The paths thermal_zone%d and cooling_device%d are not intuitive and the
numbers are subject to change due to device tree change. This usually
leads to tree traversal in userspace code.
The patch creates `tz-by-name' and `cdev-by-name' for thermal zone and
cooling_device respectively.
Changes since v1 [1]:
* Split cooling device registration into a seperate patch
Changes since v2 [2]:
* Split improve error message in thermal zone registration
[1]: v1: https://lore.kernel.org/patchwork/patch/1139450/
[2]: v2: https://lkml.org/lkml/2019/12/4/1291
Wei Wang (3):
thermal: prevent cooling device with no type to be registered
thermal: improve error message in thermal zone registration
thermal: create softlink by name for thermal_zone and cooling_device
drivers/thermal/thermal_core.c | 55 +++++++++++++++++++++++++++-------
1 file changed, 44 insertions(+), 11 deletions(-)
--
2.24.0.393.g34dc348eaf-goog
commit 54fa38cc2eda ("thermal: core: prevent zones with no types to be
registered") added logic to prevent thermal zone with empty type to be
registered. Similarly, there are APIs that rely on cdev->type.
This patch prevents cooling device without valid type to be registered.
Signed-off-by: Wei Wang <[email protected]>
---
drivers/thermal/thermal_core.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index d4481cc8958f..974e2d91c30b 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -954,12 +954,22 @@ __thermal_cooling_device_register(struct device_node *np,
struct thermal_zone_device *pos = NULL;
int result;
- if (type && strlen(type) >= THERMAL_NAME_LENGTH)
+ if (!type || !type[0]) {
+ pr_err("Error: No cooling device type defined\n");
return ERR_PTR(-EINVAL);
+ }
+
+ if (strlen(type) >= THERMAL_NAME_LENGTH) {
+ pr_err("Error: Cooling device name over %d chars: %s\n",
+ THERMAL_NAME_LENGTH, type);
+ return ERR_PTR(-EINVAL);
+ }
if (!ops || !ops->get_max_state || !ops->get_cur_state ||
- !ops->set_cur_state)
+ !ops->set_cur_state) {
+ pr_err("Error: Cooling device missing callbacks: %s\n", type);
return ERR_PTR(-EINVAL);
+ }
cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
if (!cdev)
@@ -972,7 +982,7 @@ __thermal_cooling_device_register(struct device_node *np,
}
cdev->id = result;
- strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
+ strlcpy(cdev->type, type, sizeof(cdev->type));
mutex_init(&cdev->lock);
INIT_LIST_HEAD(&cdev->thermal_instances);
cdev->np = np;
--
2.24.0.393.g34dc348eaf-goog
The paths thermal_zone%d and cooling_device%d are not intuitive and the
numbers are subject to change due to device tree change. This usually
leads to tree traversal in userspace code.
The patch creates `tz-by-name' and `cdev-by-name' for thermal zone and
cooling_device respectively.
Signed-off-by: Wei Wang <[email protected]>
Reviewed-by: Amit Kucheria <[email protected]>
---
drivers/thermal/thermal_core.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 9db7f72e70f8..7872bd527f3f 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -22,6 +22,7 @@
#include <net/netlink.h>
#include <net/genetlink.h>
#include <linux/suspend.h>
+#include <linux/kobject.h>
#define CREATE_TRACE_POINTS
#include <trace/events/thermal.h>
@@ -46,6 +47,8 @@ static DEFINE_MUTEX(poweroff_lock);
static atomic_t in_suspend;
static bool power_off_triggered;
+static struct kobject *cdev_link_kobj;
+static struct kobject *tz_link_kobj;
static struct thermal_governor *def_governor;
@@ -999,9 +1002,15 @@ __thermal_cooling_device_register(struct device_node *np,
return ERR_PTR(result);
}
- /* Add 'this' new cdev to the global cdev list */
+ /* Add 'this' new cdev to the global cdev list and create link*/
mutex_lock(&thermal_list_lock);
list_add(&cdev->node, &thermal_cdev_list);
+ if (!cdev_link_kobj)
+ cdev_link_kobj = kobject_create_and_add("cdev-by-name",
+ cdev->device.kobj.parent);
+ if (!cdev_link_kobj || sysfs_create_link(cdev_link_kobj,
+ &cdev->device.kobj, cdev->type))
+ dev_err(&cdev->device, "Failed to create cdev-by-name link\n");
mutex_unlock(&thermal_list_lock);
/* Update binding information for 'this' new cdev */
@@ -1167,6 +1176,8 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
}
}
}
+ if (cdev_link_kobj)
+ sysfs_remove_link(cdev_link_kobj, cdev->type);
mutex_unlock(&thermal_list_lock);
@@ -1354,6 +1365,12 @@ thermal_zone_device_register(const char *type, int trips, int mask,
mutex_lock(&thermal_list_lock);
list_add_tail(&tz->node, &thermal_tz_list);
+ if (!tz_link_kobj)
+ tz_link_kobj = kobject_create_and_add("tz-by-name",
+ tz->device.kobj.parent);
+ if (!tz_link_kobj || sysfs_create_link(tz_link_kobj,
+ &tz->device.kobj, tz->type))
+ dev_err(&tz->device, "Failed to create tz-by-name link\n");
mutex_unlock(&thermal_list_lock);
/* Bind cooling devices for this zone */
@@ -1425,6 +1442,8 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
}
}
}
+ if (tz_link_kobj)
+ sysfs_remove_link(tz_link_kobj, tz->type);
mutex_unlock(&thermal_list_lock);
--
2.24.0.393.g34dc348eaf-goog
Follow up with commit 67eed44b8a8a ("thermal: Add some error messages")
to clean up checkpatch warning on line length and also add more message
for developers.
Signed-off-by: Wei Wang <[email protected]>
---
drivers/thermal/thermal_core.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 974e2d91c30b..9db7f72e70f8 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1255,29 +1255,33 @@ thermal_zone_device_register(const char *type, int trips, int mask,
int count;
struct thermal_governor *governor;
- if (!type || strlen(type) == 0) {
+ if (!type || !type[0]) {
pr_err("Error: No thermal zone type defined\n");
return ERR_PTR(-EINVAL);
}
- if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
- pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n",
- type, THERMAL_NAME_LENGTH);
+ if (strlen(type) >= THERMAL_NAME_LENGTH) {
+ pr_err("Error: Thermal zone name over %d chars: %s\n",
+ THERMAL_NAME_LENGTH, type);
return ERR_PTR(-EINVAL);
}
if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
- pr_err("Error: Incorrect number of thermal trips\n");
+ pr_err("Error: Incorrect number of thermal trips: %s\n", type);
return ERR_PTR(-EINVAL);
}
if (!ops) {
- pr_err("Error: Thermal zone device ops not defined\n");
+ pr_err("Error: Thermal zone device ops not defined: %s\n",
+ type);
return ERR_PTR(-EINVAL);
}
- if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
+ if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp)) {
+ pr_err("Error: Thermal zone device missing callback: %s\n",
+ type);
return ERR_PTR(-EINVAL);
+ }
tz = kzalloc(sizeof(*tz), GFP_KERNEL);
if (!tz)
--
2.24.0.393.g34dc348eaf-goog
On Wed, Dec 04, 2019 at 11:19:53PM -0800, Wei Wang wrote:
> The paths thermal_zone%d and cooling_device%d are not intuitive and the
> numbers are subject to change due to device tree change. This usually
> leads to tree traversal in userspace code.
