diff mbox series

[1/5] thermal/core: Emit a warning if the thermal zone is updated without ops

Message ID 20201210121514.25760-1-daniel.lezcano@linaro.org
State Accepted
Commit 433178e75834dc35f1ae79b56ec2cf396f2c6f3c
Headers show
Series [1/5] thermal/core: Emit a warning if the thermal zone is updated without ops | expand

Commit Message

Daniel Lezcano Dec. 10, 2020, 12:15 p.m. UTC 
The actual code is silently ignoring a thermal zone update when a
driver is requesting it without a get_temp ops set.

That looks not correct, as the caller should not have called this
function if the thermal zone is unable to read the temperature.

That makes the code less robust as the check won't detect the driver
is inconsistently using the thermal API and that does not help to
improve the framework as these circumvolutions hide the problem at the
source.

In order to detect the situation when it happens, let's add a warning
when the update is requested without the get_temp() ops set.

Any warning emitted will have to be fixed at the source of the
problem: the caller must not call thermal_zone_device_update if there
is not get_temp callback set.

Cc: Thara Gopinath <thara.gopinath@linaro.org>
Cc: Amit Kucheria <amitk@kernel.org>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>

---
 drivers/thermal/thermal_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

-- 
2.17.1

Comments

Daniel Lezcano Dec. 17, 2020, 6:28 a.m. UTC | #1 
On 10/12/2020 13:15, Daniel Lezcano wrote:
> The acpi driver wants to do a netlink notification in case of a hot or

> critical trip point. Implement the corresponding ops to be used for

> the thermal zone and use them instead of the notify ops.

> 

> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>


Is there any comment on this patch ?

> ---

>  drivers/acpi/thermal.c | 30 ++++++++++++++----------------

>  1 file changed, 14 insertions(+), 16 deletions(-)

> 

> diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c

> index 12c0ece746f0..b5e4bc9e3282 100644

> --- a/drivers/acpi/thermal.c

> +++ b/drivers/acpi/thermal.c

> @@ -677,27 +677,24 @@ static int thermal_get_trend(struct thermal_zone_device *thermal,

>  	return 0;

>  }

>  

> -

> -static int thermal_notify(struct thermal_zone_device *thermal, int trip,

> -			   enum thermal_trip_type trip_type)

> +static void acpi_thermal_zone_device_hot(struct thermal_zone_device *thermal)

>  {

> -	u8 type = 0;

>  	struct acpi_thermal *tz = thermal->devdata;

>  

> -	if (trip_type == THERMAL_TRIP_CRITICAL)

> -		type = ACPI_THERMAL_NOTIFY_CRITICAL;

> -	else if (trip_type == THERMAL_TRIP_HOT)

> -		type = ACPI_THERMAL_NOTIFY_HOT;

> -	else

> -		return 0;

> -

>  	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,

> -					dev_name(&tz->device->dev), type, 1);

> +					dev_name(&tz->device->dev),

> +					ACPI_THERMAL_NOTIFY_HOT, 1);

> +}

>  

> -	if (trip_type == THERMAL_TRIP_CRITICAL && nocrt)

> -		return 1;

> +static void acpi_thermal_zone_device_critical(struct thermal_zone_device *thermal)

> +{

> +	struct acpi_thermal *tz = thermal->devdata;

>  

> -	return 0;

> +	acpi_bus_generate_netlink_event(tz->device->pnp.device_class,

> +					dev_name(&tz->device->dev),

> +					ACPI_THERMAL_NOTIFY_CRITICAL, 1);

> +

> +	thermal_zone_device_critical(thermal);

>  }

>  

>  static int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,

> @@ -812,7 +809,8 @@ static struct thermal_zone_device_ops acpi_thermal_zone_ops = {

>  	.get_trip_temp = thermal_get_trip_temp,

>  	.get_crit_temp = thermal_get_crit_temp,

>  	.get_trend = thermal_get_trend,

> -	.notify = thermal_notify,

> +	.hot = acpi_thermal_zone_device_hot,

> +	.critical = acpi_thermal_zone_device_critical,

>  };

>  

>  static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)

> 



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Srinivas Pandruvada Dec. 17, 2020, 11:38 a.m. UTC | #2 
On Thu, 2020-12-17 at 07:28 +0100, Daniel Lezcano wrote:
> On 10/12/2020 13:15, Daniel Lezcano wrote:

> > The acpi driver wants to do a netlink notification in case of a hot

> > or

> > critical trip point. Implement the corresponding ops to be used for

> > the thermal zone and use them instead of the notify ops.

