| Message ID | 20191015061349.141448-1-wvw@google.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Zhang Rui |
| Headers | show |
| Series | thermal: create softlink by name for thermal_zone and cooling_device | expand |
On Tue, Oct 15, 2019 at 11:43 AM Wei Wang <wvw@google.com> 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. I like this. > Signed-off-by: Wei Wang <wvw@google.com> > --- > drivers/thermal/thermal_core.c | 23 +++++++++++++++++++++-- > 1 file changed, 21 insertions(+), 2 deletions(-) > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > index d4481cc8958f..0ff8fb1d7b0a 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; > > @@ -954,7 +957,7 @@ __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] || strlen(type) >= THERMAL_NAME_LENGTH) > return ERR_PTR(-EINVAL); This should be a separate fix, if needed. > if (!ops || !ops->get_max_state || !ops->get_cur_state || > @@ -989,9 +992,15 @@ __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"); Any reason not to use the following form instead? It seems easier to read. if (!cdev_link_kobj) { cdev_link_kobj = kobject_create_and_add("cdev-by-name", cdev->device.kobj.parent); ret = sysfs_create_link(cdev_link_kobj, &cdev->device.kobj, cdev->type)) if (ret) dev_err(&cdev->device, "Failed to create cdev-by-name link\n"); } > mutex_unlock(&thermal_list_lock); > > /* Update binding information for 'this' new cdev */ > @@ -1157,6 +1166,8 @@ 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); > > @@ -1340,6 +1351,12 @@ 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"); Same as above. > mutex_unlock(&thermal_list_lock); > > /* Bind cooling devices for this zone */ > @@ -1411,6 +1428,8 @@ 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); > > -- > 2.23.0.700.g56cf767bdb-goog >
On Wed, Oct 16, 2019 at 10:20 PM Amit Kucheria <amit.kucheria@verdurent.com> wrote: > > On Tue, Oct 15, 2019 at 11:43 AM Wei Wang <wvw@google.com> 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. > > I like this. > > > Signed-off-by: Wei Wang <wvw@google.com> > > --- > > drivers/thermal/thermal_core.c | 23 +++++++++++++++++++++-- > > 1 file changed, 21 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > > index d4481cc8958f..0ff8fb1d7b0a 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; > > > > @@ -954,7 +957,7 @@ __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] || strlen(type) >= THERMAL_NAME_LENGTH) > > return ERR_PTR(-EINVAL); > > This should be a separate fix, if needed. > > > if (!ops || !ops->get_max_state || !ops->get_cur_state || > > @@ -989,9 +992,15 @@ __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"); > > Any reason not to use the following form instead? It seems easier to read. > > if (!cdev_link_kobj) { > cdev_link_kobj = kobject_create_and_add("cdev-by-name", > cdev->device.kobj.parent); > ret = sysfs_create_link(cdev_link_kobj, > &cdev->device.kobj, cdev->type)) > if (ret) > dev_err(&cdev->device, "Failed to create > cdev-by-name link\n"); > } I can now see why you had to do that - none of the other links would get created after the first one. Perhaps create the directories in the __init functions and only create the links here? > > mutex_unlock(&thermal_list_lock); > > > > /* Update binding information for 'this' new cdev */ > > @@ -1157,6 +1166,8 @@ 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); > > > > @@ -1340,6 +1351,12 @@ 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"); > > Same as above. > > > mutex_unlock(&thermal_list_lock); > > > > /* Bind cooling devices for this zone */ > > @@ -1411,6 +1428,8 @@ 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); > > > > -- > > 2.23.0.700.g56cf767bdb-goog > >