> The patch creates `tz-by-name' and `cdev-by-name' for thermal zone and
> cooling_device respectively.
This is useful, especially for systems with plenty of thermal zones :)
> Signed-off-by: Wei Wang <[email protected]>
> Reviewed-by: Amit Kucheria <[email protected]>
> ---
> drivers/thermal/thermal_core.c | 21 ++++++++++++++++++++-
> 1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 9db7f72e70f8..7872bd527f3f 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -22,6 +22,7 @@
> #include <net/netlink.h>
> #include <net/genetlink.h>
> #include <linux/suspend.h>
> +#include <linux/kobject.h>
>
> #define CREATE_TRACE_POINTS
> #include <trace/events/thermal.h>
> @@ -46,6 +47,8 @@ static DEFINE_MUTEX(poweroff_lock);
>
> static atomic_t in_suspend;
> static bool power_off_triggered;
> +static struct kobject *cdev_link_kobj;
> +static struct kobject *tz_link_kobj;
>
> static struct thermal_governor *def_governor;
>
> @@ -999,9 +1002,15 @@ __thermal_cooling_device_register(struct device_node *np,
> return ERR_PTR(result);
> }
>
> - /* Add 'this' new cdev to the global cdev list */
> + /* Add 'this' new cdev to the global cdev list and create link*/
> mutex_lock(&thermal_list_lock);
> list_add(&cdev->node, &thermal_cdev_list);
> + if (!cdev_link_kobj)
> + cdev_link_kobj = kobject_create_and_add("cdev-by-name",
> + cdev->device.kobj.parent);
> + if (!cdev_link_kobj || sysfs_create_link(cdev_link_kobj,
> + &cdev->device.kobj, cdev->type))
> + dev_err(&cdev->device, "Failed to create cdev-by-name link\n");
> mutex_unlock(&thermal_list_lock);
>
> /* Update binding information for 'this' new cdev */
> @@ -1167,6 +1176,8 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
> }
> }
> }
> + if (cdev_link_kobj)
> + sysfs_remove_link(cdev_link_kobj, cdev->type);
>
> mutex_unlock(&thermal_list_lock);
>
> @@ -1354,6 +1365,12 @@ thermal_zone_device_register(const char *type, int trips, int mask,
>
> mutex_lock(&thermal_list_lock);
> list_add_tail(&tz->node, &thermal_tz_list);
> + if (!tz_link_kobj)
> + tz_link_kobj = kobject_create_and_add("tz-by-name",
> + tz->device.kobj.parent);
> + if (!tz_link_kobj || sysfs_create_link(tz_link_kobj,
> + &tz->device.kobj, tz->type))
> + dev_err(&tz->device, "Failed to create tz-by-name link\n");
> mutex_unlock(&thermal_list_lock);
>
> /* Bind cooling devices for this zone */
> @@ -1425,6 +1442,8 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
> }
> }
> }
> + if (tz_link_kobj)
> + sysfs_remove_link(tz_link_kobj, tz->type);
>
> mutex_unlock(&thermal_list_lock);
>
Reviewed-by: Matthias Kaehlcke <[email protected]>
Tested-by: Matthias Kaehlcke <[email protected]>
On Thu, Dec 5, 2019 at 12:50 PM Wei Wang <[email protected]> wrote:
>
> commit 54fa38cc2eda ("thermal: core: prevent zones with no types to be
> registered") added logic to prevent thermal zone with empty type to be
> registered. Similarly, there are APIs that rely on cdev->type.
> This patch prevents cooling device without valid type to be registered.
>
> Signed-off-by: Wei Wang <[email protected]>
Looks better now. Thanks.
Reviewed-by: Amit Kucheria <[email protected]>
Tested-by: Amit Kucheria <[email protected]>
> ---
> drivers/thermal/thermal_core.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index d4481cc8958f..974e2d91c30b 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -954,12 +954,22 @@ __thermal_cooling_device_register(struct device_node *np,
> struct thermal_zone_device *pos = NULL;
> int result;
>
> - if (type && strlen(type) >= THERMAL_NAME_LENGTH)
> + if (!type || !type[0]) {
> + pr_err("Error: No cooling device type defined\n");
> return ERR_PTR(-EINVAL);
> + }
> +
> + if (strlen(type) >= THERMAL_NAME_LENGTH) {
> + pr_err("Error: Cooling device name over %d chars: %s\n",
> + THERMAL_NAME_LENGTH, type);
> + return ERR_PTR(-EINVAL);
> + }
>
> if (!ops || !ops->get_max_state || !ops->get_cur_state ||
> - !ops->set_cur_state)
> + !ops->set_cur_state) {
> + pr_err("Error: Cooling device missing callbacks: %s\n", type);
> return ERR_PTR(-EINVAL);
> + }
>
> cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
> if (!cdev)
> @@ -972,7 +982,7 @@ __thermal_cooling_device_register(struct device_node *np,
> }
>
> cdev->id = result;
> - strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
> + strlcpy(cdev->type, type, sizeof(cdev->type));
> mutex_init(&cdev->lock);
> INIT_LIST_HEAD(&cdev->thermal_instances);
> cdev->np = np;
> --
> 2.24.0.393.g34dc348eaf-goog
>
On Thu, Dec 5, 2019 at 12:50 PM Wei Wang <[email protected]> wrote:
>
> Follow up with commit 67eed44b8a8a ("thermal: Add some error messages")
> to clean up checkpatch warning on line length and also add more message
> for developers.
>
> Signed-off-by: Wei Wang <[email protected]>
Reviewed-by: Amit Kucheria <[email protected]>
> ---
> drivers/thermal/thermal_core.c | 18 +++++++++++-------
> 1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 974e2d91c30b..9db7f72e70f8 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -1255,29 +1255,33 @@ thermal_zone_device_register(const char *type, int trips, int mask,
> int count;
> struct thermal_governor *governor;
>
> - if (!type || strlen(type) == 0) {
> + if (!type || !type[0]) {
> pr_err("Error: No thermal zone type defined\n");
> return ERR_PTR(-EINVAL);
> }
>
> - if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
> - pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n",
> - type, THERMAL_NAME_LENGTH);
> + if (strlen(type) >= THERMAL_NAME_LENGTH) {
> + pr_err("Error: Thermal zone name over %d chars: %s\n",
> + THERMAL_NAME_LENGTH, type);
> return ERR_PTR(-EINVAL);
> }
>
> if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
> - pr_err("Error: Incorrect number of thermal trips\n");
> + pr_err("Error: Incorrect number of thermal trips: %s\n", type);
> return ERR_PTR(-EINVAL);
> }
>
> if (!ops) {
> - pr_err("Error: Thermal zone device ops not defined\n");
> + pr_err("Error: Thermal zone device ops not defined: %s\n",
> + type);
> return ERR_PTR(-EINVAL);
> }
>
> - if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
> + if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp)) {
> + pr_err("Error: Thermal zone device missing callback: %s\n",
> + type);
> return ERR_PTR(-EINVAL);
> + }
>
> tz = kzalloc(sizeof(*tz), GFP_KERNEL);
> if (!tz)
> --
> 2.24.0.393.g34dc348eaf-goog
>
On Thu, Dec 5, 2019 at 12:50 PM Wei Wang <[email protected]> wrote:
>
> The paths thermal_zone%d and cooling_device%d are not intuitive and the
> numbers are subject to change due to device tree change. This usually
> leads to tree traversal in userspace code.
