From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eduardo Valentin Subject: Re: [PATCH 2/3] Thermal: handle thermal zone device properly during system sleep Date: Wed, 25 Mar 2015 10:40:28 -0400 Message-ID: <20150325144026.GA19384@developer.hsd1.ca.comcast.net> References: <1427174490-7974-1-git-send-email-rui.zhang@intel.com> <1427174490-7974-3-git-send-email-rui.zhang@intel.com> <20150324150647.GC29155@developer.hsd1.ca.comcast.net> <744357E9AAD1214791ACBA4B0B909263014BA997@SHSMSX101.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="jRHKVT23PllUwdXP" Return-path: Received: from mail-pd0-f179.google.com ([209.85.192.179]:34310 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753244AbbCYOkb (ORCPT ); Wed, 25 Mar 2015 10:40:31 -0400 Content-Disposition: inline In-Reply-To: <744357E9AAD1214791ACBA4B0B909263014BA997@SHSMSX101.ccr.corp.intel.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Zhang, Rui" Cc: "linux-pm@vger.kernel.org" , "stable@vger.kernel.org" --jRHKVT23PllUwdXP Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Mar 25, 2015 at 02:25:06AM +0000, Zhang, Rui wrote: >=20 >=20 > > -----Original Message----- > > From: linux-pm-owner@vger.kernel.org [mailto:linux-pm- > > owner@vger.kernel.org] On Behalf Of Eduardo Valentin > > Sent: Tuesday, March 24, 2015 11:07 PM > > To: Zhang, Rui > > Cc: linux-pm@vger.kernel.org; stable@vger.kernel.org > > Subject: Re: [PATCH 2/3] Thermal: handle thermal zone device properly d= uring > > system sleep > > Importance: High > >=20 > > Hey Rui > >=20 > > 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 > > > 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 p= hasing > > > out ACPI bus. > > > > > > Signed-off-by: Aaron Lu > > > Signed-off-by: Zhang Rui > > > > > > 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: #3.18+ > > > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=3D78201 > > > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=3D91411 > > > Tested-by: Manuel Krause > > > Tested-by: szegad > > > Tested-by: prash > > > Tested-by: amish > > > Tested-by: Matthias > > > Signed-off-by: Zhang Rui > > > --- > > > 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 > > > #include > > > #include > > > +#include > > > > > > #define CREATE_TRACE_POINTS > > > #include > > > @@ -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; > >=20 > > Should this variable be considered to be accessed using a lock? > >=20 > 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? >=20 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; > > > + =2E. 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) > >=20 > > I believe thermal_pm_notify sounds a better naming for this case. > >=20 > Okay, will change it to thermal_pm_notify in next version. >=20 > > > +{ > > > + struct thermal_zone_device *tz; > > > + > > > + switch (mode) { > > > + case PM_HIBERNATION_PREPARE: > > > + case PM_RESTORE_PREPARE: > > > + case PM_SUSPEND_PREPARE: > > > + no_thermal_update =3D true; > > > + break; > > > + case PM_POST_HIBERNATION: > > > + case PM_POST_RESTORE: > > > + case PM_POST_SUSPEND: > > > + no_thermal_update =3D 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 =3D thermal_notify; > >=20 > > I believe you can declare thermal_pm_nb already with the callback > > initialized: > >=20 > >=20 > >=20 > > static struct notifier_block thermal_pm_nb =3D { > > .notifier_call =3D thermal_notify, > > }; > >=20 > Yes, will do this. >=20 > Thanks, > rui > >=20 > > just put it after the thermal_notify function. > >=20 > > > + 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@vger.kernel.org More majordomo info > > > at http://vger.kernel.org/majordomo-info.html --jRHKVT23PllUwdXP Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBAgAGBQJVEsjaAAoJEMLUO4d9pOJWcosH/36FElIpLKQ/WeRauWRtrQZV t7MIYbExuyeVlBYAdSgD3vzqAJb1CUb/Jr1IEbgIC6c6TCn+ciqXfyLK0tJfSsK8 lpgFT1KXWFH4HaHxiMrSp1pcrV0zWIgCrPAS4TnS/twJodhKO59ETn1zOFkuHfi/ WJPOd6BGwQEovmtFWtDCUTPTE0d7XzXB/wCDZgSKuinT0t2gYBxDaxVIgYLJwPg7 xh6R2Jc9tOi4iX2jufj66CBwgewdmJNpkBOegkcRZTKF0dQ8NAmv30Tc67WtECbV ua8F9JdOMK9zLxU+DlviGY6a0KHXID/iBlRV+riIO60Nm0NuK165zFolxF7p8As= =ddVb -----END PGP SIGNATURE----- --jRHKVT23PllUwdXP--