On Wed, Oct 16, 2019 at 10:16 AM Amit Kucheria <amit.kucheria@verdurent.com> wrote: > > On Wed, Oct 16, 2019 at 10:20 PM Amit Kucheria > <amit.kucheria@verdurent.com> wrote: > > > > On Tue, Oct 15, 2019 at 11:43 AM Wei Wang <wvw@google.com> 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. > > > > I like this. > > > > > Signed-off-by: Wei Wang <wvw@google.com> > > > --- > > > drivers/thermal/thermal_core.c | 23 +++++++++++++++++++++-- > > > 1 file changed, 21 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > > > index d4481cc8958f..0ff8fb1d7b0a 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; > > > > > > @@ -954,7 +957,7 @@ __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] || strlen(type) >= THERMAL_NAME_LENGTH) > > > return ERR_PTR(-EINVAL); > > > > This should be a separate fix, if needed. Agree, but the link now requires that "" as invalid _type_. > > > > > if (!ops || !ops->get_max_state || !ops->get_cur_state || > > > @@ -989,9 +992,15 @@ __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"); > > > > Any reason not to use the following form instead? It seems easier to read. > > > > if (!cdev_link_kobj) { > > cdev_link_kobj = kobject_create_and_add("cdev-by-name", > > cdev->device.kobj.parent); > > ret = sysfs_create_link(cdev_link_kobj, > > &cdev->device.kobj, cdev->type)) > > if (ret) > > dev_err(&cdev->device, "Failed to create > > cdev-by-name link\n"); > > } > > I can now see why you had to do that - none of the other links would > get created after the first one. > > Perhaps create the directories in the __init functions and only create > the links here? > AFAICT, this is no such API except the private get_device_parent() under driver/base/. Also the lazy initialization makes sense in such case when there is no thermal device attached. Looks like the class dir is also lazy-initialized when first device registered https://elixir.bootlin.com/linux/v5.3.5/source/drivers/base/core.c#L1790. > > > > mutex_unlock(&thermal_list_lock); > > > > > > /* Update binding information for 'this' new cdev */ > > > @@ -1157,6 +1166,8 @@ 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); > > > > > > @@ -1340,6 +1351,12 @@ 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"); > > > > Same as above. > > > > > mutex_unlock(&thermal_list_lock); > > > > > > /* Bind cooling devices for this zone */ > > > @@ -1411,6 +1428,8 @@ 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); > > > > > > -- > > > 2.23.0.700.g56cf767bdb-goog > > >
On Thu, Oct 17, 2019 at 3:04 AM Wei Wang <wvw@google.com> wrote: > > On Wed, Oct 16, 2019 at 10:16 AM Amit Kucheria > <amit.kucheria@verdurent.com> wrote: > > > > On Wed, Oct 16, 2019 at 10:20 PM Amit Kucheria > > <amit.kucheria@verdurent.com> wrote: > > > > > > On Tue, Oct 15, 2019 at 11:43 AM Wei Wang <wvw@google.com> 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. > > > > > > I like this. > > > > > > > Signed-off-by: Wei Wang <wvw@google.com> > > > > --- > > > > drivers/thermal/thermal_core.c | 23 +++++++++++++++++++++-- > > > > 1 file changed, 21 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > > > > index d4481cc8958f..0ff8fb1d7b0a 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; > > > > > > > > @@ -954,7 +957,7 @@ __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] || strlen(type) >= THERMAL_NAME_LENGTH) > > > > return ERR_PTR(-EINVAL); > > > > > > This should be a separate fix, if needed. > Agree, but the link now requires that "" as invalid _type_. I'm not sure I understand. What does this change have to do with adding symlinks below? > > > > > > > if (!ops || !ops->get_max_state || !ops->get_cur_state || > > > > @@ -989,9 +992,15 @@ __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"); > > > > > > Any reason not to use the following form instead? It seems easier to read. > > > > > > if (!cdev_link_kobj) { > > > cdev_link_kobj = kobject_create_and_add("cdev-by-name", > > > cdev->device.kobj.parent); > > > ret = sysfs_create_link(cdev_link_kobj, > > > &cdev->device.kobj, cdev->type)) > > > if (ret) > > > dev_err(&cdev->device, "Failed to create > > > cdev-by-name link\n"); > > > } > > > > I can now see why you had to do that - none of the other links would > > get created after the first one. > > > > Perhaps create the directories in the __init functions and only create > > the links here? > > > AFAICT, this is no such API except the private get_device_parent() > under driver/base/. Also the lazy initialization makes sense in such > case when there is no thermal device attached. Looks like the class > dir is also