| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <c07b9fe7-5d28-c72a-a9d9-e612b07b0b75@linaro.org>
Date: Wed, 16 Feb 2022 19:44:26 +0100
From: Daniel Lezcano <daniel.lezcano@...aro.org>
To: Manaf Meethalavalappu Pallikunhi <quic_manafm@...cinc.com>,
Lukasz Luba <lukasz.luba@....com>,
"Rafael J . Wysocki" <rafael@...nel.org>,
Amit Kucheria <amitk@...nel.org>,
Zhang Rui <rui.zhang@...el.com>
Cc: linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v5] drivers: thermal: clear all mitigation when thermal
zone is disabled
On 27/01/2022 19:11, Manaf Meethalavalappu Pallikunhi wrote:
> Whenever a thermal zone is in trip violated state, there is a chance
> that the same thermal zone mode can be disabled either via
> thermal core API or via thermal zone sysfs. Once it is disabled,
> the framework bails out any re-evaluation of thermal zone. It leads
> to a case where if it is already in mitigation state, it will stay
> the same state forever.
>
> To avoid above mentioned issue, add support to bind/unbind
> governor from thermal zone during thermal zone mode change request
> and clear all existing throttling in governor unbind_from_tz()
> callback.
Manaf,
can you clarify when / why is needed to disable a thermal zone at runtime?
> Suggested-by: Daniel Lezcano <daniel.lezcano@...aro.org>
> Signed-off-by: Manaf Meethalavalappu Pallikunhi <quic_manafm@...cinc.com>
> ---
> drivers/thermal/gov_power_allocator.c | 3 +++
> drivers/thermal/gov_step_wise.c | 26 ++++++++++++++++++++++++++
> drivers/thermal/thermal_core.c | 31 +++++++++++++++++++++++++++----
> 3 files changed, 56 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c
> index 13e3757..9ff0c5f 100644
> --- a/drivers/thermal/gov_power_allocator.c
> +++ b/drivers/thermal/gov_power_allocator.c
> @@ -696,6 +696,9 @@ static void power_allocator_unbind(struct thermal_zone_device *tz)
>
> dev_dbg(&tz->device, "Unbinding from thermal zone %d\n", tz->id);
>
> + tz->passive = 0;
> + allow_maximum_power(tz, true);
> +
> if (params->allocated_tzp) {
> kfree(tz->tzp);
> tz->tzp = NULL;
> diff --git a/drivers/thermal/gov_step_wise.c b/drivers/thermal/gov_step_wise.c
> index 12acb12..2d2186b 100644
> --- a/drivers/thermal/gov_step_wise.c
> +++ b/drivers/thermal/gov_step_wise.c
> @@ -168,6 +168,31 @@ static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip)
> }
>
> /**
> + * step_wise_unbind() - unbind the step_wise governor to a thermal zone
> + * @tz: thermal zone to unbind it to
> + *
> + * Clear all previous throttling and reset passive counter.
> + *
> + */
> +static void step_wise_unbind(struct thermal_zone_device *tz)
> +{
> + struct thermal_instance *instance;
> +
> + dev_dbg(&tz->device, "Unbinding from thermal zone %d\n", tz->id);
> +
> + mutex_lock(&tz->lock);
> + tz->passive = 0;
> + list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
> + instance->initialized = false;
> + instance->target = THERMAL_NO_TARGET;
> + mutex_lock(&instance->cdev->lock);
> + __thermal_cdev_update(instance->cdev);
> + mutex_unlock(&instance->cdev->lock);
> + }
> + mutex_unlock(&tz->lock);
> +}
> +
> +/**
> * step_wise_throttle - throttles devices associated with the given zone
> * @tz: thermal_zone_device
> * @trip: trip point index
> @@ -196,6 +221,7 @@ static int step_wise_throttle(struct thermal_zone_device *tz, int trip)
>
> static struct thermal_governor thermal_gov_step_wise = {
> .name = "step_wise",
> + .unbind_from_tz = step_wise_unbind,
> .throttle = step_wise_throttle,
> };
> THERMAL_GOVERNOR_DECLARE(thermal_gov_step_wise);
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 82654dc..34726d3 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -274,6 +274,26 @@ static int __init thermal_register_governors(void)
> return ret;
> }
>
> +static void thermal_governor_attach(struct thermal_zone_device *tz)
> +{
> + mutex_lock(&thermal_governor_lock);
> + if (tz->governor && tz->governor->bind_to_tz) {
> + if (tz->governor->bind_to_tz(tz))
> + dev_err(&tz->device,
> + "governor %s failed to bind to thermal zone %s\n",
> + tz->governor->name, tz->type);
> + }
> + mutex_unlock(&thermal_governor_lock);
> +}
> +
> +static void thermal_governor_detach(struct thermal_zone_device *tz)
> +{
> + mutex_lock(&thermal_governor_lock);
> + if (tz->governor && tz->governor->unbind_from_tz)
> + tz->governor->unbind_from_tz(tz);
> + mutex_unlock(&thermal_governor_lock);
> +}
> +
> /*
> * Zone update section: main control loop applied to each zone while monitoring
> *
> @@ -449,12 +469,15 @@ static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
>
> mutex_unlock(&tz->lock);
>
> - thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
> -
> - if (mode == THERMAL_DEVICE_ENABLED)
> + if (mode == THERMAL_DEVICE_ENABLED) {
> + thermal_governor_attach(tz);
> + thermal_zone_device_init(tz);
> + thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
> thermal_notify_tz_enable(tz->id);
> - else
> + } else {
> + thermal_governor_detach(tz);
> thermal_notify_tz_disable(tz->id);
> + }
>
> return ret;
> }
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
Powered by blists - more mailing lists