> The patch creates `tz-by-name' and `cdev-by-name' for thermal zone and
> cooling_device respectively.
>
> Signed-off-by: Wei Wang <[email protected]>
> Reviewed-by: Amit Kucheria <[email protected]>
Tested-by: Amit Kucheria <[email protected]>
> ---
> drivers/thermal/thermal_core.c | 21 ++++++++++++++++++++-
> 1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 9db7f72e70f8..7872bd527f3f 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -22,6 +22,7 @@
> #include <net/netlink.h>
> #include <net/genetlink.h>
> #include <linux/suspend.h>
> +#include <linux/kobject.h>
>
> #define CREATE_TRACE_POINTS
> #include <trace/events/thermal.h>
> @@ -46,6 +47,8 @@ static DEFINE_MUTEX(poweroff_lock);
>
> static atomic_t in_suspend;
> static bool power_off_triggered;
> +static struct kobject *cdev_link_kobj;
> +static struct kobject *tz_link_kobj;
>
> static struct thermal_governor *def_governor;
>
> @@ -999,9 +1002,15 @@ __thermal_cooling_device_register(struct device_node *np,
> return ERR_PTR(result);
> }
>
> - /* Add 'this' new cdev to the global cdev list */
> + /* Add 'this' new cdev to the global cdev list and create link*/
> mutex_lock(&thermal_list_lock);
> list_add(&cdev->node, &thermal_cdev_list);
> + if (!cdev_link_kobj)
> + cdev_link_kobj = kobject_create_and_add("cdev-by-name",
> + cdev->device.kobj.parent);
> + if (!cdev_link_kobj || sysfs_create_link(cdev_link_kobj,
> + &cdev->device.kobj, cdev->type))
> + dev_err(&cdev->device, "Failed to create cdev-by-name link\n");
> mutex_unlock(&thermal_list_lock);
>
> /* Update binding information for 'this' new cdev */
> @@ -1167,6 +1176,8 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
> }
> }
> }
> + if (cdev_link_kobj)
> + sysfs_remove_link(cdev_link_kobj, cdev->type);
>
> mutex_unlock(&thermal_list_lock);
>
> @@ -1354,6 +1365,12 @@ thermal_zone_device_register(const char *type, int trips, int mask,
>
> mutex_lock(&thermal_list_lock);
> list_add_tail(&tz->node, &thermal_tz_list);
> + if (!tz_link_kobj)
> + tz_link_kobj = kobject_create_and_add("tz-by-name",
> + tz->device.kobj.parent);
> + if (!tz_link_kobj || sysfs_create_link(tz_link_kobj,
> + &tz->device.kobj, tz->type))
> + dev_err(&tz->device, "Failed to create tz-by-name link\n");
> mutex_unlock(&thermal_list_lock);
>
> /* Bind cooling devices for this zone */
> @@ -1425,6 +1442,8 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
> }
> }
> }
> + if (tz_link_kobj)
> + sysfs_remove_link(tz_link_kobj, tz->type);
>
> mutex_unlock(&thermal_list_lock);
>
> --
> 2.24.0.393.g34dc348eaf-goog
>
On Sun, Dec 8, 2019 at 11:41 PM Amit Kucheria
<[email protected]> wrote:
>
> On Thu, Dec 5, 2019 at 12:50 PM Wei Wang <[email protected]> wrote:
> >
> > commit 54fa38cc2eda ("thermal: core: prevent zones with no types to be
> > registered") added logic to prevent thermal zone with empty type to be
> > registered. Similarly, there are APIs that rely on cdev->type.
> > This patch prevents cooling device without valid type to be registered.
> >
> > Signed-off-by: Wei Wang <[email protected]>
>
> Looks better now. Thanks.
>
Thanks Amit for the review and testing.
> Reviewed-by: Amit Kucheria <[email protected]>
> Tested-by: Amit Kucheria <[email protected]>
>
> > ---
> > drivers/thermal/thermal_core.c | 16 +++++++++++++---
> > 1 file changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> > index d4481cc8958f..974e2d91c30b 100644
> > --- a/drivers/thermal/thermal_core.c
> > +++ b/drivers/thermal/thermal_core.c
> > @@ -954,12 +954,22 @@ __thermal_cooling_device_register(struct device_node *np,
> > struct thermal_zone_device *pos = NULL;
> > int result;
> >
> > - if (type && strlen(type) >= THERMAL_NAME_LENGTH)
> > + if (!type || !type[0]) {
> > + pr_err("Error: No cooling device type defined\n");
> > return ERR_PTR(-EINVAL);
> > + }
> > +
> > + if (strlen(type) >= THERMAL_NAME_LENGTH) {
> > + pr_err("Error: Cooling device name over %d chars: %s\n",
> > + THERMAL_NAME_LENGTH, type);
> > + return ERR_PTR(-EINVAL);
> > + }
> >
> > if (!ops || !ops->get_max_state || !ops->get_cur_state ||
> > - !ops->set_cur_state)
> > + !ops->set_cur_state) {
> > + pr_err("Error: Cooling device missing callbacks: %s\n", type);
> > return ERR_PTR(-EINVAL);
> > + }
> >
> > cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
> > if (!cdev)
> > @@ -972,7 +982,7 @@ __thermal_cooling_device_register(struct device_node *np,
> > }
> >
> > cdev->id = result;
> > - strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
> > + strlcpy(cdev->type, type, sizeof(cdev->type));
> > mutex_init(&cdev->lock);
> > INIT_LIST_HEAD(&cdev->thermal_instances);
> > cdev->np = np;
> > --
> > 2.24.0.393.g34dc348eaf-goog
> >
On 05/12/2019 08:19, Wei Wang wrote:
> commit 54fa38cc2eda ("thermal: core: prevent zones with no types to be
> registered") added logic to prevent thermal zone with empty type to be
> registered. Similarly, there are APIs that rely on cdev->type.
> This patch prevents cooling device without valid type to be registered.
>
> Signed-off-by: Wei Wang <[email protected]>
> ---
> drivers/thermal/thermal_core.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index d4481cc8958f..974e2d91c30b 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -954,12 +954,22 @@ __thermal_cooling_device_register(struct device_node *np,
> struct thermal_zone_device *pos = NULL;
> int result;
>
> - if (type && strlen(type) >= THERMAL_NAME_LENGTH)
> + if (!type || !type[0]) {
Why not use strlen(type) == 0 ?