lazy-initialized when first device registered > https://elixir.bootlin.com/linux/v5.3.5/source/drivers/base/core.c#L1790. OK. > > > > > > mutex_unlock(&thermal_list_lock); > > > > > > > > /* Update binding information for 'this' new cdev */ > > > > @@ -1157,6 +1166,8 @@ 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); > > > > > > > > @@ -1340,6 +1351,12 @@ 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"); > > > > > > Same as above. > > > > > > > mutex_unlock(&thermal_list_lock); > > > > > > > > /* Bind cooling devices for this zone */ > > > > @@ -1411,6 +1428,8 @@ 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); > > > > > > > > -- > > > > 2.23.0.700.g56cf767bdb-goog > > > >
On Sun, Nov 10, 2019 at 9:26 PM Amit Kucheria <amit.kucheria@verdurent.com> wrote: > > On Thu, Oct 17, 2019 at 3:04 AM Wei Wang <wvw@google.com> wrote: > > > > On Wed, Oct 16, 2019 at 10:16 AM Amit Kucheria > > <amit.kucheria@verdurent.com> wrote: > > > > > > On Wed, Oct 16, 2019 at 10:20 PM Amit Kucheria > > > <amit.kucheria@verdurent.com> wrote: > > > > > > > > On Tue, Oct 15, 2019 at 11:43 AM Wei Wang <wvw@google.com> 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. > > > > > > > > I like this. > > > > > > > > > Signed-off-by: Wei Wang <wvw@google.com> > > > > > --- > > > > > drivers/thermal/thermal_core.c | 23 +++++++++++++++++++++-- > > > > > 1 file changed, 21 insertions(+), 2 deletions(-) > > > > > > > > > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > > > > > index d4481cc8958f..0ff8fb1d7b0a 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; > > > > > > > > > > @@ -954,7 +957,7 @@ __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] || strlen(type) >= THERMAL_NAME_LENGTH) > > > > > return ERR_PTR(-EINVAL); > > > > > > > > This should be a separate fix, if needed. > > Agree, but the link now requires that "" as invalid _type_. > > I'm not sure I understand. What does this change have to do with > adding symlinks below? > cdev->type will be used later in sysfs_create_link and adding "" as symlink is kind of bad practise AIUI. thanks > > > > > > > > > if (!ops || !ops->get_max_state || !ops->get_cur_state || > > > > > @@ -989,9 +992,15 @@ __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"); > > > > > > > > Any reason not to use the following form instead? It seems easier to read. > > > > > > > > if (!cdev_link_kobj) { > > > > cdev_link_kobj = kobject_create_and_add("cdev-by-name", > > > > cdev->device.kobj.parent); > > > > ret = sysfs_create_link(cdev_link_kobj, > > > > &cdev->device.kobj, cdev->type)) > > > > if (ret) > > > > dev_err(&cdev->device, "Failed to create > > > > cdev-by-name link\n"); > > > > } > > > > > > I can now see why you had to do that - none of the other links would > > > get created after the first one. > > > > > > Perhaps create the directories in the __init functions and only create > > > the links here? > > > > > AFAICT, this is no such API except the private get_device_parent() > > under driver/base/. Also the lazy initialization makes sense in such > > case when there is no thermal device attached. Looks like the class > > dir is also lazy-initialized when first device registered > > https://elixir.bootlin.com/linux/v5.3.5/source/drivers/base/core.c#L1790. > > OK. > > > > > > > > > mutex_unlock(&thermal_list_lock); > > > > > > > > > > /* Update binding information for 'this' new cdev */ > > > > > @@ -1157,6 +1166,8 @@ 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); > > > > > > > > > > @@ -1340,6 +1351,12 @@ 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"); > > > > > > > > Same as above. > > > > > > > > > mutex_unlock(&thermal_list_lock); > > > > > > > > > > /* Bind cooling devices for this zone */ > > > > > @@ -1411,6 +1428,8 @@ 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); > > > > > > > > > > -- > > > > > 2.23.0.700.g56cf767bdb-goog > > > > >
