Messages in this thread Patch in this message | | | Subject | Re: [PATCH 1/3] thermal: core: Add indication for userspace usage | From | Kai-Heng Feng <> | Date | Mon, 30 Nov 2020 16:23:59 +0800 |
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> On Nov 30, 2020, at 15:57, Daniel Lezcano <daniel.lezcano@linaro.org> wrote: > > > [Added Srinivas] > > On 28/11/2020 18:54, Kai-Heng Feng wrote: >> We are seeing thermal shutdown on Intel based mobile workstations, the >> shutdown happens during the first trip handle in >> thermal_zone_device_register(): >> kernel: thermal thermal_zone15: critical temperature reached (101 C), shutting down >> >> However, we shouldn't do a thermal shutdown here, since >> 1) We may want to use a dedicated daemon, Intel's thermald in this case, >> to handle thermal shutdown. >> >> 2) For ACPI based system, _CRT doesn't mean shutdown unless it's inside >> ThermalZone. ACPI Spec, 11.4.4 _CRT (Critical Temperature): >> "... If this object it present under a device, the device’s driver >> evaluates this object to determine the device’s critical cooling >> temperature trip point. This value may then be used by the device’s >> driver to program an internal device temperature sensor trip point." >> >> So a "critical trip" here merely means we should take a more aggressive >> cooling method. > > Well, actually it is stated before: > > "This object, when defined under a thermal zone, returns the critical > temperature at which OSPM must shutdown the system".
This means specifically for the ACPI ThermalZone in AML, e.g.:
ThermalZone (TZ0) { .... Method(_CRT) { ... } } // end of TZ0
However the device is not under any ACPI ThermalZone.
> > That is what does the thermal subsystem, no ? > >> So add an indication to let thermal core know it should leave thermal >> device to userspace to handle. > > You may want to check the 'HOT' trip point and then use the notification > mechanism to get notified in userspace and take action from there (eg. > offline some CPUs).
For this particular issue we are facing, the thermal shutdown happens in thermal_zone_device_register() and userspace isn't up yet.
Kai-Heng
> >> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> >> --- >> drivers/thermal/thermal_core.c | 3 +++ >> include/linux/thermal.h | 2 ++ >> 2 files changed, 5 insertions(+) >> >> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c >> index c6d74bc1c90b..6561e3767529 100644 >> --- a/drivers/thermal/thermal_core.c >> +++ b/drivers/thermal/thermal_core.c >> @@ -1477,6 +1477,9 @@ thermal_zone_device_register(const char *type, int trips, int mask, >> goto unregister; >> } >> >> + if (tz->tzp && tz->tzp->userspace) >> + thermal_zone_device_disable(tz); >> + >> mutex_lock(&thermal_list_lock); >> list_add_tail(&tz->node, &thermal_tz_list); >> mutex_unlock(&thermal_list_lock); >> diff --git a/include/linux/thermal.h b/include/linux/thermal.h >> index d07ea27e72a9..e8e8fac78fc8 100644 >> --- a/include/linux/thermal.h >> +++ b/include/linux/thermal.h >> @@ -247,6 +247,8 @@ struct thermal_zone_params { >> */ >> bool no_hwmon; >> >> + bool userspace; >> + >> int num_tbps; /* Number of tbp entries */ >> struct thermal_bind_params *tbp; >> >> > > > -- > <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs > > Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | > <http://twitter.com/#!/linaroorg> Twitter | > <http://www.linaro.org/linaro-blog/> Blog
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