> + pr_err("Error: No cooling device type defined\n");
> return ERR_PTR(-EINVAL);
> + }
> +
> + if (strlen(type) >= THERMAL_NAME_LENGTH) {
> + pr_err("Error: Cooling device name over %d chars: %s\n",
> + THERMAL_NAME_LENGTH, type);
> + return ERR_PTR(-EINVAL);
> + }
>
> if (!ops || !ops->get_max_state || !ops->get_cur_state ||
> - !ops->set_cur_state)
> + !ops->set_cur_state) {
> + pr_err("Error: Cooling device missing callbacks: %s\n", type);
> return ERR_PTR(-EINVAL);
> + }
>
> cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
> if (!cdev)
> @@ -972,7 +982,7 @@ __thermal_cooling_device_register(struct device_node *np,
> }
>
> cdev->id = result;
> - strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
> + strlcpy(cdev->type, type, sizeof(cdev->type));
> mutex_init(&cdev->lock);
> INIT_LIST_HEAD(&cdev->thermal_instances);
> cdev->np = np;
>
--
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On Mon, Dec 9, 2019 at 11:36 AM Daniel Lezcano
<[email protected]> wrote:
>
> On 05/12/2019 08:19, Wei Wang wrote:
> > commit 54fa38cc2eda ("thermal: core: prevent zones with no types to be
> > registered") added logic to prevent thermal zone with empty type to be
> > registered. Similarly, there are APIs that rely on cdev->type.
> > This patch prevents cooling device without valid type to be registered.
> >
> > Signed-off-by: Wei Wang <[email protected]>
> > ---
> > drivers/thermal/thermal_core.c | 16 +++++++++++++---
> > 1 file changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> > index d4481cc8958f..974e2d91c30b 100644
> > --- a/drivers/thermal/thermal_core.c
> > +++ b/drivers/thermal/thermal_core.c
> > @@ -954,12 +954,22 @@ __thermal_cooling_device_register(struct device_node *np,
> > struct thermal_zone_device *pos = NULL;
> > int result;
> >
> > - if (type && strlen(type) >= THERMAL_NAME_LENGTH)
> > + if (!type || !type[0]) {
>
> Why not use strlen(type) == 0 ?
Checking empty is faster than getting length and this is already a
pattern used in this file:
https://github.com/torvalds/linux/blob/v5.4/drivers/thermal/thermal_core.c#L63
>
> > + pr_err("Error: No cooling device type defined\n");
> > return ERR_PTR(-EINVAL);
> > + }
> > +
> > + if (strlen(type) >= THERMAL_NAME_LENGTH) {
> > + pr_err("Error: Cooling device name over %d chars: %s\n",
> > + THERMAL_NAME_LENGTH, type);
> > + return ERR_PTR(-EINVAL);
> > + }
> >
> > if (!ops || !ops->get_max_state || !ops->get_cur_state ||
> > - !ops->set_cur_state)
> > + !ops->set_cur_state) {
> > + pr_err("Error: Cooling device missing callbacks: %s\n", type);
> > return ERR_PTR(-EINVAL);
> > + }
> >
> > cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
> > if (!cdev)
> > @@ -972,7 +982,7 @@ __thermal_cooling_device_register(struct device_node *np,
> > }
> >
> > cdev->id = result;
> > - strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
> > + strlcpy(cdev->type, type, sizeof(cdev->type));
> > mutex_init(&cdev->lock);
> > INIT_LIST_HEAD(&cdev->thermal_instances);
> > cdev->np = np;
> >
>
>
> --
> <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
>
On 05/12/2019 08:19, Wei Wang wrote:
> The paths thermal_zone%d and cooling_device%d are not intuitive and the
> numbers are subject to change due to device tree change. This usually
> leads to tree traversal in userspace code.
> The patch creates `tz-by-name' and `cdev-by-name' for thermal zone and
> cooling_device respectively.
Instead of adding another ABI, I suggest we put the current one
deprecated with a warning in the dmesg, update the documentation and
change the name the next version.
> Changes since v1 [1]:
> * Split cooling device registration into a seperate patch
> Changes since v2 [2]:
> * Split improve error message in thermal zone registration
>
> [1]: v1: https://lore.kernel.org/patchwork/patch/1139450/
> [2]: v2: https://lkml.org/lkml/2019/12/4/1291
>
> Wei Wang (3):
> thermal: prevent cooling device with no type to be registered
> thermal: improve error message in thermal zone registration
> thermal: create softlink by name for thermal_zone and cooling_device
>
> drivers/thermal/thermal_core.c | 55 +++++++++++++++++++++++++++-------
> 1 file changed, 44 insertions(+), 11 deletions(-)
>
--
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On Tue, Dec 10, 2019 at 6:36 AM Daniel Lezcano
<[email protected]> wrote:
>
> On 05/12/2019 08:19, Wei Wang wrote:
> > The paths thermal_zone%d and cooling_device%d are not intuitive and the
> > numbers are subject to change due to device tree change. This usually
> > leads to tree traversal in userspace code.
> > The patch creates `tz-by-name' and `cdev-by-name' for thermal zone and
> > cooling_device respectively.
>
> Instead of adding another ABI, I suggest we put the current one
> deprecated with a warning in the dmesg, update the documentation and
> change the name the next version.
>
>
IMHO, we should keep the existing path which is a common pattern for
sysfs interface. There are reasons we need couple thermal zone and
cooling device in one class, but might be worth considering split as
the latter might be used for other purposes e.g. battery current limit
for preventive vdrop prevention. By nature, thermal zone are sensors,
and cooling devices are usually components with potential high power
use.
> > Changes since v1 [1]:
> > * Split cooling device registration into a seperate patch
> > Changes since v2 [2]:
> > * Split improve error message in thermal zone registration
> >
> > [1]: v1: https://lore.kernel.org/patchwork/patch/1139450/
> > [2]: v2: https://lkml.org/lkml/2019/12/4/1291
> >
> > Wei Wang (3):
> > thermal: prevent cooling device with no type to be registered
> > thermal: improve error message in thermal zone registration
> > thermal: create softlink by name for thermal_zone and cooling_device
> >
> > drivers/thermal/thermal_core.c | 55 +++++++++++++++++++++++++++-------
> > 1 file changed, 44 insertions(+), 11 deletions(-)
> >
>
>
> --
> <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
>
On 10/12/2019 21:01, Wei Wang wrote:
> On Tue, Dec 10, 2019 at 6:36 AM Daniel Lezcano
> <[email protected]> wrote:
>>
>> On 05/12/2019 08:19, Wei Wang wrote:
>>> The paths thermal_zone%d and cooling_device%d are not intuitive and the
>>> numbers are subject to change due to device tree change. This usually
>>> leads to tree traversal in userspace code.
>>> The patch creates `tz-by-name' and `cdev-by-name' for thermal zone and
>>> cooling_device respectively.
>>
>> Instead of adding another ABI, I suggest we put the current one
>> deprecated with a warning in the dmesg, update the documentation and
>> change the name the next version.
>>
>>
>
> IMHO, we should keep the existing path which is a common pattern for
> sysfs interface. There are reasons we need couple thermal zone and
> cooling device in one class, but might be worth considering split as
> the latter might be used for other purposes e.g. battery current limit
> for preventive vdrop prevention. By nature, thermal zone are sensors,
> and cooling devices are usually components with potential high power
> use.
[Added Greghk and Rafael in Cc]
I understand but I would like to have Greg's and Rafael's opinion on that.
