On Wed, Mar 25, 2015 at 02:25:06AM +0000, Zhang, Rui wrote: > > > > -----Original Message----- > > From: linux-pm-owner@xxxxxxxxxxxxxxx [mailto:linux-pm- > > owner@xxxxxxxxxxxxxxx] On Behalf Of Eduardo Valentin > > Sent: Tuesday, March 24, 2015 11:07 PM > > To: Zhang, Rui > > Cc: linux-pm@xxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx > > Subject: Re: [PATCH 2/3] Thermal: handle thermal zone device properly during > > system sleep > > Importance: High > > > > Hey Rui > > > > On Tue, Mar 24, 2015 at 01:21:29PM +0800, Zhang Rui wrote: > > > Current thermal code does not handle system sleep well because 1. the > > > cooling device cooling state may be changed during suspend 2. the > > > previous temperature reading becomes invalid after resumed because > > > it is got before system sleep > > > 3. updating thermal zone device during suspending/resuming > > > is wrong because some devices may have already been suspended > > > or may have not been resumed. > > > > > > Thus, the proper way to do this is to cancel all thermal zone device > > > update requirements during suspend/resume, and after all the devices > > > have been resumed, reset and update every registered thermal zone > > > devices. > > > > > > This also fixes a regression introduced by commit > > > 19593a1fb1f6718406afca5b867dab184289d406 > > > Author: Aaron Lu <aaron.lu@xxxxxxxxx> > > > Date: Tue Nov 19 16:59:20 2013 +0800 > > > > > > ACPI / fan: convert to platform driver > > > > > > Convert ACPI fan driver to a platform driver for the purpose of phasing > > > out ACPI bus. > > > > > > Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx> > > > Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> > > > > > > Because, with the commit applied, all the fan devices are attached to > > > the acpi_general_pm_domain, and they are turned on by the pm_domain > > > automatically after resume, without the awareness of thermal core. > > > > > > CC: <stable@xxxxxxxxxxxxxxx> #3.18+ > > > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=78201 > > > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=91411 > > > 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/thermal_core.c | 37 > > > +++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 37 insertions(+) > > > > > > diff --git a/drivers/thermal/thermal_core.c > > > b/drivers/thermal/thermal_core.c index 9d6f71b..9c03561 100644 > > > --- a/drivers/thermal/thermal_core.c > > > +++ b/drivers/thermal/thermal_core.c > > > @@ -37,6 +37,7 @@ > > > #include <linux/of.h> > > > #include <net/netlink.h> > > > #include <net/genetlink.h> > > > +#include <linux/suspend.h> > > > > > > #define CREATE_TRACE_POINTS > > > #include <trace/events/thermal.h> > > > @@ -59,6 +60,9 @@ static LIST_HEAD(thermal_governor_list); static > > > DEFINE_MUTEX(thermal_list_lock); static > > > DEFINE_MUTEX(thermal_governor_lock); > > > > > > +static struct notifier_block thermal_pm_nb; static bool > > > +no_thermal_update; > > > > Should this variable be considered to be accessed using a lock? > > > Hmmm, why? Because you access the variable out of the suspend path. > It is set once when entering suspend, and cleared once when resuming, > and this whole process is protected by the pm_mutex lock, right? > yeah, if you would be accessing it only inside the suspend path, but you have an extra reader... > > > + > > > static struct thermal_governor *def_governor; > > > > > > static struct thermal_governor *__find_governor(const char *name) @@ > > > -491,6 +495,9 @@ void thermal_zone_device_update(struct > > > thermal_zone_device *tz) { > > > int count; > > > > > > + if (no_thermal_update) > > > + return; > > > + .. right here. > > > if (!tz->ops->get_temp) > > > return; > > > > > > @@ -1823,6 +1830,33 @@ static void thermal_unregister_governors(void) > > > thermal_gov_user_space_unregister(); > > > } > > > > > > +static int thermal_notify(struct notifier_block *nb, > > > + unsigned long mode, void *_unused) > > > > I believe thermal_pm_notify sounds a better naming for this case. > > > Okay, will change it to thermal_pm_notify in next version. > > > > +{ > > > + struct thermal_zone_device *tz; > > > + > > > + switch (mode) { > > > + case PM_HIBERNATION_PREPARE: > > > + case PM_RESTORE_PREPARE: > > > + case PM_SUSPEND_PREPARE: > > > + no_thermal_update = true; > > > + break; > > > + case PM_POST_HIBERNATION: > > > + case PM_POST_RESTORE: > > > + case PM_POST_SUSPEND: > > > + no_thermal_update = false; > > > + list_for_each_entry(tz, &thermal_tz_list, node) { > > > + thermal_zone_device_reset(tz); > > > + thermal_zone_device_update(tz); > > > + } > > > + break; > > > + default: > > > + break; > > > + } > > > + return 0; > > > +} > > > + > > > + > > > static int __init thermal_init(void) > > > { > > > int result; > > > @@ -1843,6 +1877,9 @@ static int __init thermal_init(void) > > > if (result) > > > goto exit_netlink; > > > > > > + thermal_pm_nb.notifier_call = thermal_notify; > > > > I believe you can declare thermal_pm_nb already with the callback > > initialized: > > > > > > > > static struct notifier_block thermal_pm_nb = { > > .notifier_call = thermal_notify, > > }; > > > Yes, will do this. > > Thanks, > rui > > > > just put it after the thermal_notify function. > > > > > + register_pm_notifier(&thermal_pm_nb); > > > + > > > return 0; > > > > > > exit_netlink: > > > -- > > > 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
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