From mboxrd@z Thu Jan 1 00:00:00 1970 From: Javi Merino Subject: Re: [PATCH 2/3][v2] Thermal: handle thermal zone device properly during system sleep Date: Wed, 28 Oct 2015 10:33:11 +0000 Message-ID: <20151028103310.GA2686@e104805> References: <263fad83855e3da9c768fec15f496a308953d05a.1445828170.git.yu.c.chen@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Received: from foss.arm.com ([217.140.101.70]:33201 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753887AbbJ1KdO (ORCPT ); Wed, 28 Oct 2015 06:33:14 -0400 Content-Disposition: inline In-Reply-To: <263fad83855e3da9c768fec15f496a308953d05a.1445828170.git.yu.c.chen@intel.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: rui.zhang@intel.com, Chen Yu Cc: edubezval@gmail.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Hi Yu, some minor nits below. Other than that, you can add my Reviewed-by: Javi Merino On Mon, Oct 26, 2015 at 11:14:31AM +0800, Chen Yu wrote: > From: Zhang Rui > > 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 19593a1fb1f6 ("ACPI / fan: convert to platform driver") > Because, with above 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: #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 > Tested-by: szegad > Tested-by: prash > Tested-by: amish > Tested-by: Matthias > Signed-off-by: Zhang Rui > Signed-off-by: Chen Yu > --- > drivers/thermal/thermal_core.c | 45 +++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 44 insertions(+), 1 deletion(-) > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > index 682bc1e..abeb995 100644 > --- a/drivers/thermal/thermal_core.c > +++ b/drivers/thermal/thermal_core.c > @@ -37,6 +37,7 @@ > #include > #include > #include > +#include > > #define CREATE_TRACE_POINTS > #include > @@ -59,6 +60,8 @@ static LIST_HEAD(thermal_governor_list); > static DEFINE_MUTEX(thermal_list_lock); > static DEFINE_MUTEX(thermal_governor_lock); > > +static atomic_t in_suspend; > + > static struct thermal_governor *def_governor; > > static struct thermal_governor *__find_governor(const char *name) > @@ -554,6 +557,9 @@ void thermal_zone_device_update(struct thermal_zone_device *tz) > { > int count; > > + if (atomic_read(&in_suspend)) > + return; > + > if (!tz->ops->get_temp) > return; > > @@ -2155,9 +2161,39 @@ static void thermal_unregister_governors(void) > thermal_gov_power_allocator_unregister(); > } > > +static int thermal_pm_notify(struct notifier_block *nb, > + unsigned long mode, void *_unused) > +{ > + struct thermal_zone_device *tz; > + > + switch (mode) { > + case PM_HIBERNATION_PREPARE: > + case PM_RESTORE_PREPARE: > + case PM_SUSPEND_PREPARE: > + atomic_set(&in_suspend, 1); > + break; > + case PM_POST_HIBERNATION: > + case PM_POST_RESTORE: > + case PM_POST_SUSPEND: > + atomic_set(&in_suspend, 0); > + 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 struct notifier_block thermal_pm_nb = { > + .notifier_call = thermal_pm_notify, > +}; > + > static int __init thermal_init(void) > { > - int result; > + int result, notifier_result; > > result = thermal_register_governors(); > if (result) > @@ -2175,6 +2211,12 @@ static int __init thermal_init(void) > if (result) > goto exit_netlink; > > + notifier_result = register_pm_notifier(&thermal_pm_nb); No need to define a new variable, you can use result. > + if (notifier_result) > + pr_err("Thermal: Can not register suspend notifier" pr_warn ? > + "for thermal framework, return %d\n", Please keep the string in the same line, don't break it. I know that checkpatch.pl complains, but the CodingStyle says don't break them: "However, never break user-visible strings such as printk messages, because that breaks the ability to grep for them" https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/CodingStyle#n86 Cheers, Javi > + notifier_result); > + > return 0; > > exit_netlink: > @@ -2194,6 +2236,7 @@ error: > > static void __exit thermal_exit(void) > { > + unregister_pm_notifier(&thermal_pm_nb); > of_thermal_destroy_zones(); > genetlink_exit(); > class_unregister(&thermal_class); > -- > 1.8.4.2 >