The result is:
ls -al /sys/devices/virtual/thermal/
total 0
drwxr-xr-x 22 root root 0 Dec 10 12:34 .
drwxr-xr-x 15 root root 0 Dec 10 12:34 ..
drwxr-xr-x 2 root root 0 Dec 10 13:18 cdev-by-name
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device0
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device1
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device10
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device11
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device12
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device13
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device14
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device15
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device2
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device3
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device4
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device5
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device6
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device7
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device8
drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device9
drwxr-xr-x 3 root root 0 Dec 10 12:34 thermal_zone0
drwxr-xr-x 3 root root 0 Dec 10 12:34 thermal_zone1
drwxr-xr-x 2 root root 0 Dec 10 13:18 tz-by-name
ls -al /sys/devices/virtual/thermal/cdev-by-name/
total 0
drwxr-xr-x 2 root root 0 Dec 10 13:18 .
drwxr-xr-x 22 root root 0 Dec 10 12:34 ..
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-cpufreq-0 ->
../cooling_device0
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-cpufreq-1 ->
../cooling_device1
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-0 -> ../cooling_device2
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-1 -> ../cooling_device3
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-10 ->
../cooling_device12
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-11 ->
../cooling_device13
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-12 ->
../cooling_device14
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-13 ->
../cooling_device15
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-2 -> ../cooling_device4
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-3 -> ../cooling_device5
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-4 -> ../cooling_device6
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-5 -> ../cooling_device7
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-6 -> ../cooling_device8
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-7 -> ../cooling_device9
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-8 -> ../cooling_device10
lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-idle-9 -> ../cooling_device11
ls -al /sys/devices/virtual/thermal/tz-by-name/
total 0
drwxr-xr-x 2 root root 0 Dec 10 13:18 .
drwxr-xr-x 22 root root 0 Dec 10 12:34 ..
lrwxrwxrwx 1 root root 0 Dec 10 20:53 cpu -> ../thermal_zone0
lrwxrwxrwx 1 root root 0 Dec 10 20:53 gpu -> ../thermal_zone1
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On Tue, Dec 10, 2019 at 09:54:11PM +0100, Daniel Lezcano wrote:
> On 10/12/2019 21:01, Wei Wang wrote:
> > On Tue, Dec 10, 2019 at 6:36 AM Daniel Lezcano
> > <[email protected]> wrote:
> >>
> >> On 05/12/2019 08:19, Wei Wang wrote:
> >>> The paths thermal_zone%d and cooling_device%d are not intuitive and the
> >>> numbers are subject to change due to device tree change. This usually
> >>> leads to tree traversal in userspace code.
> >>> The patch creates `tz-by-name' and `cdev-by-name' for thermal zone and
> >>> cooling_device respectively.
> >>
> >> Instead of adding another ABI, I suggest we put the current one
> >> deprecated with a warning in the dmesg, update the documentation and
> >> change the name the next version.
> >>
> >>
> >
> > IMHO, we should keep the existing path which is a common pattern for
> > sysfs interface. There are reasons we need couple thermal zone and
> > cooling device in one class, but might be worth considering split as
> > the latter might be used for other purposes e.g. battery current limit
> > for preventive vdrop prevention. By nature, thermal zone are sensors,
> > and cooling devices are usually components with potential high power
> > use.
>
> [Added Greghk and Rafael in Cc]
>
> I understand but I would like to have Greg's and Rafael's opinion on that.
>
> The result is:
>
> ls -al /sys/devices/virtual/thermal/
> total 0
> drwxr-xr-x 22 root root 0 Dec 10 12:34 .
> drwxr-xr-x 15 root root 0 Dec 10 12:34 ..
> drwxr-xr-x 2 root root 0 Dec 10 13:18 cdev-by-name
Ick!
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device0
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device1
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device10
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device11
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device12
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device13
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device14
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device15
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device2
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device3
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device4
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device5
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device6
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device7
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device8
> drwxr-xr-x 3 root root 0 Dec 10 12:34 cooling_device9
> drwxr-xr-x 3 root root 0 Dec 10 12:34 thermal_zone0
> drwxr-xr-x 3 root root 0 Dec 10 12:34 thermal_zone1
> drwxr-xr-x 2 root root 0 Dec 10 13:18 tz-by-name
>
> ls -al /sys/devices/virtual/thermal/cdev-by-name/
> total 0
> drwxr-xr-x 2 root root 0 Dec 10 13:18 .
> drwxr-xr-x 22 root root 0 Dec 10 12:34 ..
> lrwxrwxrwx 1 root root 0 Dec 10 13:18 thermal-cpufreq-0 ->
> ../cooling_device0
Ick ick ick!
What is this all for?
Where is the Documentation/ABI/ entry trying to explain this mess?
Please provide that and we can go from there as I have no idea what this
is trying to "help with".
thanks,
greg k-h
On Tue, Dec 10, 2019 at 09:54:11PM +0100, Daniel Lezcano wrote:
> On 10/12/2019 21:01, Wei Wang wrote:
> > On Tue, Dec 10, 2019 at 6:36 AM Daniel Lezcano
> > <[email protected]> wrote:
> >>
> >> On 05/12/2019 08:19, Wei Wang wrote:
> >>> The paths thermal_zone%d and cooling_device%d are not intuitive and the
> >>> numbers are subject to change due to device tree change. This usually
> >>> leads to tree traversal in userspace code.
tree traversal is supposed to be done in userspace code :)
But what userspace code needs to do this, and for what?
thanks,
greg k-h
On Wed, Dec 11, 2019 at 12:54 AM Greg Kroah-Hartman
<[email protected]> wrote:
>
> On Tue, Dec 10, 2019 at 09:54:11PM +0100, Daniel Lezcano wrote:
> > On 10/12/2019 21:01, Wei Wang wrote:
> > > On Tue, Dec 10, 2019 at 6:36 AM Daniel Lezcano
> > > <[email protected]> wrote:
> > >>
> > >> On 05/12/2019 08:19, Wei Wang wrote:
> > >>> The paths thermal_zone%d and cooling_device%d are not intuitive and the
> > >>> numbers are subject to change due to device tree change. This usually
> > >>> leads to tree traversal in userspace code.
