> -----Original Message----- > From: Eduardo Valentin [mailto:edubezval@xxxxxxxxx] > Sent: Tuesday, March 24, 2015 11:00 PM > To: Zhang, Rui > Cc: linux-pm@xxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 1/3] Thermal: initialize thermal zone device correctly > Importance: High > > Rui, > > A couple of comments. > > On Tue, Mar 24, 2015 at 01:21:28PM +0800, Zhang Rui wrote: > > After thermal zone device registered, as we have not read any > > temperature before, thus tz->temperature should not be 0, which > > actually means 0C, and thermal trend is not available. > > In this case, we need specially handling for the first > > thermal_zone_device_update(). > > > > Both thermal core framework and step_wise governor is enhanced to handle > this. > > > > CC: <stable@xxxxxxxxxxxxxxx> #3.18+ > > Tested-by: Manuel Krause <manuelkrause@xxxxxxxxxxxx> > > Tested-by: szegad <szegadlo@xxxxxxxxxxxxxx> > > Tested-by: prash <prash.n.rao@xxxxxxxxx> > > Tested-by: amish <ammdispose-arch@xxxxxxxxx> > > Tested-by: Matthias <morpheusxyz123@xxxxxxxx> > > Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> > > --- > > drivers/thermal/step_wise.c | 15 +++++++++++++-- > > drivers/thermal/thermal_core.c | 19 +++++++++++++++++-- > > drivers/thermal/thermal_core.h | 1 + > > include/linux/thermal.h | 3 +++ > > 4 files changed, 34 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.c > > Should this patch also include changes in other governors ? > No, I've checked the code, step_wise/bang_bang/user_space governor does not have this problem. > > index 5a0f12d..c2bb37c 100644 > > --- a/drivers/thermal/step_wise.c > > +++ b/drivers/thermal/step_wise.c > > @@ -63,6 +63,16 @@ static unsigned long get_target_state(struct > thermal_instance *instance, > > next_target = instance->target; > > dev_dbg(&cdev->device, "cur_state=%ld\n", cur_state); > > > > + if (!instance->initialized) { > > + if (throttle) { > > + next_target = (cur_state + 1) >= instance->upper ? > > + instance->upper : > > + ((cur_state + 1) < instance->lower ? > > + instance->lower : (cur_state + 1)); > > Why it makes sense to change the next state if a instance is uninitialized? > For thermal safety reason, I prefer to use a higher cooling state because the system is overheating with current cooling state I even used to think about using instance->upper directly, but in this case, cooling devices like processors are put into the lowest frequency, and processors on ACPI based platform are put into lowest t-state, which is overkill. > > + } else > > + next_target = THERMAL_NO_TARGET; > > + } > > + > > switch (trend) { > > case THERMAL_TREND_RAISING: > > if (throttle) { > > @@ -149,7 +159,8 @@ static void thermal_zone_trip_update(struct > thermal_zone_device *tz, int trip) > > dev_dbg(&instance->cdev->device, "old_target=%d, > target=%d\n", > > old_target, (int)instance->target); > > > > - if (old_target == instance->target) > > + if (instance->initialized && > > + old_target == instance->target) > > continue; > > > > /* Activate a passive thermal instance */ @@ -161,7 +172,7 > @@ > > static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip) > > instance->target == THERMAL_NO_TARGET) > > update_passive_instance(tz, trip_type, -1); > > > > - > > + instance->initialized = true; > > instance->cdev->updated = false; /* cdev needs update */ > > } > > > > diff --git a/drivers/thermal/thermal_core.c > > b/drivers/thermal/thermal_core.c index 174d3bc..9d6f71b 100644 > > --- a/drivers/thermal/thermal_core.c > > +++ b/drivers/thermal/thermal_core.c > > @@ -469,8 +469,22 @@ static void update_temperature(struct > thermal_zone_device *tz) > > mutex_unlock(&tz->lock); > > > > trace_thermal_temperature(tz); > > - dev_dbg(&tz->device, "last_temperature=%d, > current_temperature=%d\n", > > - tz->last_temperature, tz->temperature); > > + if (tz->last_temperature == THERMAL_TEMP_INVALID) > > + dev_dbg(&tz->device, "last_temperature N/A, > current_temperature=%d\n", > > + tz->temperature); > > + else > > + dev_dbg(&tz->device, "last_temperature=%d, > current_temperature=%d\n", > > + tz->last_temperature, tz->temperature); > > Should we also teach the tracing facility about THERMAL_TEMP_INVALID? > Hmm, I don't quite understand your question. Thanks, rui > > +} > > + > > +static void thermal_zone_device_reset(struct thermal_zone_device *tz) > > +{ > > + struct thermal_instance *pos; > > + > > + tz->temperature = THERMAL_TEMP_INVALID; > > + tz->passive = 0; > > + list_for_each_entry(pos, &tz->thermal_instances, tz_node) > > + pos->initialized = false; > > } > > > > void thermal_zone_device_update(struct thermal_zone_device *tz) @@ > > -1574,6 +1588,7 @@ struct thermal_zone_device > *thermal_zone_device_register(const char *type, > > if (!tz->ops->get_temp) > > thermal_zone_device_set_polling(tz, 0); > > > > + thermal_zone_device_reset(tz); > > thermal_zone_device_update(tz); > > > > return tz; > > diff --git a/drivers/thermal/thermal_core.h > > b/drivers/thermal/thermal_core.h index 0531c75..6d9ffa5 100644 > > --- a/drivers/thermal/thermal_core.h > > +++ b/drivers/thermal/thermal_core.h > > @@ -41,6 +41,7 @@ struct thermal_instance { > > struct thermal_zone_device *tz; > > struct thermal_cooling_device *cdev; > > int trip; > > + bool initialized; > > unsigned long upper; /* Highest cooling state for this trip point */ > > unsigned long lower; /* Lowest cooling state for this trip point */ > > unsigned long target; /* expected cooling state */ > > diff --git a/include/linux/thermal.h b/include/linux/thermal.h index > > 5eac316..8650b0b 100644 > > --- a/include/linux/thermal.h > > +++ b/include/linux/thermal.h > > @@ -40,6 +40,9 @@ > > /* No upper/lower limit requirement */ > > #define THERMAL_NO_LIMIT ((u32)~0) > > > > +/* Invalid/uninitialized temperature */ > > +#define THERMAL_TEMP_INVALID -27400 > > + > > /* Unit conversion macros */ > > #define KELVIN_TO_CELSIUS(t) (long)(((long)t-2732 >= 0) ? \ > > ((long)t-2732+5)/10 : ((long)t-2732-5)/10) > > -- > > 1.9.1 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-pm" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info > > at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html