[PATCH v1 0/2] thermal: core: Revert two cosmetic update that go against driver core changes

[PATCH v1 0/2] thermal: core: Revert two cosmetic update that go against driver core changes

[Rafael J. Wysocki]

Hi All,

Two recent thermal core commits restored the usage of class_create()
into the thermal core as a cleanup matter, but that goes against the
driver core plans to get rid of that function.

Revert these two commits and let class_create() be eliminated.

Thanks!

[PATCH v1 1/2] Revert "thermal/core: Use the thermal class pointer as init guard"

[Rafael J. Wysocki]

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

This reverts commit 499274d078d0 ("thermal/core: Use the thermal class
pointer as init guard") because it depends on another commit that needs
to be reverted.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/thermal/thermal_core.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 28a20d4b475c..2d9d8740491f 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -890,6 +890,7 @@ static void thermal_unbind_cdev_from_trip(struct thermal_zone_device *tz,
 }
 
 static struct class *thermal_class __ro_after_init;
+static bool thermal_class_unavailable __ro_after_init = true;
 
 static inline
 void print_bind_err_msg(struct thermal_zone_device *tz,
@@ -973,7 +974,7 @@ thermal_cooling_device_alloc(const char *type, const struct thermal_cooling_devi
 	    !ops->set_cur_state)
 		return ERR_PTR(-EINVAL);
 
-	if (!thermal_class)
+	if (thermal_class_unavailable)
 		return ERR_PTR(-ENODEV);
 
 	cdev = kzalloc_obj(*cdev);
@@ -1447,7 +1448,7 @@ thermal_zone_device_register_with_trips(const char *type,
 	if (polling_delay && passive_delay > polling_delay)
 		return ERR_PTR(-EINVAL);
 
-	if (!thermal_class)
+	if (thermal_class_unavailable)
 		return ERR_PTR(-ENODEV);
 
 	tz = kzalloc_flex(*tz, trips, num_trips);
@@ -1745,7 +1746,7 @@ static void __thermal_pm_prepare(void)
 
 void thermal_pm_prepare(void)
 {
-	if (!thermal_class)
+	if (thermal_class_unavailable)
 		return;
 
 	__thermal_pm_prepare();
@@ -1776,7 +1777,7 @@ void thermal_pm_complete(void)
 {
 	struct thermal_zone_device *tz;
 
-	if (!thermal_class)
+	if (thermal_class_unavailable)
 		return;
 
 	guard(mutex)(&thermal_list_lock);
@@ -1815,6 +1816,8 @@ static int __init thermal_init(void)
 	}
 
 	thermal_class = tc;
+	thermal_class_unavailable = false;
+
 	return 0;
 
 unregister_governors:
-- 
2.51.0

[PATCH v1 2/2] Revert "thermal/core: Allocate the thermal class dynamically"

[Rafael J. Wysocki]

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

This reverts commit 34f54003643e ("thermal/core: Allocate the thermal
class dynamically") that went against driver core changes aiming at the
elimination of class_create() [1].

No intentional functional impact.

Link: https://lore.kernel.org/linux-pm/2026082411-flask-rewire-434f@gregkh/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/thermal/thermal_core.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 2d9d8740491f..82e2f0d8a26d 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -889,7 +889,9 @@ static void thermal_unbind_cdev_from_trip(struct thermal_zone_device *tz,
 	kfree(pos);
 }
 
-static struct class *thermal_class __ro_after_init;
+static const struct class thermal_class = {
+	.name = "thermal",
+};
 static bool thermal_class_unavailable __ro_after_init = true;
 
 static inline
@@ -1011,7 +1013,7 @@ int thermal_cooling_device_add(struct thermal_cooling_device *cdev, void *devdat
 	mutex_init(&cdev->lock);
 	INIT_LIST_HEAD(&cdev->thermal_instances);
 	cdev->updated = false;
-	cdev->device.class = thermal_class;
+	cdev->device.class = &thermal_class;
 	cdev->device.release = thermal_cdev_release;
 	device_initialize(&cdev->device);
 	cdev->devdata = devdata;
@@ -1484,7 +1486,7 @@ thermal_zone_device_register_with_trips(const char *type,
 	if (!tz->ops.critical)
 		tz->ops.critical = thermal_zone_device_critical;
 
-	tz->device.class = thermal_class;
+	tz->device.class = &thermal_class;
 	tz->device.release = thermal_zone_device_release;
 	tz->devdata = devdata;
 	tz->num_trips = num_trips;
@@ -1790,7 +1792,6 @@ void thermal_pm_complete(void)
 
 static int __init thermal_init(void)
 {
-	struct class *tc;
 	int result;
 
 	thermal_debug_init();
@@ -1809,13 +1810,10 @@ static int __init thermal_init(void)
 	if (result)
 		goto unregister_governors;
 
-	tc = class_create("thermal");
-	if (IS_ERR(tc)) {
-		result = PTR_ERR(tc);
+	result = class_register(&thermal_class);
+	if (result)
 		goto unregister_governors;
-	}
 
-	thermal_class = tc;
 	thermal_class_unavailable = false;
 
 	return 0;
-- 
2.51.0

Re: [PATCH v1 0/2] thermal: core: Revert two cosmetic update that go against driver core changes

[Greg Kroah-Hartman]

On Mon, Aug 24, 2026 at 07:50:52PM +0200, Rafael J. Wysocki wrote:
> Hi All,
> 
> Two recent thermal core commits restored the usage of class_create()
> into the thermal core as a cleanup matter, but that goes against the
> driver core plans to get rid of that function.
> 
> Revert these two commits and let class_create() be eliminated.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>