From 9dbdc63ae4029fba142229ea20d404ddd672d2d5 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 11 Mar 2025 08:51:19 +0900 Subject: [PATCH] thermal: core: Fix race between zone registration and system suspend BugLink: https://bugs.launchpad.net/bugs/2101915 [ Upstream commit cdf771ab476bd9acb0948f3088a277d5c3cacc6b ] If the registration of a thermal zone takes place at the time when system suspend is started, thermal_pm_notify() can run before the new thermal zone is added to thermal_tz_list and its "suspended" flag will not be set. Consequently, if __thermal_zone_device_update() is called for that thermal zone, it will not return early as expected which may cause some destructive interference with the system suspend or resume flow to occur. To avoid that, make thermal_zone_init_complete() introduced previously set the "suspended" flag for new thermal zones if it runs during system suspend or resume. Fixes: 4e814173a8c4 ("thermal: core: Fix thermal zone suspend-resume synchronization") Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/8490245.NyiUUSuA9g@rjwysocki.net Reviewed-by: Lukasz Luba Signed-off-by: Sasha Levin Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- drivers/thermal/thermal_core.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index 68c5c96a542d..e8df2f176f58 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -39,6 +39,8 @@ static DEFINE_MUTEX(thermal_governor_lock); static struct thermal_governor *def_governor; +static bool thermal_pm_suspended; + /* * Governor section: set of functions to handle thermal governors * @@ -1244,6 +1246,14 @@ static void thermal_zone_init_complete(struct thermal_zone_device *tz) mutex_lock(&tz->lock); tz->state &= ~TZ_STATE_FLAG_INIT; + /* + * If system suspend or resume is in progress at this point, the + * new thermal zone needs to be marked as suspended because + * thermal_pm_notify() has run already. + */ + if (thermal_pm_suspended) + tz->state |= TZ_STATE_FLAG_SUSPENDED; + __thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED); mutex_unlock(&tz->lock); @@ -1424,10 +1434,10 @@ thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *t } } - mutex_unlock(&thermal_list_lock); - thermal_zone_init_complete(tz); + mutex_unlock(&thermal_list_lock); + thermal_notify_tz_create(tz); thermal_debug_tz_add(tz); @@ -1646,6 +1656,8 @@ static int thermal_pm_notify(struct notifier_block *nb, case PM_SUSPEND_PREPARE: mutex_lock(&thermal_list_lock); + thermal_pm_suspended = true; + list_for_each_entry(tz, &thermal_tz_list, node) thermal_zone_pm_prepare(tz); @@ -1656,6 +1668,8 @@ static int thermal_pm_notify(struct notifier_block *nb, case PM_POST_SUSPEND: mutex_lock(&thermal_list_lock); + thermal_pm_suspended = false; + list_for_each_entry(tz, &thermal_tz_list, node) thermal_zone_pm_complete(tz);