>
> tree traversal is supposed to be done in userspace code :)
>
Yes, that can be done in userspace, but given the amount of thermal
zones we have in some mobile devices, this will bring a lot of
convenience.
e.g. this is on Pixel 4 XL:
coral:/ # ls /sys/devices/virtual/thermal/
cdev-by-name cooling_device15 cooling_device22 cooling_device3
cooling_device9 thermal_zone15 thermal_zone22 thermal_zone3
thermal_zone37 thermal_zone44 thermal_zone51 thermal_zone59
thermal_zone66 thermal_zone73 thermal_zone80 thermal_zone88
cooling_device0 cooling_device16 cooling_device23 cooling_device30
thermal_zone0 thermal_zone16 thermal_zone23 thermal_zone30
thermal_zone38 thermal_zone45 thermal_zone52 thermal_zone6
thermal_zone67 thermal_zone74 thermal_zone81 thermal_zone9
cooling_device1 cooling_device17 cooling_device24 cooling_device31
thermal_zone1 thermal_zone17 thermal_zone24 thermal_zone31
thermal_zone39 thermal_zone46 thermal_zone53 thermal_zone60
thermal_zone68 thermal_zone75 thermal_zone82 tz-by-name
cooling_device10 cooling_device18 cooling_device25 cooling_device4
thermal_zone10 thermal_zone18 thermal_zone25 thermal_zone32
thermal_zone4 thermal_zone47 thermal_zone54 thermal_zone61
thermal_zone69 thermal_zone76 thermal_zone83
cooling_device11 cooling_device19 cooling_device26 cooling_device5
thermal_zone11 thermal_zone19 thermal_zone26 thermal_zone33
thermal_zone40 thermal_zone48 thermal_zone55 thermal_zone62
thermal_zone7 thermal_zone77 thermal_zone84
cooling_device12 cooling_device2 cooling_device27 cooling_device6
thermal_zone12 thermal_zone2 thermal_zone27 thermal_zone34
thermal_zone41 thermal_zone49 thermal_zone56 thermal_zone63
thermal_zone70 thermal_zone78 thermal_zone85
cooling_device13 cooling_device20 cooling_device28 cooling_device7
thermal_zone13 thermal_zone20 thermal_zone28 thermal_zone35
thermal_zone42 thermal_zone5 thermal_zone57 thermal_zone64
thermal_zone71 thermal_zone79 thermal_zone86
cooling_device14 cooling_device21 cooling_device29 cooling_device8
thermal_zone14 thermal_zone21 thermal_zone29 thermal_zone36
thermal_zone43 thermal_zone50 thermal_zone58 thermal_zone65
thermal_zone72 thermal_zone8 thermal_zone87
> But what userspace code needs to do this, and for what?
In Android, thermal daemon and thermal HAL as well as some init.rc
script would use those thermal paths for managing and monitoring
thermal. The daemon/HAL could have logic pipled in, however Android's
init.rc script would be really tricky.
On a related note, we also create /dev/block/by-name links from userspace.
Thanks!
-Wei
>
> thanks,
>
> greg k-h
On 11/12/2019 21:11, Wei Wang wrote:
> On Wed, Dec 11, 2019 at 12:54 AM Greg Kroah-Hartman
> <[email protected]> wrote:
>>
>> On Tue, Dec 10, 2019 at 09:54:11PM +0100, Daniel Lezcano wrote:
>>> On 10/12/2019 21:01, Wei Wang wrote:
>>>> On Tue, Dec 10, 2019 at 6:36 AM Daniel Lezcano
>>>> <[email protected]> wrote:
>>>>>
>>>>> On 05/12/2019 08:19, Wei Wang wrote:
>>>>>> The paths thermal_zone%d and cooling_device%d are not intuitive and the
>>>>>> numbers are subject to change due to device tree change. This usually
>>>>>> leads to tree traversal in userspace code.
>>
>> tree traversal is supposed to be done in userspace code :)
>>
> Yes, that can be done in userspace, but given the amount of thermal
> zones we have in some mobile devices, this will bring a lot of
> convenience.
But usually all these thermal zones are fixed and building the name<->tz
association is just a question of a few lines of code from userspace,
no? What would be the benefit of adding more ABI?
If there is a thermal zone change, then a notification can be used, so
the userspace code rebuild the name<->tz, no?
> e.g. this is on Pixel 4 XL:
> coral:/ # ls /sys/devices/virtual/thermal/
> cdev-by-name cooling_device15 cooling_device22 cooling_device3
> cooling_device9 thermal_zone15 thermal_zone22 thermal_zone3
> thermal_zone37 thermal_zone44 thermal_zone51 thermal_zone59
> thermal_zone66 thermal_zone73 thermal_zone80 thermal_zone88
> cooling_device0 cooling_device16 cooling_device23 cooling_device30
> thermal_zone0 thermal_zone16 thermal_zone23 thermal_zone30
> thermal_zone38 thermal_zone45 thermal_zone52 thermal_zone6
> thermal_zone67 thermal_zone74 thermal_zone81 thermal_zone9
> cooling_device1 cooling_device17 cooling_device24 cooling_device31
> thermal_zone1 thermal_zone17 thermal_zone24 thermal_zone31
> thermal_zone39 thermal_zone46 thermal_zone53 thermal_zone60
> thermal_zone68 thermal_zone75 thermal_zone82 tz-by-name
> cooling_device10 cooling_device18 cooling_device25 cooling_device4
> thermal_zone10 thermal_zone18 thermal_zone25 thermal_zone32
> thermal_zone4 thermal_zone47 thermal_zone54 thermal_zone61
> thermal_zone69 thermal_zone76 thermal_zone83
> cooling_device11 cooling_device19 cooling_device26 cooling_device5
> thermal_zone11 thermal_zone19 thermal_zone26 thermal_zone33
> thermal_zone40 thermal_zone48 thermal_zone55 thermal_zone62
> thermal_zone7 thermal_zone77 thermal_zone84
> cooling_device12 cooling_device2 cooling_device27 cooling_device6
> thermal_zone12 thermal_zone2 thermal_zone27 thermal_zone34
> thermal_zone41 thermal_zone49 thermal_zone56 thermal_zone63
> thermal_zone70 thermal_zone78 thermal_zone85
> cooling_device13 cooling_device20 cooling_device28 cooling_device7
> thermal_zone13 thermal_zone20 thermal_zone28 thermal_zone35
> thermal_zone42 thermal_zone5 thermal_zone57 thermal_zone64
> thermal_zone71 thermal_zone79 thermal_zone86
> cooling_device14 cooling_device21 cooling_device29 cooling_device8
> thermal_zone14 thermal_zone21 thermal_zone29 thermal_zone36
> thermal_zone43 thermal_zone50 thermal_zone58 thermal_zone65
> thermal_zone72 thermal_zone8 thermal_zone87
>
>
>> But what userspace code needs to do this, and for what?
> In Android, thermal daemon and thermal HAL as well as some init.rc
> script would use those thermal paths for managing and monitoring
> thermal. The daemon/HAL could have logic pipled in, however Android's
> init.rc script would be really tricky.
> On a related note, we also create /dev/block/by-name links from userspace.
>
> Thanks!
> -Wei
>>
>> thanks,
>>
>> greg k-h
--
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On Wed, Dec 11, 2019 at 1:11 PM Daniel Lezcano
<[email protected]> wrote:
>
> On 11/12/2019 21:11, Wei Wang wrote:
> > On Wed, Dec 11, 2019 at 12:54 AM Greg Kroah-Hartman
> > <[email protected]> wrote:
> >>
> >> On Tue, Dec 10, 2019 at 09:54:11PM +0100, Daniel Lezcano wrote:
> >>> On 10/12/2019 21:01, Wei Wang wrote:
> >>>> On Tue, Dec 10, 2019 at 6:36 AM Daniel Lezcano
> >>>> <[email protected]> wrote:
> >>>>>
> >>>>> On 05/12/2019 08:19, Wei Wang wrote:
> >>>>>> The paths thermal_zone%d and cooling_device%d are not intuitive and the
> >>>>>> numbers are subject to change due to device tree change. This usually
> >>>>>> leads to tree traversal in userspace code.
