Re: [PATCH v1] thermal: core: Clean up thermal_list_lock locking

Daniel Lezcano
2023-04-01T20:45:03Z

On 22/03/2023 20:34, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Once thermal_list_lock has been acquired in
> __thermal_cooling_device_register(), it is not necessary to drop it
> and take it again until all of the thermal zones have been updated,
> so change the code accordingly.
>
> No expected functional impact.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---

Looks good to me, shall I pick it in my branch ?

> drivers/thermal/thermal_core.c | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
>
> Index: linux-pm/drivers/thermal/thermal_core.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/thermal_core.c
> +++ linux-pm/drivers/thermal/thermal_core.c
> @@ -826,8 +826,6 @@ static void bind_cdev(struct thermal_coo
> const struct thermal_zone_params *tzp;
> struct thermal_zone_device *pos = NULL;
>
> - mutex_lock(&thermal_list_lock);
> -
> list_for_each_entry(pos, &thermal_tz_list, node) {
> if (!pos->tzp && !pos->ops->bind)
> continue;
> @@ -854,8 +852,6 @@ static void bind_cdev(struct thermal_coo
> tzp->tbp[i].weight);
> }
> }
> -
> - mutex_unlock(&thermal_list_lock);
> }
>
> /**
> @@ -933,17 +929,17 @@ __thermal_cooling_device_register(struct
>
> /* Add 'this' new cdev to the global cdev list */
> mutex_lock(&thermal_list_lock);
> +
> list_add(&cdev->node, &thermal_cdev_list);
> - mutex_unlock(&thermal_list_lock);
>
> /* Update binding information for 'this' new cdev */
> bind_cdev(cdev);
>
> - mutex_lock(&thermal_list_lock);
> list_for_each_entry(pos, &thermal_tz_list, node)
> if (atomic_cmpxchg(&pos->need_update, 1, 0))
> thermal_zone_device_update(pos,
> THERMAL_EVENT_UNSPECIFIED);
> +
> mutex_unlock(&thermal_list_lock);
>
> return cdev;
>
>
>

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