2014 18:47:30 +0200 | From | Lukasz Majewski <> | Subject | Re: [PATCH 3/3] thermal: core: fix: Check return code of the ->get_max_state() callback |
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Hi Zhang,
> On Fri, 2014-10-03 at 12:40 +0200, Lukasz Majewski wrote: > > Hi Eduardo, Rui, > > > > > On Wed, Sep 24, 2014 at 10:27:12AM +0200, Lukasz Majewski wrote: > > > > Without this check it was possible to execute cooling device > > > > binding code even when wrong max cooling state was read. > > > > > > > > Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> > > > > > > Acked-by: Eduardo Valentin <edubezval@gmail.com> > > > > > > Rui, are you taking these patches? Do you prefer me to collect > > > them? > > > > I'd like to ask you NOT to apply those patches. > > > > In short: It will cause regression on all non Exynos boards. > > > > Explanation: > > > > Up till now the cpu_cooling device was bind even when the > > get_max_state() returned -EINVAL and everything worked after late > > cpufreq policy initialization. > > > > However, during this time window the thermal driver is not properly > > configured. > > > > Applying PATCH2/3 and PATCH3/3 would cause bind error without any > > further occasion for re-bind. As a result THERAL will not be present > > on the target system. > > > > It works on the Exynos boards, since at the report_trigger() > > function, when first trip point is reached, it is checked if > > cpu_cooling device is bind. If it is not (due to "fixes" at > > PATCH2/3 and PATCH3/3) it is rebind then. > > > > Due to above, I think that it would be best to leave things as they > > are now and prepare proper fix as suggested by Eduardo. > > > Agreed. Can anyone please propose such a patch?
I can propose myself as a volunteer for this. Unfortunately, I won't be able to provide any code earlier than in two weeks time.
> > thanks, > rui > > > > > > Cheers > > > > > > Eduardo > > > > > > > --- > > > > drivers/thermal/thermal_core.c | 6 ++++-- > > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/drivers/thermal/thermal_core.c > > > > b/drivers/thermal/thermal_core.c index 747618a..8a4dc35 100644 > > > > --- a/drivers/thermal/thermal_core.c > > > > +++ b/drivers/thermal/thermal_core.c > > > > @@ -928,7 +928,7 @@ int thermal_zone_bind_cooling_device(struct > > > > thermal_zone_device *tz, struct thermal_zone_device *pos1; > > > > struct thermal_cooling_device *pos2; > > > > unsigned long max_state = 0; > > > > - int result; > > > > + int result, ret; > > > > > > > > if (trip >= tz->trips || (trip < 0 && trip != > > > > THERMAL_TRIPS_NONE)) return -EINVAL; > > > > @@ -945,7 +945,9 @@ int thermal_zone_bind_cooling_device(struct > > > > thermal_zone_device *tz, if (tz != pos1 || cdev != pos2) > > > > return -EINVAL; > > > > > > > > - cdev->ops->get_max_state(cdev, &max_state); > > > > + ret = cdev->ops->get_max_state(cdev, &max_state); > > > > + if (ret) > > > > + return ret; > > > > > > > > /* lower default 0, upper default max_state */ > > > > lower = lower == THERMAL_NO_LIMIT ? 0 : lower; > > > > -- > > > > 2.0.0.rc2 > > > > > > > > > > >
-- Best regards,
Lukasz Majewski
Samsung R&D Institute Poland (SRPOL) | Linux Platform Group
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