> >>
> >> tree traversal is supposed to be done in userspace code :)
> >>
> > Yes, that can be done in userspace, but given the amount of thermal
> > zones we have in some mobile devices, this will bring a lot of
> > convenience.
>
> But usually all these thermal zones are fixed and building the name<->tz
> association is just a question of a few lines of code from userspace,
> no? What would be the benefit of adding more ABI?
code reuse as tz mapping is per device tree setup and we try to use
the same _type_ in thermal zone in shared client code for Android
thermal API.
>
> If there is a thermal zone change, then a notification can be used, so
> the userspace code rebuild the name<->tz, no?
Assuming you meant for type<->tz, this mapping won't change in runtime
in our case (not unloading things), but it could be changed due to
device tree change, e.g. adding/removing thermal zones.
>
> > e.g. this is on Pixel 4 XL:
> > coral:/ # ls /sys/devices/virtual/thermal/
> > cdev-by-name cooling_device15 cooling_device22 cooling_device3
> > cooling_device9 thermal_zone15 thermal_zone22 thermal_zone3
> > thermal_zone37 thermal_zone44 thermal_zone51 thermal_zone59
> > thermal_zone66 thermal_zone73 thermal_zone80 thermal_zone88
> > cooling_device0 cooling_device16 cooling_device23 cooling_device30
> > thermal_zone0 thermal_zone16 thermal_zone23 thermal_zone30
> > thermal_zone38 thermal_zone45 thermal_zone52 thermal_zone6
> > thermal_zone67 thermal_zone74 thermal_zone81 thermal_zone9
> > cooling_device1 cooling_device17 cooling_device24 cooling_device31
> > thermal_zone1 thermal_zone17 thermal_zone24 thermal_zone31
> > thermal_zone39 thermal_zone46 thermal_zone53 thermal_zone60
> > thermal_zone68 thermal_zone75 thermal_zone82 tz-by-name
> > cooling_device10 cooling_device18 cooling_device25 cooling_device4
> > thermal_zone10 thermal_zone18 thermal_zone25 thermal_zone32
> > thermal_zone4 thermal_zone47 thermal_zone54 thermal_zone61
> > thermal_zone69 thermal_zone76 thermal_zone83
> > cooling_device11 cooling_device19 cooling_device26 cooling_device5
> > thermal_zone11 thermal_zone19 thermal_zone26 thermal_zone33
> > thermal_zone40 thermal_zone48 thermal_zone55 thermal_zone62
> > thermal_zone7 thermal_zone77 thermal_zone84
> > cooling_device12 cooling_device2 cooling_device27 cooling_device6
> > thermal_zone12 thermal_zone2 thermal_zone27 thermal_zone34
> > thermal_zone41 thermal_zone49 thermal_zone56 thermal_zone63
> > thermal_zone70 thermal_zone78 thermal_zone85
> > cooling_device13 cooling_device20 cooling_device28 cooling_device7
> > thermal_zone13 thermal_zone20 thermal_zone28 thermal_zone35
> > thermal_zone42 thermal_zone5 thermal_zone57 thermal_zone64
> > thermal_zone71 thermal_zone79 thermal_zone86
> > cooling_device14 cooling_device21 cooling_device29 cooling_device8
> > thermal_zone14 thermal_zone21 thermal_zone29 thermal_zone36
> > thermal_zone43 thermal_zone50 thermal_zone58 thermal_zone65
> > thermal_zone72 thermal_zone8 thermal_zone87
> >
> >
> >> But what userspace code needs to do this, and for what?
> > In Android, thermal daemon and thermal HAL as well as some init.rc
> > script would use those thermal paths for managing and monitoring
> > thermal. The daemon/HAL could have logic pipled in, however Android's
> > init.rc script would be really tricky.
> > On a related note, we also create /dev/block/by-name links from userspace.
> >
> > Thanks!
> > -Wei
> >>
> >> thanks,
> >>
> >> greg k-h
>
>
> --
> <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
>
On Wed, Dec 11, 2019 at 12:11:53PM -0800, Wei Wang wrote:
> On Wed, Dec 11, 2019 at 12:54 AM Greg Kroah-Hartman
> <[email protected]> wrote:
> >
> > On Tue, Dec 10, 2019 at 09:54:11PM +0100, Daniel Lezcano wrote:
> > > On 10/12/2019 21:01, Wei Wang wrote:
> > > > On Tue, Dec 10, 2019 at 6:36 AM Daniel Lezcano
> > > > <[email protected]> wrote:
> > > >>
> > > >> On 05/12/2019 08:19, Wei Wang wrote:
> > > >>> The paths thermal_zone%d and cooling_device%d are not intuitive and the
> > > >>> numbers are subject to change due to device tree change. This usually
> > > >>> leads to tree traversal in userspace code.
> >
> > tree traversal is supposed to be done in userspace code :)
> >
> Yes, that can be done in userspace, but given the amount of thermal
> zones we have in some mobile devices, this will bring a lot of
> convenience.
Userspace is easier to write than kernel code. Kernel code and apis you
have to retain for the next 20+ years, are you willing to do that?
> e.g. this is on Pixel 4 XL:
> coral:/ # ls /sys/devices/virtual/thermal/
> cdev-by-name cooling_device15 cooling_device22 cooling_device3
> cooling_device9 thermal_zone15 thermal_zone22 thermal_zone3
> thermal_zone37 thermal_zone44 thermal_zone51 thermal_zone59
> thermal_zone66 thermal_zone73 thermal_zone80 thermal_zone88
> cooling_device0 cooling_device16 cooling_device23 cooling_device30
> thermal_zone0 thermal_zone16 thermal_zone23 thermal_zone30
> thermal_zone38 thermal_zone45 thermal_zone52 thermal_zone6
> thermal_zone67 thermal_zone74 thermal_zone81 thermal_zone9
> cooling_device1 cooling_device17 cooling_device24 cooling_device31
> thermal_zone1 thermal_zone17 thermal_zone24 thermal_zone31
> thermal_zone39 thermal_zone46 thermal_zone53 thermal_zone60
> thermal_zone68 thermal_zone75 thermal_zone82 tz-by-name
> cooling_device10 cooling_device18 cooling_device25 cooling_device4
> thermal_zone10 thermal_zone18 thermal_zone25 thermal_zone32
> thermal_zone4 thermal_zone47 thermal_zone54 thermal_zone61
> thermal_zone69 thermal_zone76 thermal_zone83
> cooling_device11 cooling_device19 cooling_device26 cooling_device5
> thermal_zone11 thermal_zone19 thermal_zone26 thermal_zone33
> thermal_zone40 thermal_zone48 thermal_zone55 thermal_zone62
> thermal_zone7 thermal_zone77 thermal_zone84
> cooling_device12 cooling_device2 cooling_device27 cooling_device6
> thermal_zone12 thermal_zone2 thermal_zone27 thermal_zone34
> thermal_zone41 thermal_zone49 thermal_zone56 thermal_zone63
> thermal_zone70 thermal_zone78 thermal_zone85
> cooling_device13 cooling_device20 cooling_device28 cooling_device7
> thermal_zone13 thermal_zone20 thermal_zone28 thermal_zone35
> thermal_zone42 thermal_zone5 thermal_zone57 thermal_zone64
> thermal_zone71 thermal_zone79 thermal_zone86
> cooling_device14 cooling_device21 cooling_device29 cooling_device8
> thermal_zone14 thermal_zone21 thermal_zone29 thermal_zone36
> thermal_zone43 thermal_zone50 thermal_zone58 thermal_zone65
> thermal_zone72 thermal_zone8 thermal_zone87
Nice, you have a crazy SoC here, good luck! :)
> > But what userspace code needs to do this, and for what?