> > 

> > Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

> 

> Is there any comment on this patch ?


Looks good to me.

Thanks,
Srinivas

> 

> > ---

> >  drivers/acpi/thermal.c | 30 ++++++++++++++----------------

> >  1 file changed, 14 insertions(+), 16 deletions(-)

> > 

> > diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c

> > index 12c0ece746f0..b5e4bc9e3282 100644

> > --- a/drivers/acpi/thermal.c

> > +++ b/drivers/acpi/thermal.c

> > @@ -677,27 +677,24 @@ static int thermal_get_trend(struct

> > thermal_zone_device *thermal,

> >         return 0;

> >  }

> >  

> > -

> > -static int thermal_notify(struct thermal_zone_device *thermal, int

> > trip,

> > -                          enum thermal_trip_type trip_type)

> > +static void acpi_thermal_zone_device_hot(struct

> > thermal_zone_device *thermal)

> >  {

> > -       u8 type = 0;

> >         struct acpi_thermal *tz = thermal->devdata;

> >  

> > -       if (trip_type == THERMAL_TRIP_CRITICAL)

> > -               type = ACPI_THERMAL_NOTIFY_CRITICAL;

> > -       else if (trip_type == THERMAL_TRIP_HOT)

> > -               type = ACPI_THERMAL_NOTIFY_HOT;

> > -       else

> > -               return 0;

> > -

> >         acpi_bus_generate_netlink_event(tz->device-

> > >pnp.device_class,

> > -                                       dev_name(&tz->device->dev),

> > type, 1);

> > +                                       dev_name(&tz->device->dev),

> > +                                       ACPI_THERMAL_NOTIFY_HOT,

> > 1);

> > +}

> >  

> > -       if (trip_type == THERMAL_TRIP_CRITICAL && nocrt)

> > -               return 1;

> > +static void acpi_thermal_zone_device_critical(struct

> > thermal_zone_device *thermal)

> > +{

> > +       struct acpi_thermal *tz = thermal->devdata;

> >  

> > -       return 0;

> > +       acpi_bus_generate_netlink_event(tz->device-

> > >pnp.device_class,

> > +                                       dev_name(&tz->device->dev),

> > +                                       ACPI_THERMAL_NOTIFY_CRITICA

> > L, 1);

> > +

> > +       thermal_zone_device_critical(thermal);

> >  }

> >  

> >  static int acpi_thermal_cooling_device_cb(struct

> > thermal_zone_device *thermal,

> > @@ -812,7 +809,8 @@ static struct thermal_zone_device_ops

> > acpi_thermal_zone_ops = {

> >         .get_trip_temp = thermal_get_trip_temp,

> >         .get_crit_temp = thermal_get_crit_temp,

> >         .get_trend = thermal_get_trend,

> > -       .notify = thermal_notify,

> > +       .hot = acpi_thermal_zone_device_hot,

> > +       .critical = acpi_thermal_zone_device_critical,

> >  };

> >  

> >  static int acpi_thermal_register_thermal_zone(struct acpi_thermal

> > *tz)

> > 

> 

>
Daniel Lezcano Dec. 17, 2020, 1:10 p.m. UTC | #3 
On 17/12/2020 12:38, Srinivas Pandruvada wrote:
> On Thu, 2020-12-17 at 07:28 +0100, Daniel Lezcano wrote:
>> On 10/12/2020 13:15, Daniel Lezcano wrote:
>>> The acpi driver wants to do a netlink notification in case of a hot
>>> or
>>> critical trip point. Implement the corresponding ops to be used for
>>> the thermal zone and use them instead of the notify ops.
>>>
>>> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
>>
>> Is there any comment on this patch ?
> 
> Looks good to me.

Thanks for reviewing
diff mbox series

Patch

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index dee40ff41177..e6771e5aeedb 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -548,7 +548,8 @@  void thermal_zone_device_update(struct thermal_zone_device *tz,
 	if (atomic_read(&in_suspend))
 		return;
 
-	if (!tz->ops->get_temp)
+	if (WARN_ONCE(!tz->ops->get_temp, "'%s' must not be called without "
+		      "'get_temp' ops set\n", __func__))
 		return;
 
 	update_temperature(tz);