2024-04-25 14:12:37

by Rafael J. Wysocki

Subject: [PATCH v2 2/3] thermal/debugfs: Pass cooling device state to thermal_debug_cdev_add()

From: Rafael J. Wysocki <[email protected]>

If cdev_dt_seq_show() runs before the first state transition of a cooling
device, it will not print any state residency information for it, even
though it might be reasonably expected to print residency information for
the initial state of the cooling device.

For this reason, rearrange the code to get the initial state of a cooling
device at the registration time and pass it to thermal_debug_cdev_add(),
so that the latter can create a duration record for that state which will
allow cdev_dt_seq_show() to print its residency information.

Fixes: 755113d76786 ("thermal/debugfs: Add thermal cooling device debugfs information")
Reported-by: Lukasz Luba <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
---
drivers/thermal/thermal_core.c | 9 +++++++--
drivers/thermal/thermal_debugfs.c | 12 ++++++++++--
drivers/thermal/thermal_debugfs.h | 4 ++--
3 files changed, 19 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
@@ -935,6 +935,7 @@ __thermal_cooling_device_register(struct
{
struct thermal_cooling_device *cdev;
struct thermal_zone_device *pos = NULL;
+ unsigned long current_state;
int id, ret;

if (!ops || !ops->get_max_state || !ops->get_cur_state ||
@@ -972,6 +973,10 @@ __thermal_cooling_device_register(struct
if (ret)
goto out_cdev_type;

+ ret = cdev->ops->get_cur_state(cdev, &current_state);
+ if (ret)
+ goto out_cdev_type;
+
thermal_cooling_device_setup_sysfs(cdev);

ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
@@ -985,6 +990,8 @@ __thermal_cooling_device_register(struct
return ERR_PTR(ret);
}

+ thermal_debug_cdev_add(cdev, current_state);
+
/* Add 'this' new cdev to the global cdev list */
mutex_lock(&thermal_list_lock);

@@ -1000,8 +1007,6 @@ __thermal_cooling_device_register(struct

mutex_unlock(&thermal_list_lock);

- thermal_debug_cdev_add(cdev);
-
return cdev;

out_cooling_dev:
Index: linux-pm/drivers/thermal/thermal_debugfs.c
===================================================================
--- linux-pm.orig/drivers/thermal/thermal_debugfs.c
+++ linux-pm/drivers/thermal/thermal_debugfs.c
@@ -466,8 +466,9 @@ void thermal_debug_cdev_state_update(con
* Allocates a cooling device object for debug, initializes the
* statistics and create the entries in sysfs.
* @cdev: a pointer to a cooling device
+ * @state: current state of the cooling device
*/
-void thermal_debug_cdev_add(struct thermal_cooling_device *cdev)
+void thermal_debug_cdev_add(struct thermal_cooling_device *cdev, int state)
{
struct thermal_debugfs *thermal_dbg;
struct cdev_debugfs *cdev_dbg;
@@ -484,9 +485,16 @@ void thermal_debug_cdev_add(struct therm
INIT_LIST_HEAD(&cdev_dbg->durations[i]);
}

- cdev_dbg->current_state = 0;
+ cdev_dbg->current_state = state;
cdev_dbg->timestamp = ktime_get();

+ /*
+ * Create a record for the initial cooling device state, so its
+ * duration will be printed by cdev_dt_seq_show() as expected if it
+ * runs before the first state transition.
+ */
+ thermal_debugfs_cdev_record_get(thermal_dbg, cdev_dbg->durations, state);
+
debugfs_create_file("trans_table", 0400, thermal_dbg->d_top,
thermal_dbg, &tt_fops);

Index: linux-pm/drivers/thermal/thermal_debugfs.h
===================================================================
--- linux-pm.orig/drivers/thermal/thermal_debugfs.h
+++ linux-pm/drivers/thermal/thermal_debugfs.h
@@ -2,7 +2,7 @@

#ifdef CONFIG_THERMAL_DEBUGFS
void thermal_debug_init(void);
-void thermal_debug_cdev_add(struct thermal_cooling_device *cdev);
+void thermal_debug_cdev_add(struct thermal_cooling_device *cdev, int state);
void thermal_debug_cdev_remove(struct thermal_cooling_device *cdev);
void thermal_debug_cdev_state_update(const struct thermal_cooling_device *cdev, int state);
void thermal_debug_tz_add(struct thermal_zone_device *tz);
@@ -14,7 +14,7 @@ void thermal_debug_tz_trip_down(struct t
void thermal_debug_update_trip_stats(struct thermal_zone_device *tz);
#else
static inline void thermal_debug_init(void) {}
-static inline void thermal_debug_cdev_add(struct thermal_cooling_device *cdev) {}
+static inline void thermal_debug_cdev_add(struct thermal_cooling_device *cdev, int state) {}
static inline void thermal_debug_cdev_remove(struct thermal_cooling_device *cdev) {}
static inline void thermal_debug_cdev_state_update(const struct thermal_cooling_device *cdev,
int state) {}

2024-04-25 20:32:45

by Lukasz Luba

Subject: Re: [PATCH v2 2/3] thermal/debugfs: Pass cooling device state to thermal_debug_cdev_add()