> In Android, thermal daemon and thermal HAL as well as some init.rc
> script would use those thermal paths for managing and monitoring
> thermal. The daemon/HAL could have logic pipled in, however Android's
> init.rc script would be really tricky.
Then put that logic in your userspace code.
> On a related note, we also create /dev/block/by-name links from userspace.
Yes we do, from userspace, not from within the kernel itself, so I think
you have answered the question :)
thanks,
greg k-h
Hi Wei,
(resending because I accidentally replied only to you. Also adding everyone
else back in the thread, not sure what happened before).
On Wed, Dec 11, 2019 at 02:19:03PM -0800, Wei Wang wrote:
> On Wed, Dec 11, 2019 at 1:11 PM Daniel Lezcano
> <[email protected]> wrote:
> >
> > On 11/12/2019 21:11, Wei Wang wrote:
> > > On Wed, Dec 11, 2019 at 12:54 AM Greg Kroah-Hartman
> > > <[email protected]> wrote:
> > >>
> > >> On Tue, Dec 10, 2019 at 09:54:11PM +0100, Daniel Lezcano wrote:
> > >>> On 10/12/2019 21:01, Wei Wang wrote:
> > >>>> On Tue, Dec 10, 2019 at 6:36 AM Daniel Lezcano
> > >>>> <[email protected]> wrote:
> > >>>>>
> > >>>>> On 05/12/2019 08:19, Wei Wang wrote:
> > >>>>>> The paths thermal_zone%d and cooling_device%d are not intuitive and the
> > >>>>>> numbers are subject to change due to device tree change. This usually
> > >>>>>> leads to tree traversal in userspace code.
> > >>
> > >> tree traversal is supposed to be done in userspace code :)
> > >>
> > > Yes, that can be done in userspace, but given the amount of thermal
> > > zones we have in some mobile devices, this will bring a lot of
> > > convenience.
> >
> > But usually all these thermal zones are fixed and building the name<->tz
> > association is just a question of a few lines of code from userspace,
> > no? What would be the benefit of adding more ABI?
>
>
> code reuse as tz mapping is per device tree setup and we try to use
> the same _type_ in thermal zone in shared client code for Android
> thermal API.
CMIIW, but the tz mapping today can still be done by parsing through the
directory the other way? (i.e. tz->type) instead of type->tz?
Also, I understand the resistance to add a new ABI since it will have to be
kept around forever. What would be worth knowing is if these mappings are
static (built once) or you have to go through and parse the directories every
time? AFAIU, the parsing (map creation) seems to only happen once during
boot, so we (Android) should be ok?
>
> >
> > If there is a thermal zone change, then a notification can be used, so
> > the userspace code rebuild the name<->tz, no?
>
>
> Assuming you meant for type<->tz, this mapping won't change in runtime
> in our case (not unloading things), but it could be changed due to
> device tree change, e.g. adding/removing thermal zones.
I actually think we might need this after all. This assumes all tz devices
are registered when userspace (thermal hal/daemon) is coming up. However,
that may soon not be the case and we have to adjust for devices being added
in parallel with userspace?
So, may be we need to start monitoring uevents like we do for power supplies
too? In that case, the mapping can also be done dynamically.
Lastly, I think we can make a case further if there are benefits we can share
here other than convenience. Like startup time, handing hardware variations
etc? (Also point to the current userspace code that uses this)
- ssp
>
>
> >
> > > e.g. this is on Pixel 4 XL:
> > > coral:/ # ls /sys/devices/virtual/thermal/
> > > cdev-by-name cooling_device15 cooling_device22 cooling_device3
> > > cooling_device9 thermal_zone15 thermal_zone22 thermal_zone3
> > > thermal_zone37 thermal_zone44 thermal_zone51 thermal_zone59
> > > thermal_zone66 thermal_zone73 thermal_zone80 thermal_zone88
> > > cooling_device0 cooling_device16 cooling_device23 cooling_device30
> > > thermal_zone0 thermal_zone16 thermal_zone23 thermal_zone30
> > > thermal_zone38 thermal_zone45 thermal_zone52 thermal_zone6
> > > thermal_zone67 thermal_zone74 thermal_zone81 thermal_zone9
> > > cooling_device1 cooling_device17 cooling_device24 cooling_device31
> > > thermal_zone1 thermal_zone17 thermal_zone24 thermal_zone31
> > > thermal_zone39 thermal_zone46 thermal_zone53 thermal_zone60
> > > thermal_zone68 thermal_zone75 thermal_zone82 tz-by-name
> > > cooling_device10 cooling_device18 cooling_device25 cooling_device4
> > > thermal_zone10 thermal_zone18 thermal_zone25 thermal_zone32
> > > thermal_zone4 thermal_zone47 thermal_zone54 thermal_zone61
> > > thermal_zone69 thermal_zone76 thermal_zone83
> > > cooling_device11 cooling_device19 cooling_device26 cooling_device5
> > > thermal_zone11 thermal_zone19 thermal_zone26 thermal_zone33
> > > thermal_zone40 thermal_zone48 thermal_zone55 thermal_zone62
> > > thermal_zone7 thermal_zone77 thermal_zone84
> > > cooling_device12 cooling_device2 cooling_device27 cooling_device6
> > > thermal_zone12 thermal_zone2 thermal_zone27 thermal_zone34
> > > thermal_zone41 thermal_zone49 thermal_zone56 thermal_zone63
> > > thermal_zone70 thermal_zone78 thermal_zone85
> > > cooling_device13 cooling_device20 cooling_device28 cooling_device7
> > > thermal_zone13 thermal_zone20 thermal_zone28 thermal_zone35
> > > thermal_zone42 thermal_zone5 thermal_zone57 thermal_zone64
> > > thermal_zone71 thermal_zone79 thermal_zone86
> > > cooling_device14 cooling_device21 cooling_device29 cooling_device8
> > > thermal_zone14 thermal_zone21 thermal_zone29 thermal_zone36
> > > thermal_zone43 thermal_zone50 thermal_zone58 thermal_zone65
> > > thermal_zone72 thermal_zone8 thermal_zone87
> > >
> > >
> > >> But what userspace code needs to do this, and for what?
> > > In Android, thermal daemon and thermal HAL as well as some init.rc
> > > script would use those thermal paths for managing and monitoring
> > > thermal. The daemon/HAL could have logic pipled in, however Android's
> > > init.rc script would be really tricky.
> > > On a related note, we also create /dev/block/by-name links from userspace.
> > >
> > > Thanks!
> > > -Wei
> > >>
> > >> thanks,
> > >>
> > >> greg k-h
> >
> >
> > --
> > <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
> >