On Mon, Nov 11, 2019 at 11:22 PM Wei Wang <wvw@google.com> wrote: > > On Sun, Nov 10, 2019 at 9:26 PM Amit Kucheria > <amit.kucheria@verdurent.com> wrote: > > > > On Thu, Oct 17, 2019 at 3:04 AM Wei Wang <wvw@google.com> wrote: > > > > > > On Wed, Oct 16, 2019 at 10:16 AM Amit Kucheria > > > <amit.kucheria@verdurent.com> wrote: > > > > > > > > On Wed, Oct 16, 2019 at 10:20 PM Amit Kucheria > > > > <amit.kucheria@verdurent.com> wrote: > > > > > > > > > > On Tue, Oct 15, 2019 at 11:43 AM Wei Wang <wvw@google.com> 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. > > > > > > > > > > I like this. > > > > > > > > > > > Signed-off-by: Wei Wang <wvw@google.com> > > > > > > --- > > > > > > drivers/thermal/thermal_core.c | 23 +++++++++++++++++++++-- > > > > > > 1 file changed, 21 insertions(+), 2 deletions(-) > > > > > > > > > > > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > > > > > > index d4481cc8958f..0ff8fb1d7b0a 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; > > > > > > > > > > > > @@ -954,7 +957,7 @@ __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] || strlen(type) >= THERMAL_NAME_LENGTH) > > > > > > return ERR_PTR(-EINVAL); > > > > > > > > > > This should be a separate fix, if needed. > > > Agree, but the link now requires that "" as invalid _type_. > > > > I'm not sure I understand. What does this change have to do with > > adding symlinks below? > > > > cdev->type will be used later in sysfs_create_link and adding "" as > symlink is kind of bad practise AIUI. > Perhaps I'm being dense here, in which case my apologies. But what stops us from splitting the patch into two? 1. Make type == "" as invalid by using your change above and fixing up the strlcpy(cdev->type....) further down. 2. Create the actual symlinks in a separate patch. Regards, Amit > > > > > > > > > > > if (!ops || !ops->get_max_state || !ops->get_cur_state || > > > > > > @@ -989,9 +992,15 @@ __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"); > > > > > > > > > > Any reason not to use the following form instead? It seems easier to read. > > > > > > > > > > if (!cdev_link_kobj) { > > > > > cdev_link_kobj = kobject_create_and_add("cdev-by-name", > > > > > cdev->device.kobj.parent); > > > > > ret = sysfs_create_link(cdev_link_kobj, > > > > > &cdev->device.kobj, cdev->type)) > > > > > if (ret) > > > > > dev_err(&cdev->device, "Failed to create > > > > > cdev-by-name link\n"); > > > > > } > > > > > > > > I can now see why you had to do that - none of the other links would > > > > get created after the first one. > > > > > > > > Perhaps create the directories in the __init functions and only create > > > > the links here? > > > > > > > AFAICT, this is no such API except the private get_device_parent() > > > under driver/base/. Also the lazy initialization makes sense in such > > > case when there is no thermal device attached. Looks like the class > > > dir is also lazy-initialized when first device registered > > > https://elixir.bootlin.com/linux/v5.3.5/source/drivers/base/core.c#L1790. > > > > OK. > > > > > > > > > > > > mutex_unlock(&thermal_list_lock); > > > > > > > > > > > > /* Update binding information for 'this' new cdev */ > > > > > > @@ -1157,6 +1166,8 @@ 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); > > > > > > > > > > > > @@ -1340,6 +1351,12 @@ 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"); > > > > > > > > > > Same as above. > > > > > > > > > > > mutex_unlock(&thermal_list_lock); > > > > > > > > > > > > /* Bind cooling devices for this zone */ > > > > > > @@ -1411,6 +1428,8 @@ 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); > > > > > > > > > > > > -- > > > > > > 2.23.0.700.g56cf767bdb-goog > > > > > >
On Wed, Dec 4, 2019 at 4:45 AM Amit Kucheria <amit.kucheria@verdurent.com> wrote: > > On Mon, Nov 11, 2019 at 11:22 PM Wei Wang <wvw@google.com> wrote: > > > > On Sun, Nov 10, 2019 at 9:26 PM Amit Kucheria > > <amit.kucheria@verdurent.com> wrote: > > > > > > On Thu, Oct 17, 2019 at 3:04 AM Wei Wang <wvw@google.com> wrote: > > > > > > > > On Wed, Oct 16, 2019 at 10:16 AM Amit Kucheria > > > > <amit.kucheria@verdurent.com> wrote: > > > > > > > > > > On Wed, Oct 16, 2019 at 10:20 PM Amit Kucheria > > > > > <amit.kucheria@verdurent.com> wrote: > > > > > > > > > > > > On Tue, Oct 15, 2019 at 11:43 AM Wei Wang <wvw@google.com> 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. > > > > > > > > > > > > I