| Message ID | 20201209153440.27643-1-daniel.lezcano@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [RFC,1/4] thermal/core: Emit a warning if the thermal zone is updated without ops | expand |
Hi Daniel, On 12/9/20 3:34 PM, Daniel Lezcano wrote: > 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> > --- > drivers/thermal/thermal_core.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > index dee40ff41177..afc02e7d1045 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", __FUNCTION__)) > return; > > update_temperature(tz); > With this RFC and the link that you gave me in previous thread, I see the motivation. I would change __FUNCTION__ into __func__, but other than that LGTM. Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Regards, Lukasz
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index dee40ff41177..afc02e7d1045 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", __FUNCTION__)) return; update_temperature(tz);
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> --- drivers/thermal/thermal_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) -- 2.17.1