On 4/25/24 15:04, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <[email protected]>
>
> If cdev_dt_seq_show() runs before the first state transition of a cooling
> device, it will not print any state residency information for it, even
> though it might be reasonably expected to print residency information for
> the initial state of the cooling device.
>
> For this reason, rearrange the code to get the initial state of a cooling
> device at the registration time and pass it to thermal_debug_cdev_add(),
> so that the latter can create a duration record for that state which will
> allow cdev_dt_seq_show() to print its residency information.
>
> Fixes: 755113d76786 ("thermal/debugfs: Add thermal cooling device debugfs information")
> Reported-by: Lukasz Luba <[email protected]>
> Signed-off-by: Rafael J. Wysocki <[email protected]>
> ---
> drivers/thermal/thermal_core.c | 9 +++++++--
> drivers/thermal/thermal_debugfs.c | 12 ++++++++++--
> drivers/thermal/thermal_debugfs.h | 4 ++--
> 3 files changed, 19 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
> @@ -935,6 +935,7 @@ __thermal_cooling_device_register(struct
> {
> struct thermal_cooling_device *cdev;
> struct thermal_zone_device *pos = NULL;
> + unsigned long current_state;
> int id, ret;
>
> if (!ops || !ops->get_max_state || !ops->get_cur_state ||
> @@ -972,6 +973,10 @@ __thermal_cooling_device_register(struct
> if (ret)
> goto out_cdev_type;
>
> + ret = cdev->ops->get_cur_state(cdev, &current_state);
> + if (ret)
> + goto out_cdev_type;
> +
> thermal_cooling_device_setup_sysfs(cdev);
>
> ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
> @@ -985,6 +990,8 @@ __thermal_cooling_device_register(struct
> return ERR_PTR(ret);
> }
>
> + thermal_debug_cdev_add(cdev, current_state);
> +
> /* Add 'this' new cdev to the global cdev list */
> mutex_lock(&thermal_list_lock);
>
> @@ -1000,8 +1007,6 @@ __thermal_cooling_device_register(struct
>
> mutex_unlock(&thermal_list_lock);
>
> - thermal_debug_cdev_add(cdev);
> -
> return cdev;
>
> out_cooling_dev:
> Index: linux-pm/drivers/thermal/thermal_debugfs.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/thermal_debugfs.c
> +++ linux-pm/drivers/thermal/thermal_debugfs.c
> @@ -466,8 +466,9 @@ void thermal_debug_cdev_state_update(con
> * Allocates a cooling device object for debug, initializes the
> * statistics and create the entries in sysfs.
> * @cdev: a pointer to a cooling device
> + * @state: current state of the cooling device
> */
> -void thermal_debug_cdev_add(struct thermal_cooling_device *cdev)
> +void thermal_debug_cdev_add(struct thermal_cooling_device *cdev, int state)
> {
> struct thermal_debugfs *thermal_dbg;
> struct cdev_debugfs *cdev_dbg;
> @@ -484,9 +485,16 @@ void thermal_debug_cdev_add(struct therm
> INIT_LIST_HEAD(&cdev_dbg->durations[i]);
> }
>
> - cdev_dbg->current_state = 0;
> + cdev_dbg->current_state = state;
> cdev_dbg->timestamp = ktime_get();
>
> + /*
> + * Create a record for the initial cooling device state, so its
> + * duration will be printed by cdev_dt_seq_show() as expected if it
> + * runs before the first state transition.
> + */
> + thermal_debugfs_cdev_record_get(thermal_dbg, cdev_dbg->durations, state);
> +
> debugfs_create_file("trans_table", 0400, thermal_dbg->d_top,
> thermal_dbg, &tt_fops);
>
> Index: linux-pm/drivers/thermal/thermal_debugfs.h
> ===================================================================
> --- linux-pm.orig/drivers/thermal/thermal_debugfs.h
> +++ linux-pm/drivers/thermal/thermal_debugfs.h
> @@ -2,7 +2,7 @@
>
> #ifdef CONFIG_THERMAL_DEBUGFS
> void thermal_debug_init(void);
> -void thermal_debug_cdev_add(struct thermal_cooling_device *cdev);
> +void thermal_debug_cdev_add(struct thermal_cooling_device *cdev, int state);
> void thermal_debug_cdev_remove(struct thermal_cooling_device *cdev);
> void thermal_debug_cdev_state_update(const struct thermal_cooling_device *cdev, int state);
> void thermal_debug_tz_add(struct thermal_zone_device *tz);
> @@ -14,7 +14,7 @@ void thermal_debug_tz_trip_down(struct t
> void thermal_debug_update_trip_stats(struct thermal_zone_device *tz);
> #else
> static inline void thermal_debug_init(void) {}
> -static inline void thermal_debug_cdev_add(struct thermal_cooling_device *cdev) {}
> +static inline void thermal_debug_cdev_add(struct thermal_cooling_device *cdev, int state) {}
> static inline void thermal_debug_cdev_remove(struct thermal_cooling_device *cdev) {}
> static inline void thermal_debug_cdev_state_update(const struct thermal_cooling_device *cdev,
> int state) {}
>
>
>
>

Reviewed-by: Lukasz Luba <[email protected]>