Hi Eduardo, Thanks for your review and sorry for that I missed your email. > -----Original Message----- > From: linux-pm-owner@xxxxxxxxxxxxxxx [mailto:linux-pm- > owner@xxxxxxxxxxxxxxx] On Behalf Of Eduardo Valentin > Sent: Friday, January 01, 2016 2:44 AM > To: Chen, Yu C > Cc: Zhang, Rui; javi.merino@xxxxxxx; linux-pm@xxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx > Subject: Re: [PATCH 1/3][v3] Thermal: initialize thermal zone device correctly > > For some reason, I thought Rui had picked this already. > > Anyways, here are a couple of comments: > > On Fri, Oct 30, 2015 at 04:31:47PM +0800, Chen Yu wrote: > > From: Zhang Rui <rui.zhang@xxxxxxxxx> > > > > 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. And since the step_wise governor is the only one that > > uses trends, so it's the only thermal governor that needs to be > > updated. > > > > 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> > > Reviewed-by: Javi Merino <javi.merino@xxxxxxx> > > Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> > > Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx> > > --- > > drivers/thermal/step_wise.c | 17 +++++++++++++++-- > > drivers/thermal/thermal_core.c | 19 +++++++++++++++++-- > > drivers/thermal/thermal_core.h | 1 + > > I would prefer if you could split this patch in two. One for thermal core > another one for step wise. [Yu] It would be better if we can split this patch into two, for stable material. What do you think, Rui? > > > include/linux/thermal.h | 3 +++ > > 4 files changed, 36 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.c > > index 2f9f708..ea9366a 100644 > > --- a/drivers/thermal/step_wise.c > > +++ b/drivers/thermal/step_wise.c > > @@ -63,6 +63,19 @@ 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)); > > + } else { > > + next_target = THERMAL_NO_TARGET; > > + } > > + > > + return next_target; > > + } > > + > > switch (trend) { > > case THERMAL_TREND_RAISING: > > if (throttle) { > > @@ -149,7 +162,7 @@ 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 +174,7 > @@ > > 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 */ > > } > > > > Considering that I understood the problem and your proposal well, I would > say these changes on step wise are the perfect case for setting up a > step_wise.bind_to_tz(). bind_to_tz() is already designed as an opportunity > for governor to check the thermal zone status at the time of binding. > Remember that moving to bind_to_tz() covers not only registration time, but > governor switching too (say, user chooses user_space, then step_wise). [Yu] The code change in step_wise. get_target_state is mainly for suspend/resume scenario, which is not involved with thermal zone/governor bindings IMO. > > The above code seams to be correct, but after reviewing the code of > step_wise.throttle(), I would say it is already complicated and deserves > simplification, when possible. > > > > > diff --git a/drivers/thermal/thermal_core.c > > b/drivers/thermal/thermal_core.c index d9e525c..682bc1e 100644 > > --- a/drivers/thermal/thermal_core.c > > +++ b/drivers/thermal/thermal_core.c > > @@ -532,8 +532,22 @@ 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); } > > + > > +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) @@ > > -1900,6 +1914,7 @@ struct thermal_zone_device > > *thermal_zone_device_register(const char *type, > > > > INIT_DELAYED_WORK(&(tz->poll_queue), > thermal_zone_device_check); > > > > + 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 d7ac1fc..749d41a 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 > > 157d366..5bcabc7 100644 > > --- a/include/linux/thermal.h > > +++ b/include/linux/thermal.h > > @@ -43,6 +43,9 @@ > > /* Default weight of a bound cooling device */ #define > > THERMAL_WEIGHT_DEFAULT 0 > > > > +/* use value, which < 0K, to indicate an invalid/uninitialized temperature > */ > > +#define THERMAL_TEMP_INVALID -274000 > > + > > /* Unit conversion macros */ > > #define KELVIN_TO_CELSIUS(t) (long)(((long)t-2732 >= 0) ? \ > > ((long)t-2732+5)/10 : ((long)t-2732-5)/10) > > -- > > 1.8.4.2 -- 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