like this. > > > > > > > > > > > > > Signed-off-by: Wei Wang <wvw@google.com> > > > > > > > --- > > > > > > > drivers/thermal/thermal_core.c | 23 +++++++++++++++++++++-- > > > > > > > 1 file changed, 21 insertions(+), 2 deletions(-) > > > > > > > > > > > > > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > > > > > > > index d4481cc8958f..0ff8fb1d7b0a 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; > > > > > > > > > > > > > > @@ -954,7 +957,7 @@ __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] || strlen(type) >= THERMAL_NAME_LENGTH) > > > > > > > return ERR_PTR(-EINVAL); > > > > > > > > > > > > This should be a separate fix, if needed. > > > > Agree, but the link now requires that "" as invalid _type_. > > > > > > I'm not sure I understand. What does this change have to do with > > > adding symlinks below? > > > > > > > cdev->type will be used later in sysfs_create_link and adding "" as > > symlink is kind of bad practise AIUI. > > > > Perhaps I'm being dense here, in which case my apologies. > > But what stops us from splitting the patch into two? > 1. Make type == "" as invalid by using your change above and fixing up > the strlcpy(cdev->type....) further down. > 2. Create the actual symlinks in a separate patch. > > Regards, > Amit > Updated with v2, thanks. > > > > > > > > > > > > > > if (!ops || !ops->get_max_state || !ops->get_cur_state || > > > > > > > @@ -989,9 +992,15 @@ __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"); > > > > > > > > > > > > Any reason not to use the following form instead? It seems easier to read. > > > > > > > > > > > > if (!cdev_link_kobj) { > > > > > > cdev_link_kobj = kobject_create_and_add("cdev-by-name", > > > > > > cdev->device.kobj.parent); > > > > > > ret = sysfs_create_link(cdev_link_kobj, > > > > > > &cdev->device.kobj, cdev->type)) > > > > > > if (ret) > > > > > > dev_err(&cdev->device, "Failed to create > > > > > > cdev-by-name link\n"); > > > > > > } > > > > > > > > > > I can now see why you had to do that - none of the other links would > > > > > get created after the first one. > > > > > > > > > > Perhaps create the directories in the __init functions and only create > > > > > the links here? > > > > > > > > > AFAICT, this is no such API except the private get_device_parent() > > > > under driver/base/. Also the lazy initialization makes sense in such > > > > case when there is no thermal device attached. Looks like the class > > > > dir is also lazy-initialized when first device registered > > > > https://elixir.bootlin.com/linux/v5.3.5/source/drivers/base/core.c#L1790. > > > > > > OK. > > > > > > > > > > > > > > > mutex_unlock(&thermal_list_lock); > > > > > > > > > > > > > > /* Update binding information for 'this' new cdev */ > > > > > > > @@ -1157,6 +1166,8 @@ 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); > > > > > > > > > > > > > > @@ -1340,6 +1351,12 @@ 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"); > > > > > > > > > > > > Same as above. > > > > > > > > > > > > > mutex_unlock(&thermal_list_lock); > > > > > > > > > > > > > > /* Bind cooling devices for this zone */ > > > > > > > @@ -1411,6 +1428,8 @@ 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); > > > > > > > > > > > > > > -- > > > > > > > 2.23.0.700.g56cf767bdb-goog > > > > > > >
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index d4481cc8958f..0ff8fb1d7b0a 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; @@ -954,7 +957,7 @@ __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] || strlen(type) >= THERMAL_NAME_LENGTH) return ERR_PTR(-EINVAL); if (!ops || !ops->get_max_state || !ops->get_cur_state || @@ -989,9 +992,15 @@ __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 */ @@ -1157,6 +1166,8 @@ 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); @@ -1340,6 +1351,12 @@ 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 */ @@ -1411,6 +1428,8 @@ 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);
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 <wvw@google.com> --- drivers/thermal/thermal_core.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-)